ios 预览文件-QLPreviewController用法

在应用中，我们有时想预览文件，但是又不想为此而专门写一个viewController。这时QLPreviewController的作用就来了。

QLPreviewController最简单的用法如下：

　NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];

　NSString *fileName = [path stringByAppendingPathComponent:@"test.jpg"];

NSURL *fileRUL = [NSURL fileURLWithPath:fileName];

self.documentInteractionController = [UIDocumentInteractionController interactionControllerWithURL:fileRUL];

self.documentInteractionController.delegate = self;
        
[self.documentInteractionController presentPreviewAnimated:YES];

结果如下：

具体如何设定预览的内容和行为，是在QLPreviewControllerDelegate和QLPreviewControllerDataSource中完成的，所以这里只需要在controller中实现QLPreviewControllerDelegate和QLPreviewControllerDataSource相关方法即可

// Returns the number of items that the preview controller should preview
- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)previewController
{
    NSInteger numToPreview = 0;
    
    NSIndexPath *selectedIndexPath = [self.tableView indexPathForSelectedRow];
    if (selectedIndexPath.section == 0)
        numToPreview = NUM_DOCS;
    else
        numToPreview = self.documentURLs.count;
    
    return numToPreview;
}


// returns the item that the preview controller should preview
- (id)previewController:(QLPreviewController *)previewController previewItemAtIndex:(NSInteger)idx
{
    NSURL *fileURL = nil;
    
    NSIndexPath *selectedIndexPath = [self.tableView indexPathForSelectedRow];
    if (selectedIndexPath.section == 0)
    {
        fileURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:documents[idx] ofType:nil]];
    }
    else
    {
        fileURL = [self.documentURLs objectAtIndex:idx];
    }
    
    return fileURL;
}

另外一些解决方案：

在SDK中打开其他接入应用的解决方案

http://blog.csdn.net/arthurchenjs/article/details/6920631

应用程序间通讯 - URL Scheme

http://blog.csdn.net/flower4wine/article/details/6454957

 在Mac和iOS中注册自定义的URL Scheme

 http://cocoa.venj.me/blog/custom-url-scheme-on-mac-and-ios/

iOS应用中打开一些其他应用的URL-Scheme

http://willonboy.tk/?p=742

iPhone开发技巧 URL Scheme启动进程调试教程

http://mobile.51cto.com/iphone-278973.htm

应用之间调用

http://blog.csdn.net/pjk1129/article/details/6641211