didFinishPickingMediaWithInfo返回无照片

Question

我正在努力捕获使用4.0返回的图像- (void)imagePickerController:(UIImagePickerController *)picker     didFinishPickingMediaWithInfo:(NSDictionary *)info{    [[picker parentViewController] dismissModalViewControllerAnimated:YES];     // MediaType can be kUTTypeImage or kUTTypeMovie. If it's a movie then you    // can get the URL to the actual file itself. This example only looks for images.    //       NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];    // NSString* videoUrl = [info objectForKey:UIImagePickerControllerMediaURL];    // Try getting the edited image first. If it doesn't exist then you get the    // original image.    //    if (CFStringCompare((CFStringRef) mediaType,  kUTTypeImage, 0) == kCFCompareEqualTo) {                       UIImage* picture = [info objectForKey:UIImagePickerControllerEditedImage];        if (!picture)            picture = [info objectForKey:UIImagePickerControllerOriginalImage];                     // **picture is always nil            // info dictionary count = 1    }}发生的情况是，信息字典总是返回一个条目：{UIImagePickerControllerMediaType =“ public.image”;很棒，但是从来没有图像。我在这个论坛上使用了一个很好的例子来做到这一点，我很确定调用是正确的，但是从来没有图像。

Answer 1

尽管Matthew Frederick的回答最受欢迎，并且长期以来一直是适当的回应，从iOS 5.0（苹果可用）开始dismissViewControllerAnimated:completion:，以取代现已弃用的（从iOS 6.0开始）dismissViewControllerAnimated:。

希望在完成块中执行图像信息字典检索应该对所有人都有意义。

从上面举个例子，现在看起来像：

- (void)    imagePickerController:(UIImagePickerController *)picker 

    didFinishPickingMediaWithInfo:(NSDictionary *)info 

{

    [picker dismissViewControllerAnimated:YES completion:^{

          // Edited image works great (if you allowed editing)

        myUIImageView.image = [info objectForKey:UIImagePickerControllerEditedImage];

          // AND the original image works great

        myUIImageView.image = [info objectForKey:UIImagePickerControllerOriginalImage];

          // AND do whatever you want with it, (NSDictionary *)info is fine now

        UIImage *myImage = [info objectForKey:UIImagePickerControllerEditedImage];

    }];

}

Answer 2

我已经尝试了所有上述操作，但是在iPad 6.0 / 6.1模拟器上却没有运气，但是我发现信息包含“ UIImagePickerControllerReferenceURL”键，这是我的代码：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

  [picker dismissViewControllerAnimated:YES completion:NULL];

  UIImage* image = [info objectForKey:UIImagePickerControllerOriginalImage];

  if(NULL == image){

      [MyImageLoader loadImageFromAssertByUrl:[info objectForKey:@"UIImagePickerControllerReferenceURL"]

                                   completion:^(UIImage* img){

                                        //img not null here

                                   }];

  }else{

      //image not null here

  }

}

而loadImageFromAssertByUrl的代码是：

+(void) loadImageFromAssertByUrl:(NSURL *)url completion:(void (^)(UIImage*)) completion{

  ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];

  [assetLibrary assetForURL:url resultBlock:^(ALAsset *asset) {

      ALAssetRepresentation *rep = [asset defaultRepresentation];

      Byte *buffer = (Byte*)malloc(rep.size);

      NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:rep.size error:nil];

      NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];

      UIImage* img = [UIImage imageWithData:data];

      completion(img);

  } failureBlock:^(NSError *err) {

      NSLog(@"Error: %@",[err localizedDescription]);

  }];

}