Question

我在为我正在处理的iOS应用实施相机View Controller时遇到问题。当按下一个按钮时，我有一个单独的相机对象来管理事物的AVFoundation面并捕获图像。如下所示，一旦从相机捕获UIImage，我就会通过一个使用它的完成块。

下面的第一种方法是在相机上按下捕获按钮时触发的动作。首先，通过禁用预览图层上的连接暂停摄像机图层，然后捕获图像。然后，相机对象捕获UIImage，此时我从视图中移除相机预览图层，而是添加UIImageView子视图，并将捕获的图像放在其位置。

接下来，我想使用Photos框架将图像添加到我在Photos中创建的相册中。我可以毫无问题地创建相册，并且我已经验证了PHAssetCollection对象。我在第二种方法中使用的是正确的方法。

但出于某种原因，我无法将UIImage我捕获到相册中。我尝试将我项目中的随机图像文件添加到相册中，操作成功完成。我还验证了通过使用addPhotoToSavedPhotos语句检查两种方法中的图像描述，成功将正确的图像传递给NSLog方法。这让我相信图像不知何故出了问题，但是imageView成功地显示了它，所以我不确定它可能是什么。

如果有人对我可能会尝试的解决方案有任何想法，我将不胜感激。此外，第二种方法中error.localizedDescription语句的NSLog输出"The operation couldn't be completed。（可可错误-1）。“

- (IBAction)capturePhoto:(id)sender {

    [self pauseCameraLayer];
    [[eventCamera sharedInstance] captureStillUIImage:^(UIImage *image, NSError *error){

        if(error)
        {
            NSLog(@"error capturing photo");
        }
        else
        {
            NSLog(@"%@",image.debugDescription);
        }
        [_captureButton setHidden:YES];
        [_switchCameraButton setHidden:YES];
        UIImageView *preview=[[UIImageView alloc] initWithImage:image];
        [preview setAutoresizesSubviews:YES];
        [preview setContentMode:UIViewContentModeScaleAspectFit];
        [preview setTransform:CGAffineTransformMakeRotation(M_PI_2)];
        preview.frame=_imageView.bounds;
        [_imageView addSubview:preview];
        [self addPhotoToSavedPhotos:[image copy]];
        NSLog(@"1: %@",image.description);
    }];

-(void)addPhotoToSavedPhotos:(UIImage*)photo
{
    PHAssetCollection *myCollection=[self getAPPCollection];
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        //Perform changes to photo library

        PHAssetChangeRequest *req=[PHAssetChangeRequest creationRequestForAssetFromImage:photo];
        PHAssetCollectionChangeRequest *assetChangeRequest=[PHAssetCollectionChangeRequest changeRequestForAssetCollection:myCollection];
        [assetChangeRequest addAssets:[NSArray arrayWithObject:req.placeholderForCreatedAsset]];
        //[libReq addAssets:@[assetPlaceHolder]];

    }completionHandler:^(BOOL success, NSError *error){
        //Perform any necessary actions after adding the photo to the photo 
        //library
        if(!success)
        {
            NSLog(@"didn't succeed, error: %@",error.localizedDescription);
        }
    }];
}

Answer 1

尝试这样的事情此代码将检查天气专辑是否存在

  #import <Photos/Photos.h>

    - (void)addPhotoToSavedPhotos:(UIImage *)image {
        NSString *albumName = @"NameOFTheAlbum";

        void (^saveBlock)(PHAssetCollection *assetCollection) = ^void(PHAssetCollection *assetCollection) {
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
                PHAssetCollectionChangeRequest *assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
                [assetCollectionChangeRequest addAssets:@[[assetChangeRequest placeholderForCreatedAsset]]];

            } completionHandler:^(BOOL success, NSError *error) {
                if (!success) {
                    NSLog(@"Error creating asset: %@", error);
                }
            }];
        };

        PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
        fetchOptions.predicate = [NSPredicate predicateWithFormat:@"localizedTitle = %@", albumName];
        PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:fetchOptions];
        if (fetchResult.count > 0) {
            saveBlock(fetchResult.firstObject);
        } else {
            __block PHObjectPlaceholder *albumPlaceholder;
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                PHAssetCollectionChangeRequest *changeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:albumName];
                albumPlaceholder = changeRequest.placeholderForCreatedAssetCollection;

            } completionHandler:^(BOOL success, NSError *error) {
                if (success) {
                    PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[albumPlaceholder.localIdentifier] options:nil];
                    if (fetchResult.count > 0) {
                        saveBlock(fetchResult.firstObject);
                    }
                } else {
                    NSLog(@"Error creating album: %@", error);
                }
            }];
        }
    }

Answer 2

PHAssetChangeRequest弹出权限对话框。 UI必须始终位于主线程中。

尝试将PHAssetChangeRequest移出回调。

PHAssetChangeRequest无法使用相机拍摄UIImage

2 个答案: