无法从ActivityGroup中的ListActivity中显示AlertDialog

Question

我想在单击ListActivity中的项目时显示AlertDialog.我的应用程序在TabActivity的选项卡下显示ListActivity,并且AlertDialog显示没有问题.ListActivity(称为FavouritesActivity)非常直接来自Android文档,具有以下设置:

    lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {

                //... code to set the strings station, number, route, and direction

                FavouritesActivity.this.confirmSend(position);
            }
        });

然后

public void confirmSend(final int position) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Are you sure?")
        .setCancelable(true)
        .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    //... some code to run here                                                              
                }
            })
        .setNegativeButton("No", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
                }
            });
    AlertDialog alert = builder.create();
    alert.show();
}

但是,在TabActivity的第二个选项卡中,我有一个ActivityGroup,它使用LocalActivityManager来启动另一个ListActivity,就像这样(再次,在联机选项卡下的嵌套列表教程中几乎没有变化):

public class MyGroupActivity extends ActivityGroup {

// Keep this in a static variable to make it accessible for all the nesten activities, lets them manipulate the view                                      
public static MyGroupActivity group;

// Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.            
private ArrayList<View> history;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.history = new ArrayList<View>();
    group = this;

    // Start the root activity withing the group and get its view                                                                                         
    View view = getLocalActivityManager().startActivity("FirstListActivity", new
                                                        Intent(this,FirstListActivity.class)
                                                        .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))
        .getDecorView();

    // Replace the view of this ActivityGroup                                                                                                             
    replaceView(view);

}

public void replaceView(View v) {
    // Changes this Groups View to the new View.                                                                                                          
    setContentView(v);
}

这里的FirstListActivity是ListActivity,它是系列中的第一个.用户选择一个项目,并显示另一个ListActivity,代码如下:

    lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                Intent intent = new Intent();
                intent.setClass(FirstListActivity.this, TheNextListActivity.class);                                                                                                                

                // Create View using the Group Activity's LocalActivityManager                                                                            
                View newview = MyGroupActivity.group.getLocalActivityManager()
                    .startActivity("show_routes", intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))
                    .getDecorView();
                // And replace the view                                                                                                                   
                MyGroupActivity.group.replaceView(newview);
            }
        });

本系列中的最后一个ListActivity与onItemClick监听器和关联的confirmSend函数完全相同,作为我展示的第一个ListActivity示例(可以工作的那个),但是现在当用户点击某个项目时,AlertDialog无法显示并且应用程序停止意外地,使用此调试输出:

W/WindowManager(  570): Attempted to add application window with unknown token android.os.BinderProxy@4373af30.  Aborting.
D/AndroidRuntime( 1953): Shutting down VM
W/dalvikvm( 1953): threadid=3: thread exiting with uncaught exception (group=0x4000fe70)
E/AndroidRuntime( 1953): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime( 1953): android.view.WindowManager$BadTokenException: Unable to add window -- token android.app.LocalActivityManager$LocalActivityRecord@43750f98 is not valid; is your activity running?
E/AndroidRuntime( 1953):    at android.view.ViewRoot.setView(ViewRoot.java:425)
E/AndroidRuntime( 1953):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:178)
E/AndroidRuntime( 1953):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
E/AndroidRuntime( 1953):    at android.view.Window$LocalWindowManager.addView(Window.java:392)
E/AndroidRuntime( 1953):    at android.app.Dialog.show(Dialog.java:231)
E/AndroidRuntime( 1953):    at com.ttcsms.LastListActivity.confirmSend(LastListActivity.java:119)
E/AndroidRuntime( 1953):    at com.ttcsms.LastListActivity$1.onItemClick(LastListActivity.java:66)
E/AndroidRuntime( 1953):    at android.widget.AdapterView.performItemClick(AdapterView.java:283)
E/AndroidRuntime( 1953):    at android.widget.ListView.performItemClick(ListView.java:3132)
E/AndroidRuntime( 1953):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:1620)
E/AndroidRuntime( 1953):    at android.os.Handler.handleCallback(Handler.java:587)
E/AndroidRuntime( 1953):    at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime( 1953):    at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime( 1953):    at android.app.ActivityThread.main(ActivityThread.java:3948)
E/AndroidRuntime( 1953):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 1953):    at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime( 1953):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
E/AndroidRuntime( 1953):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
E/AndroidRuntime( 1953):    at dalvik.system.NativeStart.main(Native Method)
I/Process (  570): Sending signal. PID: 1953 SIG: 3
I/dalvikvm( 1953): threadid=7: reacting to signal 3
I/dalvikvm( 1953): Wrote stack trace to '/data/anr/traces.txt'
I/Process ( 1953): Sending signal. PID: 1953 SIG: 9
I/ActivityManager(  570): Process com.ttcsms (pid 1953) has died.

这两个导致此失败的AlertDialog路由有什么区别？它似乎与AlertDialog.Building(this)位有关.在ActivityGroup中,它会得到错误的上下文或其他内容.我在网上发现的这个错误的每个例子都是通过在"this"和"getApplicationContext()"之间进行更改来解决的,但在这种情况下,这些都不起作用.我尝试了其他变化来获取上下文,但我随意猜测,我认为最好在这里征求意见.我应该通过什么背景,或者还有什么错？

Answer 1

得到它了!实际上这是一个Android上下文问题.

排队:

AlertDialog.Builder builder = new AlertDialog.Builder(this);

而不是这个,你应该通过语境TabActivity,可见/主要活动的情况下被传递到显示活动中的任何弹出窗口.

那么简单的解决方案:

1. 存储TabActivity的上下文以供稍后在弹出窗口中使用.
2. 在弹出代码中传递TabActivity Context而不是此.

希望这可以帮助.欢呼:)

Answer 2

最后按照你的方法解决了我的问题.我在这里提供一些细节

为Tabactivity类创建一个上下文,如下所示.

"public static MyTabactivity context;"

在MyTabactivity的onCreate方法中指定"context = this".
然后在警报框中使用MyTabactivity.context,如下所示.

"AlertDialog.Builder adb = new AlertDialog.Builder(MyTabactivity.context);"

我希望这个能帮上忙.....

Answer 3

为了使它变得相当简单,onCreate你可以直接传递getParent()上下文,而不是定义上下文变量并设置它AlertDialog.