如何从ALAssetsLibrary iOS获取图像实际大小

Question

我正在尝试从ALAssetsLibrary中选择所有实际尺寸的图像并将其保存在文档文件夹中。 这是我的代码从ALAssetsLibrary获取真实尺寸图像。出现以下错误。是否还有其他方法从ALAssetsLibrary获取真实尺寸图像？

与资产的连接中断或资产死亡

-(void)test{

    for (int i= 0; i < chosenImagesArray.count; i++) {
            NSDictionary *chosenImage = [self.chosenImages objectAtIndex:i];
                ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];
                [assetLibrary assetForURL:[chosenImage valueForKey:UIImagePickerControllerReferenceURL] resultBlock:^(ALAsset *asset)
                 {
                     ALAssetRepresentation *rep = [asset defaultRepresentation];

                     unsigned long imageDataSize = (unsigned long)[rep size];
                     imageDataBytes = malloc(imageDataSize);
                     [rep getBytes:imageDataBytes fromOffset:0 length:imageDataSize error:nil];
                     NSData *data = [NSData dataWithBytesNoCopy:imageDataBytes length:imageDataSize freeWhenDone:YES];
                     UIImage *myImg =[UIImage imageWithData:data];

                     //Crop to Standard Size
                     UIImage *readyToWriteImage = [self croppIngimageByImageName:[self fixrotation:myImg ] ];
                     //Write To Document Directory
                     [self writeChosenImage:readyToWriteImage];




                 }
                 failureBlock:^(NSError *err) {
                                  NSLog(@"Error: %@",[err localizedDescription]);

                                 return ;
                  }];

            }

}

Answer 1

您可以按照本教程“如何获取图像的元数据”进行操作，因为大小位于图像的元数据中，因此您可以从返回的元数据字典中获取大小，这是链接http://blog.codecropper.com/2011/ 05 /获取元数据-从图像上-IOS /

谢谢