如何弹出一个Android对话框

Question

I have the following code which doesn't work, what should I do to debug it?

I created a new android 2.2 project, added a button and the button has:

    android:onClick="Test"

the Test() function is here:

public void Test(View view) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this.getApplicationContext());
    builder.setTitle("Title");
    builder.setMessage("Message");
    builder.setPositiveButton("ok", new OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1)
            {
                // TODO Auto-generated method stub
                arg0.dismiss();
            }});
    builder.setCancelable(false);
    builder.create().show();
}

When it's triggered, the show() will cause this exception:

Thread [<1> main] (Suspended (exception WindowManager$BadTokenException))   
    <VM does not provide monitor information>   
    AlertDialog(Dialog).show() line: 245    
    MainActivity.Test(View) line: 39    
    Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
    Method.invoke(Object, Object...) line: 521  
    View$1.onClick(View) line: 2067 
    Button(View).performClick() line: 2408  
    View$PerformClick.run() line: 8817  
    ViewRoot(Handler).handleCallback(Message) line: 587 
    ViewRoot(Handler).dispatchMessage(Message) line: 92 
    Looper.loop() line: 143 
    ActivityThread.main(String[]) line: 4914    
    Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
    Method.invoke(Object, Object...) line: 521  
    ZygoteInit$MethodAndArgsCaller.run() line: 868  
    ZygoteInit.main(String[]) line: 626 
    NativeStart.main(String[]) line: not available [native method]

BTW There are some other things I tried: DialogFragment doesn't show up

Answer 1

remove android:onClick="Test" from your layout.xml and use

Button btn = (Button) view.findViewById(R.id.your_btn);
btn.setOnClickListener(new OnClickListener() {
test();
});

instead

btw. you should't use getApplicationContext() ---> use this

Answer 2

That is a unique LogCat, you rewrote that by hand didn't you... :) Next time you can highlight the LogCat and press Ctrl + C

Anyway, I see the BadTokenException. Change:

new AlertDialog.Builder(this.getApplicationContext());

To:

new AlertDialog.Builder(MyActivity.this);