title: UIActivityViewController Share Video to WeChat fails
body: <p>I want to share video in my application to wechat via "UIActivityViewController"</p>
  
  <p>But I got "transfer fail" message on WeChat's transfer dialog very often (alsmost 90%)</p>
  
  <p>But I try to save same video to my iPhone Photos, </p>
  
  <p>then share to wechat, But I never fail on it.</p>
  
  <p>Is there anything I have to do before share?</p>
  
  <p>My code:</p>
  
  <pre><code>NSMutableArray *shareFile = [[NSMutableArray alloc] init];
  
  NSURL *shared = [NSURL fileURLWithPath:file.localFilePath];
  if ([[NSFileManager defaultManager] fileExistsAtPath:file.localFilePath]) {
      [shareFile addObject: shared];
  }
  
  UIActivityViewController *_shareVC = [[UIActivityViewController alloc] initWithActivityItems:[shareFile copy] applicationActivities:nil];
  
  [_shareVC setCompletionWithItemsHandler:nil]; 
  </code></pre>