ASIHTTPRequest占用主线程问题解决

ASIHTTPRequest是个很易用的iOS / Mac OS X平台的HTTP库，不过当下载线程数超过2个时，就会影响到主线程响应用户请求的速度了。经测试发现completionBlock总是在主线程调用，而NSOperation的文档中却说一般会在子线程中执行。
于是看了下ASIHTTPRequest.m，终于发现问题所在了：

// Subclasses might override this method to process the result in the same thread// If you do this, don't forget to call [super requestFinished] to let the queue / delegate know we're done- (void)requestFinished{#if DEBUG_REQUEST_STATUS || DEBUG_THROTTLING    NSLog(@"[STATUS] Request finished: %@",self);#endif    if ([self error] || [self mainRequest]) {        return;    }    if ([self isPACFileRequest]) {        [self reportFinished];    } else {        [self performSelectorOnMainThread:@selector(reportFinished) withObject:nil waitUntilDone:[NSThread isMainThread]];    }}

这段代码显示了，在不使用自动代理脚本时，就会在主线程执行reportFinished。

解决的办法很简单，可以按它所说的继承ASIHTTPRequest，并改写requestFinished方法。或者像我这种懒人，直接改源码：

- (void)requestFinished{#if DEBUG_REQUEST_STATUS || DEBUG_THROTTLING    NSLog(@"[STATUS] Request finished: %@",self);#endif    if ([self error] || [self mainRequest]) {        return;    }    [self reportFinished];}

改完后重新构建一遍，发现至少5个下载线程时也不会影响主线程了，搞定收工~