如何创建对话框

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);//2.设置标题和内容builder.setTitle("退出程序");builder.setMessage("你确定要退出吗？");//2.1 添加按钮builder.setPositiveButton("确定", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubToast.makeText(getApplicationContext(), "正在退出……", 200).show();}} );builder.setNegativeButton("取消", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubToast.makeText(getApplicationContext(), "正在退出……", 200).show();}});//3.设置好对话框编译者之后，创建对话框AlertDialog dialog = builder.create();//4.显示对话框dialog.show();[