Question

我正在使用此代码使用照片框架从相册中检索照片，我已成功检索到PHAssets并将其放入数组，但我无法将其转换为图像，在此过程中崩溃。

这是我的代码，

-(void)retrieveAllPhotoSetWithCompletionCallback:(void(^ __nonnull)(NSMutableArray * __nullable asset ,NSMutableArray * __nullable imageArray , BOOL complete))completionCallback{

    self.requestOptions = [[PHImageRequestOptions alloc] init];
    self.requestOptions.resizeMode   = PHImageRequestOptionsResizeModeExact;
    self.requestOptions.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
    self.requestOptions.synchronous = YES;

    NSMutableArray *assetsArray = [NSMutableArray new];
    PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:nil];
    [fetchResult enumerateObjectsUsingBlock:^(PHAsset *_Nonnull asset, NSUInteger idx, BOOL * _Nonnull stop) {

        [assetsArray addObject:asset];
    }];

    PHImageManager *manager = [PHImageManager defaultManager];
    NSMutableArray *images = [NSMutableArray arrayWithCapacity:[assetsArray count]];

    // assets contains PHAsset objects.
//    __block UIImage *ima;
    int i = 0;

    for(PHAsset *asset in assetsArray) {
        // This autorelease pool seems good (a1)
        @autoreleasepool {

            [manager requestImageForAsset:asset
                               targetSize:PHImageManagerMaximumSize
                              contentMode:PHImageContentModeDefault
                                  options:self.requestOptions
                            resultHandler:^(UIImage *image, NSDictionary *info) {

                                dispatch_async(dispatch_get_main_queue(), ^{

                        //you can add autorelease pool here as well (a2)
                    @autoreleasepool {

                        //assetCount++;
                        NSLog(@"started requesting image %i", i);

                        NSError *error = [info objectForKey:PHImageErrorKey];

                        if (error)
                            NSLog(@"Image request error: %@",error);
                        else {
                            NSString *imagePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0] stringByAppendingPathComponent:[NSString stringWithFormat:@"%i.png",i]];
                            NSData *imageData = UIImagePNGRepresentation(image);
                            if(imageData) {
                                [imageData writeToFile:imagePath atomically:YES];
                                [images addObject:imagePath];
                            }
                            else {
                                NSLog(@"Couldn't write image data to file.");
                            }
                            NSLog(@"finished requesting image %i", i);
                        }
                    } //a2 ends here
                });
            }];
            i++;
        } // a1 ends here
    }
    completionCallback(assetsArray,images,YES);
}

Answer 1

我认为问题在于requestImageForAsset:asset targetSize:PHImageManagerMaximumSize这里你正在采用程序中可用的最大尺寸。这导致将最大尺寸的图像存储在RAM中。通过存储多个它会占用更多的RAM内存，它会崩溃。我调整了targetSize的大小，内存使用量比以前少了。

从PHAssets请求图像数组导致内存异常

1 个答案: