Alamofire http json请求块ui

响应关闭在主线程上执行。如果您在那里进行JSON解析（并且您有大量数据），它将阻塞主线程一段时间。

在这种情况下，您应该将其dispatch_async用于JSON解析，并且仅在完成后更新主线程。

像这样做你的解析

func getRecent() {

var url = "http://URL/recent.php?lastid=\(lastObjectIndex)&limit=\(numberOfRecordsPerAPICall)"


isApiCalling = true
request(.GET, url, parameters: nil)
    .response { (request, response, data, error) in
        if error == nil {

    let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
    dispatch_async(dispatch_get_global_queue(priority, 0)) {

        // Parse stuff here

        let data: AnyObject = data!
        let jsonArray = JSON(data: data as! NSData)
        if jsonArray.count < self.numberOfRecordsPerAPICall {
            self.recentCount = 0
            self.tableVIew.tableFooterView = nil
        } else {
            self.recentCount = jsonArray.count
            self.tableVIew.tableFooterView = self.footerView
        }
        for (key: String, subJson: JSON) in jsonArray {
            // Create an object and parse your JSON one by one to append it to your array
            var httpUrl = subJson["image_url"].stringValue
            let url = NSURL(string: httpUrl)
            let data = NSData(contentsOfURL: url!)

            if UIImage(data: data!) != nil {

            // Create an object and parse your JSON one by one to append it to your array
            var newNewsObject = News(id: subJson["id"].intValue, title: subJson["title"].stringValue, link: subJson["url"].stringValue, imageLink: UIImage(data: data!)!, summary: subJson["news_text"].stringValue, date: self.getDate(subJson["date"].stringValue))

            self.recentArray.append(newNewsObject)
            }
        }

        dispatch_async(dispatch_get_main_queue()) {

            // Update your UI here

            self.lastObjectIndex = self.lastObjectIndex + self.numberOfRecordsPerAPICall
            self.isApiCalling = false
            self.tableVIew.reloadData()
            self.refreshControl?.endRefreshing()
        }
    }
    }
    }
}