iOS：outputStream不会保持打开

Question

好吧，我正在实现NSOutput和Input Streams。当它们被初始化时，流打开并连接到我的PC上运行的TCPServer，但在初始化函数之外似乎关闭一次，或者流可能没有正确存储。我不太清楚，所以任何帮助是极大的赞赏

在我的.h文件：

@interface AVCamViewController : UIViewController <UIImagePickerControllerDelegate,UINavigationControllerDelegate, NSStreamDelegate> { 
    NSOutputStream *outputStream; 
    NSInputStream *inputStream; 
} 

@property (retain) NSInputStream *inputStream; 
@property (retain) NSOutputStream *outputStream; 

在我的.m文件：

@synthesize inputStream, outputStream; 

    -(void)sendaResponse 
    { 
     NSString *response = [NSString stringWithFormat:@"Hello from Ipad Simulator"]; 
     NSData *data = [[NSData alloc] initWithData:[response dataUsingEncoding:NSASCIIStringEncoding]]; 
     [outputStream write:[data bytes] maxLength:[data length]]; 
     NSLog(@"%u", outputStream.streamStatus); 
    } 

    -(void)initNetworkCommunication 
    { 
     CFReadStreamRef readStream; 
     CFWriteStreamRef writeStream; 
     CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)@"10.9.100.122", 80, &readStream, &writeStream); 

     NSInputStream *inputStream = (NSInputStream *) readStream; 
     NSOutputStream *outputStream = (NSOutputStream *) writeStream; 

     [inputStream setDelegate:self]; 
     [outputStream setDelegate:self]; 
     [inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
     [outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
     [inputStream open]; 
     [outputStream open]; 


     NSLog(@"%u and %u", inputStream.streamStatus, outputStream.streamStatus); 
     NSString *response = [NSString stringWithFormat:@"Hello from Mikes Ipad Simulator"]; 
     NSData *data = [[NSData alloc] initWithData:[response dataUsingEncoding:NSASCIIStringEncoding]]; 
     [outputStream write:[data bytes] maxLength:[data length]]; 
     NSLog(@"%u", outputStream.streamStatus); 
    } 

    -(void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode 
    { 
     switch (eventCode) { 
      case NSStreamEventOpenCompleted: 
       NSLog(@"Stream Opened %u", outputStream.streamStatus); 
       break; 

      case NSStreamEventHasBytesAvailable: 
       if(aStream == inputStream) 
       { 
        uint8_t buffer [1024]; 
        int len; 

        while ([inputStream hasBytesAvailable]) 
        { 
         len = [inputStream read:buffer maxLength:sizeof(buffer)]; 
         if(len>0) 
         { 
          NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding]; 

          if(nil != output) 
          { 
           NSLog(@"Server said: %@", output); 
          } 
         } 
        } 
       } 
       break; 

      case NSStreamEventErrorOccurred: 
       NSLog(@"Can not connect to the host!"); 
       break; 

      case NSStreamEventEndEncountered: 
       if(aStream == inputStream) 
        NSLog(@"Ending input stream"); 
       if(aStream == outputStream) 
        NSLog(@"Ending output stream"); 

       [aStream close]; 
       [aStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
       [aStream release]; 
       aStream = nil; 
       break; 

      default: 
       break; 
     } 
    } 

在initNetworkConnection模拟器连接到我TCPServer并打开一个连接（streamstatus = 2）。接收到消息“Ipad Simulator Hello”。 但是，然后我有一个按钮点击调用“sendaResponse”方法，然后streamstatus = 0和“outputstream”似乎没有被初始化。我只是没有正确保留变量？

Answer 1

我假设你正在使用ARC。 中删除此代码：

{ 
NSOutputStream *outputStream; 
NSInputStream *inputStream; 
} 

@synthesize inputStream, outputStream; 

这只是迷惑你的属性和实例变量之间。并且它的结果是你直接设置实例变量，并且你的流实例被ARC解除分配。

取而代之，一旦您删除了上面的代码，请使用self.inputStream和self.outputStream访问流。这将允许属性正常工作，并确保您配置的“保留”规范得到遵守。

您的原始代码也可能只是没有尝试设置属性... 你的配置应该是：

NSInputStream *inputStream = (NSInputStream *) readStream; 
    NSOutputStream *outputStream = (NSOutputStream *) writeStream; 

    [inputStream setDelegate:self]; 
    [outputStream setDelegate:self]; 
    [inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
    [outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
    [inputStream open]; 
    [outputStream open]; 

self.inputStream = inputStream; 
self.outputStream = outputStream; 

然后，更改属性：

@property (strong) NSInputStream *inputStream; 
@property (strong) NSOutputStream *outputStream;