从图库加载照片

Question

我有一张来自相机胶卷的NSURL照片，我想加载图片或NSData。

我试试这个：

NSData *imageDataTemp = [NSData dataWithContentsOfURL:path];

但它返回图像大小的一半。

Answer 1

以下是如何加载具有ALAsset网址的图片。

使用ALAssetLibrary（在iOS 9.0中已弃用）

ALAssetsLibraryAssetForURLResultBlock resultBlock = ^(ALAsset *asset)
{
    ALAssetRepresentation *representation = [asset defaultRepresentation];
    CGImageRef image = [representation fullResolutionImage];

    if (image) 
    {
        yourImageView.image = [UIImage imageWithCGImage:image];
    }
};

ALAssetsLibraryAccessFailureBlock failureBlock  = ^(NSError *error)
{
    NSLog(@"Error %@", [error localizedDescription]);
};

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

[library assetForURL:assetURL 
         resultBlock:resultBlock
        failureBlock:failureBlock];

使用PHPhotoLibrary

    NSURL *yourALAssetURL;
    PHFetchResult *result = [PHAsset fetchAssetsWithALAssetURLs:@[yourALAssetURL] options:nil];
    PHAsset *asset = result.firstObject;

    if (asset)
    {
        PHCachingImageManager *imageManager = [[PHCachingImageManager alloc] init];

        // Request an image for the asset from the PHCachingImageManager.
        [imageManager requestImageForAsset:asset
                                targetSize:CGSizeMake(100.0f, 100.0f)
                               contentMode:PHImageContentModeAspectFill
                                   options:nil
                             resultHandler:^(UIImage *image,
                                             NSDictionary *info)
         {
             NSLog(@"IMAGE: %@", image);
         }];
    }

Apple创建了一个使用PHPhotoLibrary的示例应用程序。它可用here。