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How to connect Firebase to Android Studio Manually. Firebase Android Studio Tutorial.
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“System services not available to Activities before onCreate …

I think it’s because your instantiating an onClick listener before on create is called. Try instantiating the onClick listener inse the …

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System services not available to Activities before onCreate()

Hi, I have a ListActivity and in its onCreate()-method I want to create a new ListAdapter: adapter = new …

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MethodChannel System Services not available to Activities …

IllegalStateException: System services not available to Activities before onCreate() > at andro.app.Activity.

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System services not available to Activities before onCreate()

Java.Lang.IllegalStateException: System services not available to Activities before onCreate(). This is the code part throwing the exception:

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java.lang.IllegalStateException: System services not available …

刚刚写垂重跑马灯demo的时候，被报了一个 System services not available to Activities before onCreate() 错误. 错误日志如下：.

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System services not available to Activities before onCreate

java.lang.IllegalStateException: System services not available to Activities before onCreate() This situation is generally due to the use of the new keyword …

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在onCreate() 之前，Activity 無法使用Android 系統服務 …

問題描述在onCreate() 之前，Activity 無法使用Andro 系統服務(Andro System services not available to Activities before onCreate()) .

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System services not available to Activities before onCreate()

System services not available to Activities before onCreate(). This is my RecyclerView.Adapter with the onBindViewHolder()

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주제와 관련된 이미지 system services not available to activities before oncreate

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주제에 대한 기사 평가 system services not available to activities before oncreate

• Author: CubixSol
• Views: 조회수 52,680회
• Likes: 좋아요 564개
• Date Published: 2020. 10. 18.
• Video Url link: https://www.youtube.com/watch?v=nep85PD8U7M

Is onCreate only called once?

@OnCreate is only for initial creation, and thus should only be called once. If you have any processing you wish to complete multiple times you should put it elsewhere, perhaps in the @OnResume method.

What does the onCreate do in Android?

onCreate(Bundle savedInstanceState) Function in Android:

When an Activity first call or launched then onCreate(Bundle savedInstanceState) method is responsible to create the activity.

What is super onCreate in Android?

By calling super. onCreate(savedInstanceState); , you tell the Dalvik VM to run your code in addition to the existing code in the onCreate() of the parent class. If you leave out this line, then only your code is run.

Why do we override onCreate?

onCreate is “Overridden” because Activity has an existing implementation that your class MainActivity is replacing with it’s own implementation. you would say “implemented” if the method is only declared in an interface, but there is no implementation in a super class your are replacing.

What is it called when an application is onCreate?

onCreate() – called before the first components of the application starts. onLowMemory() – called when the Android system requests that the application cleans up memory. onTrimMemory() – called when the Android system requests that the application cleans up memory.

What is the difference between onCreate () and onStart ()?

onCreate() is called when the when the activity is first created. onStart() is called when the activity is becoming visible to the user.

What does onCreate mean?

onCreate is used to start an activity. super is used to call the parent class constructor. setContentView is used to set the xml.

What is the argument for onCreate function used for?

onCreate(Bundle) is called when the activity first starts up. You can use it to perform one-time initialization such as creating the user interface. onCreate() takes one parameter that is either null or some state information previously saved by the onSaveInstanceState .

What is Gmail activity?

Data helps make Google services more useful for you. Sign in to review and manage your activity, including things you’ve searched for, websites you’ve visited, and videos you’ve watched.

How do you use onCreate method?

What is the purpose of super onCreate () in Android Mcq?

Q 9 – What is the purpose of super. onCreate() in android? The super. onCreate() will create the graphical window for subclasses and place at onCreate() method.

What is Android super?

The super keyword refers to superclass (parent) objects. It is used to call superclass methods, and to access the superclass constructor.

Why do we need to call setContentView () in onCreate () of activity class?

As onCreate() of an Activity is called only once, this is the point where most initialization should go: calling setContentView(int) to inflate the activity’s UI, using findViewById to programmatically interact with widgets in the UI, calling managedQuery(android.

Can we create activity without UI in Android?

Explanation. Generally, every activity is having its UI(Layout). But if a developer wants to create an activity without UI, he can do it.

What is the difference between onStop and onDestroy?

