UIDocumentInteractionController瀏覽文件

之前寫的一個項目打開文件直接用的UIWebView，word、excel、tex等等打開很方便。這次寫項目用到了UIDocumentInteractionController，這是IOS提供的使用其他程序打開你的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) {

        // 無法打開的文件類型

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

        UIViewController *rootVC = appDelegate.window.rootViewController;

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

    }

這種方法是可行的但是一開始用的時候我並沒有在主線程中使用，因爲是UI的變動，所以一定要在主線程中

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(), ^{

                     // 瀏覽寫在這裏

                 });

             });

報錯信息如下：

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
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26  0x183b7153c pthread_mutex_lock
27  0x183b71020 start_wqthread