Question

我正在尝试在后台线程中运行我的整个网络内容，因为当服务器无法访问时（即），它当前会阻塞主线程。

我目前正通过以下代码创建网络连接。有一种简单的方法可以在新的后台线程中运行它吗？

如何将收到的消息丢回主线程？我该如何通过后台线程发送消息？

CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)ipAdress, port, &readStream, &writeStream);
inputStream = (__bridge NSInputStream *)readStream;
outputStream = (__bridge NSOutputStream *)writeStream;
[inputStream setDelegate:self];
[outputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[inputStream open];
[outputStream open];

Answer 1

here是一个完全按照你所说的做的教程。虽然它更侧重于音频流，但原则完全相同（即产生工作线程，让它与父线程等进行对话等）。

这个想法很简单..您创建一个新线程并让它处理流式传输工作，然后使用属于您刚刚创建的线程的运行循环来安排流式读取器。当ceratain事件发生时（即你获得一些数据，连接超时等），流将有回调。在回调方法中，你可以警告或与mainthread（处理UI的线程）通信

以下是一些代码指向正确的方向，但是如果您从上面的教程中下载code并继续操作......那么您将获得它：

// create a new thread
internalThread =
                [[NSThread alloc]
                    initWithTarget:self
                    selector:@selector(startInternal)
                    object:nil];
            [internalThread start];

// creating a stream inside the 'startInternal' thread*
stream = CFReadStreamCreateForHTTPRequest(NULL, message);

// open stream
CFReadStreamOpen(stream) 

// set callback functions
// ie say: if there are bites available in the stream, fire a callback etc
CFStreamClientContext context = {0, self, NULL, NULL, NULL};
CFReadStreamSetClient(
        stream,
        kCFStreamEventHasBytesAvailable | kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered,
        ASReadStreamCallBack,
        &context);

// schedule stream in current thread runloop, so that we DON'T block the mainthread
CFReadStreamScheduleWithRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);

// create the callback function to handle reading from stream
// NOTE: see where else in the code this function is named (ie CFReadStreamSetClient)
static void ASReadStreamCallBack
(
   CFReadStreamRef aStream,
   CFStreamEventType eventType,
   void* inClientInfo
)
{
    //handle events you registered above
    // ie
    if (eventType == kCFStreamEventHasBytesAvailable) {
        // handle network data here..
        ..
        // if something goes wrong, create an alert and run it through the main thread:
        UIAlertView *alert = [
            [[UIAlertView alloc]
                initWithTitle:title
                message:message
                delegate:self
                cancelButtonTitle:NSLocalizedString(@"OK", @"")
                otherButtonTitles: nil]
            autorelease];
            [alert
                performSelector:@selector(show)
                onThread:[NSThread mainThread]
                withObject:nil
                waitUntilDone:NO];        
    }          
}

在后台线程中运行NSStream

1 个答案: