Question

使用以下代码时，它会获取我的最后一张照片，但它会复制它。它总是得到最后一张图片，但它会成对返回：

UIImageView *imageView = (UIImageView *) [self.photoCollectionView viewWithTag:101];
PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
fetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:fetchOptions];
PHAsset *lastAsset = [fetchResult lastObject];
[[PHImageManager defaultManager] requestImageForAsset:lastAsset
                                targetSize:imageView.bounds.size
                                contentMode:PHImageContentModeAspectFill
                                options:nil
                                resultHandler:^(UIImage *result, NSDictionary *info) {
                                NSLog(@"PHImageManager request results %@ and info %@", result, info);
                                dispatch_async(dispatch_get_main_queue(), ^{
                                    [user_photos addObject:result];
                                    NSLog(@"%lu",user_photos.count);
                                    [self.photoCollectionView reloadData];
                                    NSLog(@"%lu",user_photos.count);
                                });
}];

出现这种情况的原因是什么？以下是日志声明：

2015-09-06 21:48:22.153[41357:11390462] PHImageManager request results <UIImage: 0x7fd1336b8f40>, {60, 40} and info {
PHImageFileOrientationKey = 0;
PHImageResultDeliveredImageFormatKey = 4031;
PHImageResultIsDegradedKey = 1;
PHImageResultRequestIDKey = 1;
PHImageResultWantedImageFormatKey = 5003;
}
2015-09-06 21:48:22.158[41357:11390462] 2
2015-09-06 21:48:22.159[41357:11390462] 2

2015-09-06 21:48:22.166[41357:11390462] PHImageManager request results <UIImage: 0x7fd13374c3b0>, {386, 256} and info {
PHImageFileOrientationKey = 0;
PHImageResultDeliveredImageFormatKey = 5003;
PHImageResultIsDegradedKey = 0;
PHImageResultRequestIDKey = 1;
PHImageResultWantedImageFormatKey = 5003;
}
2015-09-06 21:48:22.167[41357:11390462] 3
2015-09-06 21:48:22.167[41357:11390462] 3

这发生在模拟器＆amp;在设备上。我认为，不使用第三方软件，这不重要。它为什么被叫两次？我在一个uialertaction块中称它为

Answer 1

做了一些关于＆＃34; PHImageResultIsDegradedKey＆＃34;是的，当然，它归结为操作系统检索图像数据，并在它得到它之后根据设置调整质量输出的大小，这就是为什么我看到第二个图像。

所以我所做的是在资产的实际请求之前添加了PHImageRequestOptions参数，它只检索了我想要的照片：

...
PHAsset *lastAsset = [fetchResult lastObject];
PHImageRequestOptions * options = [[PHImageRequestOptions alloc] init];
options.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
options.synchronous = NO;
options.resizeMode = PHImageRequestOptionsVersionOriginal;
options.networkAccessAllowed = NO;
[[PHImageManager defaultManager] requestImageForAsset:lastAsset
                             targetSize:imageView.bounds.size
                             contentMode:PHImageContentModeAspectFit
                             options:options
                             resultHandler:^(UIImage *result, NSDictionary *info) {
                             ...

Answer 2

仅使用

替换代码中的

PHAsset *lastAsset=fetchResult;

<context-param>
  <param-name>contextConfigLocation</param-name>
    <param-value>
    /WEB-INF/spring/spring.xml
    </param-value>
</context-param>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 
</listener> 
<listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class> 
</listener>

从用户照片库中获取最后一张照片，返回两张照片

2 个答案: