通过手机其他iOS应用打开此文件

 根据所处理文档的格式，提供本地设备（InApp）能处理该格式文档的所有应用（App）。比如，demo中所处理的是pdf格式的文档，那么可以打开该文档的本地app有邮件、打印等等。仅支持ARC。

demo： 

https://github.com/honkmaster/TTOpenInAppActivity

Requirements

• As UIActivity is iOS 6 only, so is the subclass.
• This project uses ARC. If you want to use it in a non ARC project, you must add the -fobjc-arc compiler flag to TTOpenInAppActivity.m in Target Settings > Build Phases > Compile Sources.

Installation

Add the TTOpenInAppActivity subfolder to your project. Required libraries: UIKit, CoreGraphics, ImageIO and MobileCoreServices.

Usage.

• We keep a weak referemce to the superview (UIActionSheet). In this way we dismiss the UIActionSheet ans instead display the UIDocumentInterActionController.
• TTOpenInAppActivity needs to be initalized with the current view (iPhone & iPad) and a) a CGRect or b) a UIBarButtonItem (both only for iPad) from where it can present the UIDocumentInterActionController.
• See example project.

NSURL *URL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"empty" ofType:@"pdf"]];
TTOpenInAppActivity *openInAppActivity = [[TTOpenInAppActivity alloc] initWithView:self.view andRect:((UIButton *)sender).frame];
UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:@[URL] applicationActivities:@[openInAppActivity]];

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone){
    // Store reference to superview (UIActionSheet) to allow dismissal
    openInAppActivity.superViewController = activityViewController;
    // Show UIActivityViewController 
    [self presentViewController:activityViewController animated:YES completion:NULL];
} else {
    // Create pop up
    self.activityPopoverController = [[UIPopoverController alloc] initWithContentViewController:activityViewController];
    // Store reference to superview (UIPopoverController) to allow dismissal
    openInAppActivity.superViewController = self.activityPopoverController;
    // Show UIActivityViewController in popup
    [self.activityPopoverController presentPopoverFromRect:((UIButton *)sender).frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
}