php - 如何在不收到错误响应的情况下与 ObjectiveC 中的服务器进行交互？

Question

这是我的第一个问题:)

我真的需要一些服务器和 PHP 方面的帮助。这是问题:

我有一个 NSMutableURLRequest 与这样的 php 文件交互:

    NSInteger userID = 4;

    NSString * logInString = [NSString stringWithFormat:@"id=%i&mode=HARD", userID];
    NSData * logInData = [logInString dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

    NSString *postLength = [NSString stringWithFormat:@"%d", [logInData length]];

    NSMutableURLRequest * logInRequest = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://myurl.lol/login.php"]];
    [logInRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [logInRequest setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [logInRequest setHTTPMethod:@"POST"];
    [logInRequest setHTTPBody:logInData];

    [NSURLConnection sendAsynchronousRequest:logInRequest queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
        if ([data length] >0 && error == nil) {
            NSString * responseString = [NSString stringWithUTF8String:data.bytes];
            NSLog(@"%@", responseString);
            [self performSelectorOnMainThread:@selector(responseWasReceived:) withObject:responseString waitUntilDone:YES];
        }
        else if ([data length] == 0 && error == nil) {
            [self performSelectorOnMainThread:@selector(didNotReceivedResponse) withObject:nil waitUntilDone:YES];
        }
        else if (error != nil) {
            [self performSelectorOnMainThread:@selector(errorDidOccurred) withObject:nil waitUntilDone:YES];

            NSLog(@"Error = %@", error);
        }
    }];

我的 PHP 是这样的:

include("database.php");

if ($_REQUEST['mode'] == 'HARD') {
    $query = mysql_query('SELECT COUNT(*) as total FROM users WHERE id = "' . $_REQUEST['id'] . '"');

    $fetch_username = mysql_fetch_object($query);
    $usernames_coincidences = $fetch_username -> total;

    if ($usernames_coincidences == 1) {
        exit("ACCESS GRANTED");
    } else {
        exit("USER DOES NOT EXIST");
    }
}

我应该收到“ACCESS GRANTED”字符串，有时它会发生，但有时我会收到错误的响应，如“ACCESS GRANTED¿”或“ACCESS GRANTEDOL”。

有什么问题？您认为我应该在方法中使用同步请求并使用 performSelector:inBackground: 执行它吗？

Answer 1

您正在尝试使用不一定以 NULL 结尾的原始数据构造 responseString。

取而代之的是:

[NSString stringWithUTF8String:data.bytes];

改用这个:

[[NSString alloc] initWithBytes:data.bytes length:data.length encoding:NSUTF8StringEncoding];

请注意，我没有考虑您是否使用 ARC。您的原始调用产生了一个自动释放的值；我的没有；确保不会漏水。