Android AlertDialog框WindowManager $ BadTokenException问题

Question

我使用以下代码作为上下文菜单,然后如果用户选择删除,将出现对话按摩.

infos.setOnCreateContextMenuListener(new OnCreateContextMenuListener(){
            //@Override
            public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
                menu.setHeaderTitle("Context Menu");
                menu.add(0, CONTEXT_EDIT, 0, "Edit Item");
                menu.add(0, CONTEXT_DELETE, 1, "Delete Item");
            }
});

public boolean onContextItemSelected(MenuItem item) {

        AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
        final Long _id = menuInfo.id;
        //selected_row = menuInfo.position;

        // To get the id of the clicked item in the list use menuInfo.id
        switch (item.getItemId()) {
            case CONTEXT_EDIT:
                addEditRes(_id);
                break;
            case CONTEXT_DELETE:
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setMessage("Are you sure you want to delete?")
                       .setCancelable(false)
                       .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                           public void onClick(DialogInterface dialog, int id) {
                               infoDataHelper.deleteRes(_id);  
                               model = infoDataHelper.getCursor(addType);
                               adapter.changeCursor(model);
                           }
                       })
                       .setNegativeButton("No", new DialogInterface.OnClickListener() {
                           public void onClick(DialogInterface dialog, int id) {
                                dialog.cancel();
                           }
                       });
                AlertDialog alert = builder.create();   
                alert.show();
                break;
            default:
                return super.onContextItemSelected(item);

        }
        adapter.notifyDataSetChanged();
        return true;
}

但是,一旦我选择删除,它就会出现以下错误.

android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application

我的代码有什么问题？

Answer 1

我相信问题可能就在这条线上:

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

尝试将其修改为:

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

用您的活动名称替换MyActivityName.

这样可以解决错误吗？

Answer 2

它应该是AlertDialog.Builder builder = new AlertDialog.Builder(this.getParent());

因为活动是在另一个tabactivity内的tabactivity.

Answer 3

我得到了同样的错误.我变了

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

至

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

它的工作正常.谢谢.