基本上我在我的应用程序中使用 ActivityGroup。我有这种情况:
我有活动 A 的 Tabhost。
Activity A 创建 childActivity B。
A ---> B
startChildActivity("CollectionList", new Intent(this,MyCollectionList.class));
活动 B 创建 3 个子活动 C、D。
B ---> C (childActivity of B)
startChildActivity("Recommended", new Intent(MyCollectionList.this,Recommended.class));
B ---> D (childActivity of B)
startChildActivity("ExpectSoon", new Intent(MyCollectionList.this,ExpectSoon.class));
B 也创建了另一个 childActivity,将其命名为 E。
B ---> E
Intent previewMessage = new Intent(getParent(), MyCollectionId.class);
TabGroupActivity parentActivity = (TabGroupActivity)getParent();
parentActivity.startChildActivity("MyCollectionId", previewMessage);
所以基本上活动 C 和 D 也可以启动活动 E,其中:
Intent previewMessage = new Intent(getParent(), MyCollectionId.class);
TabGroupActivity parentActivity = (TabGroupActivity)getParent();
parentActivity.startChildActivity("MyCollectionId", previewMessage);
我已经覆盖了 onBackPressed 方法,所以我可以控制后退按钮。它看起来像这样:
private ArrayList<String> mIdList;
@Override
public void onBackPressed () {
int length = mIdList.size();
if ( length >=1) {
Activity current = getLocalActivityManager().getActivity(mIdList.get(length-1));
current.finish();
}
}
所以我的问题是,当我在活动 E 中并按下后退按钮时,我的应用程序关闭。我遇到的另一个问题是活动 E 中的警报对话框。
Button deactivate = (Button) findViewById(R.id.deactivate);
deactivate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
new AlertDialog.Builder( getParent() )
.setTitle( "Warning" )
.setMessage( "The collection will be removed completely from the device.You can reactivate it later again.This operation requires internet connection." )
.setPositiveButton( "Go ahead", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d("AlertDialog", "Positive");
}
})
.setNegativeButton( "Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d("AlertDialog","Negative");
}
})
.show();
}
});
当我从 A 启动活动 E 时,当我单击按钮时,将显示警报对话框,一切正常。但是当我从 C 或 D 启动活动 E 时,它会抛出异常:
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): FATAL EXCEPTION: main
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): android.view.WindowManager$BadTokenException: Unable to add window -- token android.app.LocalActivityManager$LocalActivityRecord@4630ea20 is not valid; is your activity running?
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.ViewRoot.setView(ViewRoot.java:509)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.Window$LocalWindowManager.addView(Window.java:424)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.app.Dialog.show(Dialog.java:241)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.app.AlertDialog$Builder.show(AlertDialog.java:802)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at com.stampii.stampii.mystampii.MyCollectionId$4.onClick(MyCollectionId.java:75)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.View.performClick(View.java:2408)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.view.View$PerformClick.run(View.java:8817)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.os.Handler.handleCallback(Handler.java:587)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.os.Handler.dispatchMessage(Handler.java:92)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.os.Looper.loop(Looper.java:144)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at android.app.ActivityThread.main(ActivityThread.java:4937)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at java.lang.reflect.Method.invokeNative(Native Method)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at java.lang.reflect.Method.invoke(Method.java:521)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-15 15:48:22.819: ERROR/AndroidRuntime(32440): at dalvik.system.NativeStart.main(Native Method)
编辑:
我的 startChildActivity 看起来像这样:
public void startChildActivity(String Id, Intent intent) {
Window window = getLocalActivityManager().startActivity(Id,intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
if (window != null) {
mIdList.add(Id);
setContentView(window.getDecorView());
}
}
最新的 LogCat,在 ActivityE 中使用 Recommended.parentActivity 时:
new AlertDialog.Builder( Recommended.parentActivity )
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): FATAL EXCEPTION: main
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): java.lang.NullPointerException
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at com.android.internal.app.AlertController$AlertParams.<init>(AlertController.java:743)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.app.AlertDialog$Builder.<init>(AlertDialog.java:273)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at com.stampii.stampii.mystampii.MyCollectionId$4.onClick(MyCollectionId.java:62)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.view.View.performClick(View.java:2408)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.view.View$PerformClick.run(View.java:8817)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.os.Handler.handleCallback(Handler.java:587)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.os.Handler.dispatchMessage(Handler.java:92)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.os.Looper.loop(Looper.java:144)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at android.app.ActivityThread.main(ActivityThread.java:4937)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at java.lang.reflect.Method.invokeNative(Native Method)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at java.lang.reflect.Method.invoke(Method.java:521)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-15 16:33:53.509: ERROR/AndroidRuntime(1967): at dalvik.system.NativeStart.main(Native Method)