UIDocumentInteractionController浏览文件

之前写的一个项目打开文件直接用的UIWebView，word、excel、tex等等打开很方便。这次写项目用到了UIDocumentInteractionController，这是IOS提供的使用其他程序打开你的App不支持的文件格式。

    UIDocumentInteractionController *documentInteractionController = [UIDocumentInteractionController
interactionControllerWithURL:[NSURL
fileURLWithPath:url]];

    [documentInteractionController setDelegate:[FileOpenTool
sharedInstance]];

    BOOL canShow = [documentInteractionController
presentPreviewAnimated:YES];

    

    if (!canShow) {

        // 无法打开的文件类型

        AppDelegate *appDelegate = (AppDelegate *)[[UIApplication
sharedApplication]
delegate];

        UIViewController *rootVC = appDelegate.window.rootViewController;

        [v presentOptionsMenuFromRect:CGRectZero
inView:rootVC.view
animated:YES];

    }
这种方法是可行的但是一开始用的时候我并没有在主线程中使用，因为是UI的变动，所以一定要在主线程中

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,
0), ^{

                 // Do time-consuming task in background thread

                 // Return back to main thread to update UI

                 dispatch_sync(dispatch_get_main_queue(), ^{

                     // 浏览写在这里

                 });

             });

报错信息如下：
bool _WebTryThreadLock(bool), 0x1556d49d0: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...

1   0x187dd0f8c WebThreadLock

2   0x18929ea68 <redacted>

3   0x18927508c <redacted>

4   0x189274f64 <redacted>

5   0x189408f04 <redacted>

6   0x189049810 <redacted>

7   0x18905803c <redacted>

8   0x1892eb6c0 <redacted>

9   0x18905f4b4 <redacted>

10  0x18924a88c <redacted>

11  0x18936a244 <redacted>

12  0x18924a404 <redacted>

13  0x1892046cc <redacted>

14  0x18910fd28 <redacted>

15  0x18910fa04 <redacted>

16  0x18910f96c <redacted>

17  0x18904c0e4 <redacted>

18  0x1869f2a28 <redacted>

19  0x1869ed634 <redacted>

20  0x1869ed4f4 <redacted>

21  0x1869ecb24 <redacted>

22  0x1869ec86c <redacted>

23  0x186a1bc90 <redacted>

24  0x183b721e0 <redacted>

25  0x183b71d58 <redacted>

26  0x183b7153c pthread_mutex_lock

27  0x183b71020 start_wqthread