Question

我在ListView中有一个ContextMenu，它可以选择从ListView中删除一个项目。因此，当用户从ContextMenu中选择DELETE时，我想显示一个AlertDialog，要求确认此删除。

但是当在onMenuItemSelected（..）中调用AlertDialog.show（）时，它不会显示Dialog。此对话框仅在onMenuItemSeletect（..）

的“return true”后显示

    @Override
    public boolean onMenuItemSelected(int featureId, MenuItem item) {
    switch (item.getItemId()) {

    //0: for OPEN of R.array.context_menu_categories
    case 0:

        break;

    //2: DELETE
    case 2:

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

         // Setting Dialog Title
        alertDialog.setTitle("Delete...");

        // Setting Dialog Message
        alertDialog.setMessage("Do you want to delete this?");


        // Setting Positive "Yes" Button
        alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            // User pressed YES button. Write Logic Here
            Toast.makeText(getApplicationContext(), "You clicked on YES", Toast.LENGTH_SHORT).show();
            }
        });

        // Setting Negative "NO" Button
        alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            // User pressed No button. Write Logic Here
            Toast.makeText(getApplicationContext(), "You clicked on NO", Toast.LENGTH_SHORT).show();
            }
        });

        alertDialog.show();

        break;

    default:
    break;
}

  return true;
}

Answer 1

这就是Android的工作原理。在应用程序重绘自身之前，图形元素不会出现，这发生在Android事件循环中。要返回事件循环，您必须退出Android调用的函数。在此函数返回之前无法显示它。

从ContextMenu显示AlertDialog

1 个答案: