pragma mark -- 发送文件

-(void)onSendFileBtnPressed:(id)sender{
    if ([[[UIDevice currentDevice] systemVersion] floatValue] < 8.0) {
        //older than iOS 8 code here
        NSLog(@"IOS8以上才支持icloud drive.");
    } else {
        //iOS 8 specific code here
        NSArray *documentTypes = @[@"public.content", @"public.text", @"public.source-code ", @"public.image", @"public.audiovisual-content", @"com.adobe.pdf", @"com.apple.keynote.key", @"com.microsoft.word.doc", @"com.microsoft.excel.xls", @"com.microsoft.powerpoint.ppt"];
        
        UIDocumentPickerViewController *documentPicker = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:documentTypes inMode:UIDocumentPickerModeOpen];
        documentPicker.delegate = self;//代理 UIDocumentPickerDelegate
        documentPicker.modalPresentationStyle = UIModalPresentationFormSheet;
        [self presentViewController:documentPicker animated:YES completion:nil];
    }
}

#pragma mark-- UIDocumentPickerDelegate
- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentAtURL:(NSURL *)url {
    BOOL fileUrlAuthozied = [url startAccessingSecurityScopedResource];
    if(fileUrlAuthozied){
        NSFileCoordinator *fileCoordinator = [[NSFileCoordinator alloc] init];
        NSError *error;
        
        [fileCoordinator coordinateReadingItemAtURL:url options:0 error:&error byAccessor:^(NSURL *newURL) {
            //文件路径
            NSString *urlStr =url.absoluteString;

           //你的从操作
        }];
    }else{
        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"" message:NSLocalizedString(@"申请访问受限", nil) delegate:nil cancelButtonTitle:NSLocalizedString(@"I know", nil) otherButtonTitles: nil];
        [alert show];
        [alert release];;
        
    }
}