Once onStop() is called then onRestart() can be called. onDestroy() is last in the order after onStop(). onDestory() is called just before an activity is destroyed and after that it is gone it is not possible to resurrect this.

How do you use onCreate method?

What is the use of onCreate bundle savedInstanceState in Android?

The savedInstanceState is a reference to a Bundle object that is passed into the onCreate method of every Android Activity. Activities have the ability, under special circumstances, to restore themselves to a previous state using the data stored in this bundle.

What does setOnClickListener do in Android?

OnClickListener and wires the listener to the button using setOnClickListener(View. OnClickListener) . As a result, the system executes the code you write in onClick(View) after the user presses the button. The system executes the code in onClick on the main thread.

What is the use of SetContentView in Android?

“System services not available to Activities before onCreate()” Error message?

When the user hits an icon in my app, I want the app first to check if the device is connected to the internet and then do something depending on the result it receives (for know it’s just popping up a dialog, informing whether the device is connected or not). So I wrote this code:

public class MainActivity extends Activity { // SOME CONSTANTS WILL BE DEFINED HERE AlertDialog.Builder builder = new AlertDialog.Builder(this); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.icoMyIcon).setOnClickListener(listener); } private OnClickListener listener = new OnClickListener() { public void onClick(View v) { if (isNetworkConnected()) { builder.setMessage(“Internet connected!”).setCancelable(false) .setPositiveButton(“OK”, null); builder.create().show(); } else { builder.setMessage(“Internet isn\’t connected!”) .setCancelable(false) .setPositiveButton(“OK”, null); builder.create().show(); } } }; // Check if the device is connected to the Internet private boolean isNetworkConnected() { ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo ni = cm.getActiveNetworkInfo(); if (ni == null) { // There are no active networks. return false; } else return true; } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } }

When I’m trying to run this App on the emulator it keeps crushing and I’m getting this Error messages in LogCat:

07-24 22:59:45.034: E/AndroidRuntime(894): FATAL EXCEPTION: main 07-24 22:59:45.034: E/AndroidRuntime(894): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.my.app/com.my.app.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate() 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.os.Handler.dispatchMessage(Handler.java:99) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.os.Looper.loop(Looper.java:123) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread.main(ActivityThread.java:4627) 07-24 22:59:45.034: E/AndroidRuntime(894): at java.lang.reflect.Method.invokeNative(Native Method) 07-24 22:59:45.034: E/AndroidRuntime(894): at java.lang.reflect.Method.invoke(Method.java:521) 07-24 22:59:45.034: E/AndroidRuntime(894): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 07-24 22:59:45.034: E/AndroidRuntime(894): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 07-24 22:59:45.034: E/AndroidRuntime(894): at dalvik.system.NativeStart.main(Native Method) 07-24 22:59:45.034: E/AndroidRuntime(894): Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate() 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.Activity.getSystemService(Activity.java:3526) 07-24 22:59:45.034: E/AndroidRuntime(894): at com.android.internal.app.AlertController$AlertParams.(AlertController.java:743) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.AlertDialog$Builder.(AlertDialog.java:273) 07-24 22:59:45.034: E/AndroidRuntime(894): at com.my.app.MainActivity.(MainActivity.java:24) 07-24 22:59:45.034: E/AndroidRuntime(894): at java.lang.Class.newInstanceImpl(Native Method) 07-24 22:59:45.034: E/AndroidRuntime(894): at java.lang.Class.newInstance(Class.java:1429) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 07-24 22:59:45.034: E/AndroidRuntime(894): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) 07-24 22:59:45.034: E/AndroidRuntime(894): … 11 more

Why is it happening and how do I fix it? I’m a novice at this, so… please be gentle! 🙂

System services not available to Activities before onCreate() · Issue #651 · robolectric/robolectric

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Why do OnCreate should be called only once on the start of Activity?

I would like to know, why OnCreate() is called only once at the start of an activity?

Can we call OnCreate() more than once in the same activity?

If yes, than how can we call it? can anyone give an example?

Thanks a lot!!!

onCreate(Bundle savedInstanceState) Activity Function And Example In Android

onCreate(Bundle savedInstanceState) Function in Android:

When an Activity first call or launched then onCreate(Bundle savedInstanceState) method is responsible to create the activity.

