Question

我想在单击视频按钮时从photoGallery获取视频，并在同一视图中显示。我已经编写了这段代码，但是没有将视频放到同一视图的imageview中。

- (IBAction)vedioClicked:(id)sender
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
imagePicker.allowsEditing = YES;

imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePicker.mediaTypes =
[[NSArray alloc] initWithObjects: (NSString *) kUTTypeMovie, nil];
[self presentViewController:imagePicker animated:YES completion:nil];

}

- (void) imagePickerController: (UIImagePickerController *) picker  didFinishPickingMediaWithInfo: (NSDictionary *) info
{
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];

if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) 

{
UIImage *editedImage = (UIImage *)[info objectForKey:@"UIImagePickerControllerOriginalImage"];

// Compressing the image size

CGSize newSize = CGSizeMake(400, 400);
UIGraphicsBeginImageContext(newSize);
[editedImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

// Get the new image from the context
inputImage = UIGraphicsGetImageFromCurrentImageContext();
self.imageView.image=inputImage;

// End the context

UIGraphicsEndImageContext();

NSData *data =  UIImageJPEGRepresentation(inputImage,0.2);//PNGRepresentation(imgView.image);

}
else if ([mediaType isEqualToString:@"public.movie"]){

NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];

}
self.imageView.image=inputImage;   
[picker dismissViewControllerAnimated:YES completion:nil];

}

视频来自照片库，但它不会在同一视图中显示到imageView，所以任何人都可以帮我做到这一点。任何帮助都会更受欢迎。

Answer 1

我们无法在UIImageView中直接显示视频。如果我们尝试直接加载，它将仅显示黑屏。要在UIImageView中显示视频，我们需要加载第一帧视频。为此需要导入两个框架。

1.AVFoundation

2.AssetsLibrary

使用这两个我们可以将第一帧视频显示到UIImageView中，如下所示：

- (void) imagePickerController: (UIImagePickerController *) picker  didFinishPickingMediaWithInfo: (NSDictionary *) info
{
   NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];

  if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) 
  {
     UIImage *editedImage = (UIImage *)[info objectForKey:@"UIImagePickerControllerOriginalImage"];

  // Compressing the image size

    CGSize newSize = CGSizeMake(400, 400);
    UIGraphicsBeginImageContext(newSize);
    [editedImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

   // Get the new image from the context
   inputImage = UIGraphicsGetImageFromCurrentImageContext();
   self.imageView.image=inputImage;

   // End the context

    UIGraphicsEndImageContext();

   NSData *data =  UIImageJPEGRepresentation(inputImage,0.2);//PNGRepresentation(imgView.image);

  }
  else if ([mediaType isEqualToString:@"public.movie"])
  {

    NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];

    AVAsset *avAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];

    if ([[avAsset tracksWithMediaType:AVMediaTypeVideo] count] > 0)
    {
      AVAssetImageGenerator *imageGenerator =[AVAssetImageGenerator assetImageGeneratorWithAsset:avAsset];
      Float64 durationSeconds = CMTimeGetSeconds([avAsset duration]);
      CMTime midpoint = CMTimeMakeWithSeconds(durationSeconds/2.0, 600);
      NSError *error;
      CMTime actualTime;

      CGImageRef halfWayImage = [imageGenerator copyCGImageAtTime:kCMTimeZero actualTime:&actualTime error:&error];

      if (halfWayImage != NULL)
      {

         NSString *actualTimeString = (NSString *)CFBridgingRelease(CMTimeCopyDescription(NULL, actualTime));
         NSString *requestedTimeString = (NSString *)CFBridgingRelease(CMTimeCopyDescription(NULL, midpoint));
         NSLog(@"Got halfWayImage: Asked for %@, got %@", requestedTimeString, actualTimeString);

          UIImage *img=[UIImage imageWithCGImage:halfWayImage];
          self.imageView.image=img;

       }

     }
  }

   [picker dismissViewControllerAnimated:YES completion:nil];

}

如何在iOS中使用UIImagePickerController从photoGallery获取视频？

1 个答案: