ios中UIAlertView控件的使用，如何确定点击按钮的方式

- (void)initCheckVersionWithData:(NSData *)data 

{

    NSData *xmlData = data;

    NSString *result = [[NSString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding]; 

    NSLog(@"result:%@",result);

    

    GetCheckVersion *parser = [[GetCheckVersion alloc] initWithXMLData:xmlData];

    [parser parse];

    NSString *status = parser.tempResult.status;

    NSLog(@"status:%@",status);

    if ([@"201" isEqualToString:status]) {

        NSLog(@"版本不需要更新，OK");

    }

    else if ([@"200" isEqualToString:status]) {

        UIAlertView * alertview = [[UIAlertView alloc] initWithTitle:@"提示" message:@"是否更新版本" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];

        [alertview show];

        [alertview release];

        alertview = nil;

    }

}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex

{

    NSString *msg = [[NSString alloc] initWithFormat:@"您点击的是第%d个按钮!",buttonIndex];

    NSLog(@"msg:%@",msg);

    

    if (buttonIndex == 0) {

        return;

    }else if(buttonIndex == 1){

        [httpClient getUpdateVersion];

    }

}