When ever orientation(i.e. from horizontal to vertical or vertical to horizontal) of activity gets changed or when an Activity gets forcefully terminated by any Operating System then savedInstanceState i.e. object of Bundle Class will save the state of an Activity.

After Orientation changed then onCreate(Bundle savedInstanceState) will call and recreate the activity and load all data from savedInstanceState.

Basically Bundle class is used to stored the data of activity whenever above condition occur in app.

onCreate() is not required for apps. But the reason it is used in app is because that method is the best place to put initialization code.

You could also put your initialization code in onStart() or onResume() and when you app will load first, it will work same as in onCreate().

Example of onCreate(Bundle savedInstanceState):

Lets create a simple program to understand onCreate(Bundle savedInstanceState) more deeply.

In the below example we will ask the user to Enter the name, save his name in Bundle object and then display the same name when user rotates the screen.

First create a new project, name it Exampleoncreate and create a activity name MainActivity. Also create a content_main.xml in layout if not present by default.

For designing UI we will create 3 things in content_main.xml:

We have used Linear Layout

a TextView to display basic detail about the program to user,

EditText where user will enter the name which will be save in Bundle object

a TextView which will display the name on screen rotation

Below is the complete code of content_main.xml

Now go to MainActivity.java and paste the below code. The explanation is given using comments in the code itself.

import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.EditText; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private static String TAG = “ActivityName”; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.content_main); } //Saving The Text Entered by User protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); Log.i(TAG, “onSaveInstanceState”); final EditText editText= (EditText) findViewById(R.id.editText);// getting the reference of editext from xml CharSequence text = editText.getText();// getting text u entered in edittext outState.putCharSequence(“savedText”, text);// saved that text in bundle object i.e. outState } //Restoring the State @Override protected void onRestoreInstanceState(Bundle savedInstanceState) { super.onRestoreInstanceState(savedInstanceState); Log.i(TAG, “onRestoreInstanceState”); final TextView textView = (TextView) findViewById(R.id.textView);// getting the reference of textview from xml CharSequence savedText= savedInstanceState.getCharSequence(“savedText”);// getting the text of editext textView.setText(savedText);// set the text that is retrieved from bundle object } }

Make sure MainActivity is mentioned in Manifest file. Below is the code of AndroidManifest.xml

Output:

Now run the application in Emulator and enter the name. In our case we have entered AbhiAndroid.

Now rotate the screen from vertical to horizontal (Press ctrl + F12 in Windows & Fn+Left CTRL+F12 on Mac to rotate). After you change screen orientation you will see the same name appear just right side of name.

So we have retrieved the data from Bundle object.

super.onCreate(savedInstanceState);

Every Activity you make is started through a sequence of method calls. onCreate() is the first of these calls.

Each and every one of your Activities extends android.app.Activity either directly or by subclassing another subclass of Activity .

In Java, when you inherit from a class, you can override its methods to run your own code in them. A very common example of this is the overriding of the toString() method when extending java.lang.Object .

When we override a method, we have the option of completely replacing the method in our class, or of extending the existing parent class’ method. By calling super.onCreate(savedInstanceState); , you tell the Dalvik VM to run your code in addition to the existing code in the onCreate() of the parent class. If you leave out this line, then only your code is run. The existing code is ignored completely.

However, you must include this super call in your method, because if you don’t then the onCreate() code in Activity is never run, and your app will run into all sorts of problem like having no Context assigned to the Activity (though you’ll hit a SuperNotCalledException before you have a chance to figure out that you have no context).

Why is onCreate overridden?

onCreate is “Overridden” because Activity has an existing implementation that your class MainActivity is replacing with it’s own implementation. you would say “implemented” if the method is only declared in an interface, but there is no implementation in a super class your are replacing.

the annotation @Override is an optional (but recommanded) hint for the compiler that the following method signature must exists in the super class or interface your are extending. It will result in an compile error if this is not the case. It’s also a hint for the developer that this method also exists in the super class.

MethodChannel System Services not available to Activities before onCreate() [Kotlin]

Issue

I tried create my custom plugin for Flutter on Kotlin. I accessed the methodChannel and was able to do it, but when I want to use the bluetooth service in the methodChannel i am faicng this error. I did on Kotlin and my code ran correctly. The difference is My kotlin app’s class is of type AppCompatActivity() and has onCreate() function. My problem was not solved when I added the onCreate function to my scanner.kt file. I get this error.

> E/MethodChannel#beacon_scanner: Failed to handle method call > java.lang.IllegalStateException: System services not available to Activities before onCreate() > at android.app.Activity.getSystemService(Activity.java:6868) > at com.example.beacon_scanner.BeaconScannerPlugin$onMethodCall$bluetoothAdapter$2.invoke(BeaconScannerPlugin.kt:52) > at com.example.beacon_scanner.BeaconScannerPlugin$onMethodCall$bluetoothAdapter$2.invoke(BeaconScannerPlugin.kt:49) > at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74) > at com.example.beacon_scanner.BeaconScannerPlugin.onMethodCall$lambda-0(BeaconScannerPlugin.kt:49) > at com.example.beacon_scanner.BeaconScannerPlugin.onMethodCall(BeaconScannerPlugin.kt:57) > at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262) > at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296) > at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320) > at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown > Source:12) > at android.os.Handler.handleCallback(Handler.java:938) > at android.os.Handler.dispatchMessage(Handler.java:99) > at android.os.Looper.loopOnce(Looper.java:201) > at android.os.Looper.loop(Looper.java:288) > at android.app.ActivityThread.main(ActivityThread.java:7839) > at java.lang.reflect.Method.invoke(Native Method) > at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) > at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003) > E/flutter: [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled > Exception: PlatformException(error, System services not available to > Activities before onCreate(), null, java.lang.IllegalStateException: > System services not available to Activities before onCreate() > at android.app.Activity.getSystemService(Activity.java:6868) > at com.example.beacon_scanner.BeaconScannerPlugin$onMethodCall$bluetoothAdapter$2.invoke(BeaconScannerPlugin.kt:52) > at com.example.beacon_scanner.BeaconScannerPlugin$onMethodCall$bluetoothAdapter$2.invoke(BeaconScannerPlugin.kt:49) > at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74) > at com.example.beacon_scanner.BeaconScannerPlugin.onMethodCall$lambda-0(BeaconScannerPlugin.kt:49) > at com.example.beacon_scanner.BeaconScannerPlugin.onMethodCall(BeaconScannerPlugin.kt:57) > at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262) > at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296) > at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320) > at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown > Source:12) > at android.os.Handler.handleCallback(Handler.java:938) > at android.os.Handler.dispatchMessage(Handler.java:99) > at android.os.Looper.loopOnce(Looper.java:201) > at android.os.Looper.loop(Looper.java:288) > at android.app.ActivityThread.main(ActivityThread.java:7839) > at java.lang.reflect.Method.invoke(Native Method) > at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) > at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003) > ) > #0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7) > #1 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:177:18) > > #2 BeaconScanner.bluetoothIsActive (package:beacon_scanner/beacon_scanner.dart:14:12) > > #3 _MyAppState.getBtStatus (package:beacon_scanner_example/main.dart:50:17) >

And that’s my code:

scanner.dart

class BeaconScanner { static const MethodChannel _channel = MethodChannel(‘beacon_scanner’); static Future get platformVersion async { final String? version = await _channel.invokeMethod(‘getPlatformVersion’); return version; } static Future get bluetoothIsActive async { return await _channel.invokeMethod(‘bluetoothIsActive’); } static Future get sayHello async { final btStatus = await _channel.invokeMethod(‘sayHello’); return btStatus.toString(); } }

