Android 开发——在 Tab Activity 中显示的 AlertDialog

Question

我无法在选项卡 Activity 中显示警告对话框。每次我尝试显示警报对话框时，我的应用程序都会强制关闭。我的代码如下:

public class TablesActivity extends ListActivity {

final int INFO_ID = 0;
final int STATUS_ID = 1;
AlertDialog alert = null;

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

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Are you sure you want to mark table as dirty?")
            .setCancelable(false)
            .setPositiveButton("Yes",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            Toast.makeText(getApplicationContext(), "Table Marked Dirty",
                                    Toast.LENGTH_LONG).show();
                        }
                    })
            .setNegativeButton("No", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
                }
            });

    alert = builder.create();

    setListAdapter(new ArrayAdapter<String>(this, R.layout.history,
            TABLES));

    ListView lv = getListView();
    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // When clicked, show a toast with the TextView text
            Toast.makeText(getApplicationContext(),
                    ((TextView) view).getText(), Toast.LENGTH_LONG).show();
        }
    });

    lv.setOnItemLongClickListener(new OnItemLongClickListener() {

        @Override
        public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {


            alert.show();
            // TODO Auto-generated method stub
            return true;
        }

    });
}

static final String[] TABLES = new String[] { "Table 1", "Table 2",
        "Table 3", "Table 4", "Table 5", "Table 6", "Table 7", "Table 8",
        "Table 9", "Table 10", "Table 11", "Table 12", "Table 13"

};

}

问题出现在我尝试执行 dialog.show() 时，而不是其他任何地方。我收到以下 logcat 错误:

04-16 17:25:15.519: ERROR/AndroidRuntime(311): android.view.WindowManager$BadTokenException: 无法添加窗口—— token android.app.LocalActivityManager$LocalActivityRecord@44f08320 无效；你的 Activity 在运行吗？

错误源自 dialog.show() 行。我不确定到底该做什么。在由 TabHost 生成的 ActivityGroup 较早启动之后，该 Activity 正在运行。

关于我可以做些什么来解决这个问题有什么想法吗？我束手无策。

Answer 1

请使用

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

代替

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