UIVideoEditorController类包含了由系统提供的界面，使用户可以交互式的剪切视频

• (IBAction)click:(UIButton *)sender {
  UIImagePickerController *myImagePickerController = [[UIImagePickerController alloc] init];
  myImagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
  myImagePickerController.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:myImagePickerController.sourceType];
  myImagePickerController.delegate = self;
  myImagePickerController.editing = NO;
  [self presentViewController:myImagePickerController animated:YES completion:nil];
  }

pragma mark - UIImagePickerControllerDelegate

• (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
  [picker dismissViewControllerAnimated:YES completion:^{
  NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
  if([mediaType isEqualToString:@"public.movie"]) {
  NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];

                UIVideoEditorController *editVC;              
          // 检查这个视频资源能不能被修改 
               if ([UIVideoEditorController canEditVideoAtPath:videoURL.path]) {  
                      editVC = [[UIVideoEditorController alloc] init]; 
                      editVC.videoPath = videoURL.path; editVC.delegate = self; 
               } 
               [self presentViewController:editVC animated:YES completion:nil];
         } 
     }];
  

}

//编辑成功后的Video被保存在沙盒的临时目录中

• (void)videoEditorController:(UIVideoEditorController *)editor didSaveEditedVideoToPath:(NSString *)editedVideoPath {
  NSLog(@"+++++++++++++++%@",editedVideoPath);
  }

// 编辑失败后调用的方法

• (void)videoEditorController:(UIVideoEditorController *)editor didFailWithError:(NSError *)error {
  NSLog(@"%@",error.description);
  }

//编辑取消后调用的方法

• (void)videoEditorControllerDidCancel:(UIVideoEditorController *)editor {

}