AlertDialog，ProgressDialog

AlertDialog.Builder dialog=new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("这是一个dialog");
dialog.setMessage("你真的真的确定要弃我而去吗！！！");
dialog.setCancelable(false);//false按返回键不能退出。
dialog.setPositiveButton("确定",new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub
ProgressDialog progressdialog=new ProgressDialog(MainActivity.this);
progressdialog.setTitle("这是一个progressdialog");
progressdialog.setMessage("loading......");
progressdialog.setCancelable(true);
progressdialog.show();
}
});
dialog.setNegativeButton("取消", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub
finish();
}
});
dialog.show();