android 常用功能组件——确认退出程序Dialog

当点击返回按钮，或者退出按钮时，提示用户重新确定是否要退出当前Activity：

@Override
public void onBackPressed() {
// TODO Auto-generated method stub
AlertDialog.Builder builder = new Builder(UpnpMainAct.this);
builder.setMessage("确认退出程序？");
builder.setTitle("提示");
builder.setPositiveButton("确认", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {

finish();
}
});
builder.setNegativeButton("取消", null);

builder.create().show();
}