1、在layout中新增按鈕

2、在MainActivity中新增以下函式

    public void showDialog(View view){
        AlertDialog.Builder builder=new AlertDialog.Builder(this);
        builder.setTitle("標題");
        builder.setMessage("提示內容");
        builder.setPositiveButton("我知道了", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });
        AlertDialog dialog=builder.create();
        dialog.show();
    }
 

 3、在按鈕的OnCIick事件繫結以上函式

顯示效果