scanner.kt

class BeaconScannerPlugin: FlutterActivity(), FlutterPlugin, MethodCallHandler { private lateinit var channel : MethodChannel private val bluetoothAdapter: BluetoothAdapter by lazy{ (getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager).adapter } companion object { private const val BLUETOOTH_PERMISSION_REQUEST_CODE = 9999 } override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) { channel = MethodChannel(flutterPluginBinding.binaryMessenger, “beacon_scanner”) channel.setMethodCallHandler(this) } override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) { if (call.method == “getPlatformVersion”) { result.success(“Android ${android.os.Build.VERSION.RELEASE}”) } else if (call.method==”bluetoothIsActive”) { if(bluetoothAdapter != null){ if (ActivityCompat.checkSelfPermission( this, Manifest.permission.BLUETOOTH_CONNECT ) != PackageManager.PERMISSION_GRANTED ) { initializeBluetoothOrRequestPermission() } if(bluetoothAdapter.enable()){ result.success(“bt status is ${bluetoothAdapter.isEnabled}”) Log.v(“Scanner”,”ENABLED”) } else { initializeBluetoothOrRequestPermission() } } }else if (call.method==”sayHello”) { result.success(“bt status is HELLO YES”) } else { result.notImplemented() } } private fun initializeBluetoothOrRequestPermission() { val requiredPermissions = listOf(Manifest.permission.BLUETOOTH_CONNECT, Manifest.permission.BLUETOOTH_SCAN) val missingPermissions = requiredPermissions.filter { permission -> ActivityCompat.checkSelfPermission(this,permission) != PackageManager.PERMISSION_GRANTED } if (missingPermissions.isEmpty()) { } else { ActivityCompat.requestPermissions(this, missingPermissions.toTypedArray(), BLUETOOTH_PERMISSION_REQUEST_CODE) } } override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) { channel.setMethodCallHandler(null) } }

Solution

Your BeaconScannerPlugin is an Activity and as the error stacktrace says, it needs to be in the created state before you can use it in getSystemService(Context.BLUETOOTH_SERVICE) .

You should change your BeaconScannerPlugin implementation to not depend on FlutterActivity and instead use ActivityAware interface.

ActivityAware will give you an instace of activity that you can use to get the bluetooth service for your plugin.

You can read more on the official flutter webiste

Answered By – Amr Yousef

Java.Lang.IllegalStateException: System services not available to Activities before onCreate()

Instead you should use a receiver to get notified of network changes. Besides checking for network state isn’t really an expensive operation and can be done in the UI thread I think. Actually the way you are doing it it probably worse. Anyway I use a BroadcastReceiver to find the changes in the network state, something like:

[BroadcastReceiver] public class NetworkStateReceiver: BroadcastReceiver { public event EventHandler ConnectionBroadcast; public override void OnReceive(Context context, Intent intent) { if (ConnectionBroadcast != null) ConnectionBroadcast(this, EventArgs.Empty); } }

And then this code to start receiving network state changes:

`NetworkStateReceiver receiver = new NetworkStateReceiver(); receiver.ConnectionBroadcast += UpdateConnectionState; Context.RegisterReceiver(receiver, new IntentFilter(ConnectivityManager.ConnectivityAction));

private void UpdateConnectionState() { ConnectivityManager connectivityManager = (ConnectivityManager)Context.GetSystemService(Context.ConnectivityService); NetworkInfo activeNetworkInfo = connectivityManager.ActiveNetworkInfo; if (activeNetworkInfo != null && activeNetworkInfo.IsConnected) { IsConnected = true; } else { IsConnected = false; } }`

and don’t forget to unregister receiver when done:

Caused by: java.lang.IllegalStateException: System services not available to Activities before onCre

刚刚写垂重跑马灯demo的时候，被报了一个 System services not available to Activities before onCreate() 错误

错误日志如下：

05-18 17:13:24.634 1598-1598/? E/AndroidRuntime: FATAL EXCEPTION: main Process: com.verticalmarquee.maomao.verticalmarqueedemo, PID: 1598 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.verticalmarquee.maomao.verticalmarqueedemo/com.verticalmarquee.maomao.verticalmarqueedemo.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate() at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2354) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5529) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635) Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate() at android.app.Activity.getSystemService(Activity.java:5293) at android.view.LayoutInflater.from(LayoutInflater.java:229) at com.verticalmarquee.maomao.verticalmarqueedemo.MainActivity.(MainActivity.java:15) at java.lang.Class.newInstance(Native Method) at android.app.Instrumentation.newActivity(Instrumentation.java:1067) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2344) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5529) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635) 复制

我以为是自己在onCreate里面启动跑马灯动画的原因，但细想一下，不对啊，动画至少延时2秒之后执行，一个小demo，不至于启动这么慢吧？

最后发现我做了一个偷懒的操作。

因为跑马灯需要inflate很多个View，所以我将初始化LayoutInflater的操作放在了Activity的属性里面。

public class MainActivity extends AppCompatActivity { private VerticalMarqueeLayout marqueeRoot; private LayoutInflater mInflater = LayoutInflater.from(this); @Override protected void onCreate(Bundle savedInstanceState) { } } 复制

