Andorid系统默认Dialog的使用

AlertDialog.Builder builder = new Builder(MyWeiboZhengwen.this);
builder.setMessage("是否删除该动态？");
builder.setTitle("注意");
builder.setPositiveButton("确认", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
if (AndroidHttpClient.isNetworkAvailable(MyWeiboZhengwen.this)) {
DeleteWeiboTask delete = new DeleteWeiboTask();
delete.execute();
}
else {
toast.setText(R.string.network_not_avaliable);
toast.show();
}
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.dismiss();
}
});
builder.show();