如何在另一個活動中顯示警報對話框？

Question

我想說明一個警告對話框非活性類主要活動類getversion方法的方法，但每當我通過這個方法調用AlertDialog它與下面的文本

public void AlertUpgrade(Activity activity) { 

    Log.e("AlertUpgrade", "Communicator."); 
    AlertDialog.Builder builder = new AlertDialog.Builder(activity); 
    builder.setMessage(" Click OK to Upgrade Now ? ") 
     .setPositiveButton("OK" + 
      "", new DialogInterface.OnClickListener() { 

     public void onClick(DialogInterface dialog, int id) { 

      Log.e("onClick", "AlertUpgrade"); 
      Intent marketIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=gsip.webgalaxy")); 
      marketIntent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET|Intent.FLAG_ACTIVITY_MULTIPLE_TASK); 
      app_context.startActivity(marketIntent); 
     } 
    }).setOnKeyListener(new OnKeyListener() { 

     @Override 
     public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) { 
      if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_UP) { 
       return false; 
      } 

      return true; 
     } 
    }); 
    builder.create().show(); 
} 

public void AlertUpdate(Activity activity) { 

    Log.e("AlertUpdate", "Communicator....."); 
    AlertDialog.Builder builder = new AlertDialog.Builder(activity); 
    builder.setMessage("There is newer version of this application available, click OK to update now?").setPositiveButton("OK" + 
     "", new DialogInterface.OnClickListener() { 

     public void onClick(DialogInterface dialog, int id) { 

      Log.e("onClick", "AlertUpdate"); 
      Intent marketIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("url")); 
      marketIntent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET|Intent.FLAG_ACTIVITY_MULTIPLE_TASK); 
      app_context. startActivity(marketIntent); 
     } 
    }).setNegativeButton("Remind Later", new DialogInterface.OnClickListener() { 

     public void onClick(DialogInterface dialog, int id) { 

      // User cancelled the dialog 
     } 

    }).setOnKeyListener(new OnKeyListener() { 

     @Override 
     public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) { 
       if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_UP) { 
        return false; 
       } 

       return true; 
      } 
     }); 
    builder.create().show(); 
} 

錯誤日誌

04-03 09:04:44.007: E/AndroidRuntime(2249): java.lang.RuntimeException: Unable to start activity ComponentInfo{gsip.webgalaxy/gsip.webgalaxy.ui.MainActivity}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread.access$800(ActivityThread.java:135) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.os.Handler.dispatchMessage(Handler.java:102) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.os.Looper.loop(Looper.java:136) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread.main(ActivityThread.java:5017) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at java.lang.reflect.Method.invoke(Method.java:515) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at dalvik.system.NativeStart.main(Native Method) 
04-03 09:04:44.007: E/AndroidRuntime(2249): Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.view.ViewRootImpl.setView(ViewRootImpl.java:540) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:259) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.Dialog.show(Dialog.java:286) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at gsip.webgalaxy.ui.Communicator.getversion(Communicator.java:226) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at gsip.webgalaxy.ui.MainActivity.onCreate(MainActivity.java:460) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.Activity.performCreate(Activity.java:5231) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 
04-03 09:04:44.007: E/AndroidRuntime(2249):  ... 11 more 
04-03 09:09:44.177: I/Process(2249): Sending signal. PID: 2249 SIG: 9 

生成錯誤

Answer 1

對於對話框，您需要一個ActivityContext。如果您是從非活動課展示它，請將參考文獻傳遞給Activity作爲參數。

Answer 2

其中一種可能性是在啓動其他Activity時指定一些額外功能，然後攔截目標Activity中的這些額外功能並相應地顯示AlertDialog。

事情是這樣的......

來源Activity：

Intent intent = new Intent(this, TargetActivity.class); 
    Bundle bundle = new Bundle(); 
    bundle.putInt("alert_icon_res_id", android.R.drawable.ic_dialog_info); 
    bundle.putString("alert_title", "Some Title"); 
    bundle.putString("alert_message", "Some message"); 
    intent.putExtras(bundle); 
    startActivity(intent); 

目標Activity：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    Bundle b = getIntent().getExtras(); 
    if (b != null && b.containsKey("alert_icon_res_id")) { 
    int icon = b.getInt("alert_icon_res_id"); 
    int title = b.getString("alert_title"); 
    int message = b.getString("alert_message"); 

    new AlertDialog.Builder(this).setIcon(icon) 
     .setTitle(title).setMessage(message) 
     .setPositiveButton(R.string.edit_dialog_ok, new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int which) { 
      dialog.dismiss(); 
     } 
     }).create().show()); 
    } 
}