调用 onSocket:didReadData:withTag 时 CocoaAsyncSockets 似乎失败了

Question

由于某种原因，当我尝试调用 CocoaAsyncSocket 的 onSocket:didReadData:withTag 方法时，它失败并且不显示读取的数据。

appDelegate：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{   
    NSError *error = nil;
    if (![socket connectToHost:@"199.5.83.63" onPort:11005 error:&error]) 
    {
        NSLog(@"Error connecting: %@", error);
    }

    [socket readDataWithTimeout:10 tag:1];

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    self.viewController = [[[tekMatrixViewController alloc] initWithNibName:@"tekMatrixViewController" bundle:nil] autorelease];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

这是我在 CocoaAsyncSocket 库中的方法：

- (void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
    NSData *strData = [data subdataWithRange:NSMakeRange(0, [data length])];
    NSString *msg = [[NSString alloc] initWithData:strData encoding:NSUTF8StringEncoding];
    NSLog(@"RX length: %d", [data length]);
    if(msg)
    {
        NSLog(@"RX:%@",msg);
    }
    else 
    {
        NSLog(@"Fail");
    }    
}

- (void)onSocket:(AsyncSocket *)sock willDisconnectWithError:(NSError *)err
{
    NSLog(@"error - disconnecting");
    //start reconnecting procedure here...
}

- (void)onSocketDidDisconnect:(AsyncSocket *)sock
{
    NSLog(@"disconnected");
}

- (void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
    NSLog(@"connected");
}

当我在模拟器中运行我的应用程序时，我的输出日志是这样输出的：

2012-06-08 13:17:30.808 tekMatrix[2793:f803] connected
2012-06-08 13:17:30.815 tekMatrix[2793:f803] RX length: 8
2012-06-08 13:17:30.816 tekMatrix[2793:f803] Fail

• onSocket:didConnectToHost:port 被调用，NSLog 吐出“已连接”。
• onSocket:didReadData:withTag 被调用，NSLog 吐出“RX length: 8”。
• 同样在 onSocket:didReadData:withTag 中，NSLog 吐出“失败”。

如果我错了，请纠正我，但“msg”不应该包含从服务器读取的数据的值？看起来 Data Read 知道它期望的数据长度为 8，但数据似乎没有存储到字符串中。我对 iOS 非常陌生，尤其是套接字编程，所以这对我来说是全新的。对此主题的任何帮助将不胜感激。

谢谢！

Answer 1

我相信，服务器正在传送不是 UTF-8 编码的数据。
请尝试

NSString *msg = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];

_{并删除此行：NSData *strData = [data subdataWithRange:NSMakeRange(0, [data length])];}

如果这没有帮助，here are some more encodings 试试：

enum {
   NSASCIIStringEncoding = 1,
   NSNEXTSTEPStringEncoding = 2,
   NSJapaneseEUCStringEncoding = 3,
   NSUTF8StringEncoding = 4,
   NSISOLatin1StringEncoding = 5,
   NSSymbolStringEncoding = 6,
   NSNonLossyASCIIStringEncoding = 7,
   NSShiftJISStringEncoding = 8,
   NSISOLatin2StringEncoding = 9,
   NSUnicodeStringEncoding = 10,
   NSWindowsCP1251StringEncoding = 11,
   NSWindowsCP1252StringEncoding = 12,
   NSWindowsCP1253StringEncoding = 13,
   NSWindowsCP1254StringEncoding = 14,
   NSWindowsCP1250StringEncoding = 15,
   NSISO2022JPStringEncoding = 21,
   NSMacOSRomanStringEncoding = 30,
   NSUTF16StringEncoding = NSUnicodeStringEncoding,
   NSUTF16BigEndianStringEncoding = 0x90000100,
   NSUTF16LittleEndianStringEncoding = 0x94000100,
   NSUTF32StringEncoding = 0x8c000100,
   NSUTF32BigEndianStringEncoding = 0x98000100,
   NSUTF32LittleEndianStringEncoding = 0x9c000100,
   NSProprietaryStringEncoding = 65536
};

NSISOLatin1StringEncoding 也很常见。