为什么作为属性就会导致应用挂掉了呢？

原因分析：

通过错误日志的堆栈信息顺藤摸瓜找到了Activity启动的位置。

@Override public Activity handleLaunchActivity(ActivityClientRecord r, PendingTransactionActions pendingActions, Intent customIntent) { … final Activity a = performLaunchActivity(r, customIntent); if (a != null) { r.createdConfig = new Configuration(mConfiguration); reportSizeConfigurations(r); if (!r.activity.mFinished && pendingActions != null) { pendingActions.setOldState(r.state); pendingActions.setRestoreInstanceState(true); pendingActions.setCallOnPostCreate(true); } } else { // If there was an error, for any reason, tell the activity manager to stop us. try { ActivityManager.getService() .finishActivity(r.token, Activity.RESULT_CANCELED, null, Activity.DONT_FINISH_TASK_WITH_ACTIVITY); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } return a; } 复制

跟进去看performLaunchActivity(r, customIntent);的代码，发现activity实例化之后调用了activity.attach（）方法。

/** Core implementation of activity launch. */ private Activity performLaunchActivity(ActivityClientRecord r, Intent customIntent) { … ContextImpl appContext = createBaseContextForActivity(r); Activity activity = null; try { java.lang.ClassLoader cl = appContext.getClassLoader(); activity = mInstrumentation.newActivity( cl, component.getClassName(), r.intent); … } catch (Exception e) { … } try { Application app = r.packageInfo.makeApplication(false, mInstrumentation); if (activity != null) { CharSequence title = r.activityInfo.loadLabel(appContext.getPackageManager()); Configuration config = new Configuration(mCompatConfiguration); … activity.attach(appContext, this, getInstrumentation(), r.token, r.ident, app, r.intent, r.activityInfo, title, r.parent, r.embeddedID, r.lastNonConfigurationInstances, config, r.referrer, r.voiceInteractor, window, r.configCallback); … r.activity = activity; } r.setState(ON_CREATE); mActivities.put(r.token, r); } catch (SuperNotCalledException e) { throw e; } catch (Exception e) { if (!mInstrumentation.onException(activity, e)) { throw new RuntimeException( “Unable to start activity ” + component + “: ” + e.toString(), e); } } return activity; } 复制

我的报错位置就是在Activity实例化的时候。我们再看看LayoutInflater.from(this);里面的源码发现：它是通过Context获取到一个layout_inflater的Service。

public static LayoutInflater from(Context context) { LayoutInflater LayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); if (LayoutInflater == null) { throw new AssertionError(“LayoutInflater not found.”); } return LayoutInflater; } 复制

然而Activity的Context是在attach方法里面才绑定，在实例化Activity的过程中，Activity里面不包含可用的Context。

final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token, int ident, Application application, Intent intent, ActivityInfo info, CharSequence title, Activity parent, String id, NonConfigurationInstances lastNonConfigurationInstances, Configuration config, String referrer, IVoiceInteractor voiceInteractor, Window window, ActivityConfigCallback activityConfigCallback) { attachBaseContext(context); } 复制

总结：

Activity初始化之后，如果activity不为null，回调用activity.attach(…)方法，attach方法里面的attachBaseContext（context）方法会将context实例与activity实例绑定在一起。

问题原因：

由于我在Activity初始化的时候写了LayoutInflater.from(this);而执行LayoutInflater.from(this);代码的时候传入的Context是不可用的。最后在查找Service的时候抛出了异常。

得到的教训：

不是所有省空间的做法都是对的，不能打破原有的规律；

源码要常翻翻，了解了原理才能更好的掌控代码；

（标签：Activity、LayoutInflater、Context）

android java.lang.IllegalStateException: System services not available to Activities before onCreate

java.lang.IllegalStateException: System services not available to Activities before onCreate()

This situation is generally due to the use of the new keyword to instantiate the Activity class, which is wrong. Because Activity is created and managed by the system through ActivityManagerService. After new, the object is created, but the Activity is not created. You must know that the object of the Activity is not the same as what it really represents in Android. After the object is created, the system needs to perform a series of init and management. During the creation process, the onCreate method in Acitivity will be called back. After this method is called, it can be explained that the Activity is created.

