title: Downloading files in serial order using NSURLConnection in iOS
body: <p>I want to download 3 files in serial order. Two of them are txt files and one is .gz file. I am using NSURLConnection to download the above files. </p>
  
  <p>I am very new to iOS Programming. I have seen in other question in SO and google that we can use serial dispatch queue to do some operation serially.</p>
  
  <p>But I don't know how to do this with NSURLConnection. I tried below but did not work.</p>
  
  <pre><code> dispatch_queue_t serialQueue = dispatch_queue_create("com.clc.PropQueue", DISPATCH_QUEUE_SERIAL);
  dispatch_async(serialQueue, ^{
      [self downloadProp];
  });
  dispatch_async(serialQueue, ^{
      [self downloadDatabase];
  });
  dispatch_async(serialQueue, ^{
      [self downloadTxt];
  });
  </code></pre>
  
  <p>Above code is not executing connectionDidFinishLoading of NSURLCOnnection. Anyone has Idea how to achieve this?</p>