AFNetworking 阻止 UI

Question

我正在使用 AFNetworking 从服务器请求数据，如果网络连接不好，接收数据需要很长时间，所以如果我不想等待并决定返回，它将不允许我（阻止 UI），如果我不想等待数据加载，我应该怎么做才能返回。

下面是我用于 API 调用的代码：

class func  performHTTPGetOnUrl(url: NSString , withParams dictionary: NSMutableDictionary? , withDelegate delegate:ConnectionManagerDelegate)
{
    print("url is \(url) & params are \(dictionary)")
    let manager = AFHTTPRequestOperationManager()
    manager.requestSerializer = AFJSONRequestSerializer(writingOptions: []) //1
    manager.responseSerializer = AFJSONResponseSerializer() //2
    manager.responseSerializer.acceptableContentTypes = NSSet(objects: "application/json") as Set<NSObject>
    manager.responseSerializer.acceptableContentTypes = NSSet(array: ["text/plain", "text/html", "application/json"]) as Set<NSObject>

    //3

    manager.GET(url as String,
        parameters: dictionary,
        success: {(operation: AFHTTPRequestOperation!, responseObject: AnyObject!) in

            print("inside connectionManager success")

            delegate.requestSucceededWithJsonResponse(responseObject!)
        },
        failure: { (operation: AFHTTPRequestOperation!, error: NSError!) in
            print("inside failure block of get ")
            delegate.requestFailedWithError(error!)
    })


}

Answer 1

不确定是什么阻止了 UI 查看此代码，因为这些方法（应该）已经异步了...您是否有一些调用此代码的东西会阻塞，直到此 web 服务调用完成？否则尝试将整个事情包装在一个调度队列中，如

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), {
 // do stuff
});

如果有 ui 更新

，你的委托回调应该返回到主线程

dispatch_sync(dispatch_get_main_queue(), {
    delegate.requestSucceededWithJsonResponse(responseObject!)
});

Answer 2

所有 UI 更新 必须在主线程中完成。您可以检查您的当前流程是否在主线程上，并决定在必要时调用 dispatch_get_main_queue：

if NSThread.isMainThread() {
   print("this flow is in the main thread..")
} else {
   print("warning, this is not the main thread..")
   // apply your dispatch_get_main_queue..
}

Answer 3

您可以为您的请求添加时间间隔。如果在该时间间隔内未收到响应，则请求将被取消。使用以下代码添加请求的时间间隔。

[manager.requestSerializer setTimeoutInterval:30];

AFNetworking 阻止 UI

AFNetworking Block the UI

ios

afnetworking

swift