So you can’t use the new keyword to instantiate the Activity object, you must instantiate the Activity object by way of startActivity.

System services not available to Activities before onCreate() while opening a Dialog from RecyclerView

I’m having this error out of the blue and have no idea what’s causing it or where it has come from.

Basically I’ve got a RecyclerView that gets populated with products. When a product is selected, I’ve got a custom Dialog that pops up where the user can increase product quantity or remove the product. This all works, however if I click the same product a second time it crashes the app with the following error:

System services not available to Activities before onCreate()

This is my RecyclerView.Adapter with the onBindViewHolder()

public class OrderAdapter extends RecyclerView.Adapter{ @Override public void onBindViewHolder(@NonNull OrderAdapter.MyViewHolder holder, int position) { final Item Item = ItemList.get(position); holder.cardView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { dialog = new Dialog(context,R.style.Custom_Theme_Dialog); //Code breaks on this line dialog.setContentView(R.layout.dialog_cart_edit); cartProdDesc = dialog.findViewById(R.id.lblcartProdDesc); cartQuantity = dialog.findViewById(R.id.edit_quantity); btnDone = dialog.findViewById(R.id.btn_dialog_done); btnRemove = dialog.findViewById(R.id.btn_dialog_remove); addQuantity = dialog.findViewById(R.id.addition_action); minusQuantity = dialog.findViewById(R.id.minus_action); cartProdDesc.setText(cartItem.getProductDescription()); cartPackSize.setText(cartItem.getPackSize()); addQuantity.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { try{ quantity = Integer.parseInt(cartQuantity.getText().toString()); } catch (NumberFormatException nf) { Log.e(“Number Exception”,”Number Is Blank”); quantity = 0; } catch (Exception e){ Log.e(“ERROR”,e.toString()); } cartQuantity.setText(String.valueOf(++quantity)); } }); minusQuantity.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { try{ quantity = Integer.parseInt(cartQuantity.getText().toString()); } catch (NumberFormatException nf) { Log.e(“Number Exception”,”Number Is Blank”); quantity = 0; } catch (Exception e){ Log.e(“ERROR”,e.toString()); } cartQuantity.setText(String.valueOf(–quantity)); } }); btnDone.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if(cartQuantity.getText().toString().isEmpty() || cartQuantity.getText().toString().equals(“0”) || cartQuantity.getText().toString().contains(“-“)){ cartQuantity.setError(“Enter a valid quantity”); } else { newQuantity = cartQuantity.getText().toString(); db.updateCartItem(new CartItem(cartItem.getId(),cartItem.getProductCode(),cartItem.getBarcode(),cartItem.getNappiCode(),cartItem.getProductDescription(),cartItem.getPackSize(),newQuantity)); updateDataSet(); notifyDataSetChanged(); dialog.dismiss(); } } }); btnRemove.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { DialogInterface.OnClickListener dialogClickListner = new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int which) { switch (which){ case DialogInterface.BUTTON_POSITIVE: db.deleteCartItem(cartItem.getId()); updateDataSet(); dialog.dismiss(); break; case DialogInterface.BUTTON_NEGATIVE: dialog.dismiss(); break; } } }; AlertDialog.Builder builder = new AlertDialog.Builder(context); builder.setMessage(“Are you sure you want to remove ” + cartItem.getProductDescription()).setPositiveButton(“Yes”,dialogClickListner).setNegativeButton(“No”,dialogClickListner).show(); } }); dialog.show(); } }); } }

I’ve got a private Dialog dialog; declaration further up on the Activity in case anyone was wondering.

The code breaks on the dialog = new Dialog(context,R.style.Custom_Theme_Dialog); however if I comment out the dialog.show() at the end I have no issues, apart from the dialog not showing, but that tells me that the problem isn’t with the assigning of the dialog, or am I wrong on this train of thought ?

This is a line of code in my OrderActivity where I’m calling the adapter, I’m sending the context from here.

OrderAdapter = new OrderAdapter(this,ItemList);

This is my constructor where I’m assigning Context

키워드에 대한 정보 system services not available to activities before oncreate

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