AlertDialog对话框

举例：

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btn = (Button)findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				showDialog(DIALOG1);
			}
		});
}
@Override
	protected Dialog onCreateDialog(int id) {
		switch (id) {
		case DIALOG1:
			return dialog1();

		default:
			break;
		}
		return super.onCreateDialog(id);
}
Dialog dialog1(){
AlertDialog.Builder bul = 
new AlertDialog.Builder(DialogActivity.this);
		bul.setTitle("测试对话框");
		bul.setMessage("测试对话框内容");
bul.setPositiveButton("确定", 
new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				setTitle("单击对话框确定按钮");
			}
		});
bul.setNeutralButton("进入", 
new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				setTitle("单击对话框进入按钮");
			}
		});
bul.setNegativeButton("取消", 
new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				setTitle("单击对话框取消按钮");
			}
		});
		return bul.create();
	}