NSMutableArray 在将 UIImage 添加到数组后返回 nil

Question

我想获取 photoLibrary 中拍摄的最后一张照片，并将其添加到将在 UIActivivtyViewController 中使用的数组中。当显示 UIActivityViewController 时，图像未显示，并且 UIImage 似乎从未添加到数组中。

这是我的，

NSMutableArray *items = [[NSMutableArray alloc]init];
[items addObject:@"someText"];

PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
fetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:fetchOptions];
PHAsset *lastAsset = [fetchResult lastObject];


__block UIImage *shareImage;

PHImageRequestOptions* options = [[PHImageRequestOptions alloc]init];
options.resizeMode = PHImageRequestOptionsResizeModeExact;
options.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
options.version = PHImageRequestOptionsVersionUnadjusted;
options.synchronous = YES;


[[PHImageManager defaultManager] requestImageForAsset:lastAsset


    targetSize:PHImageManagerMaximumSize
    contentMode:PHImageContentModeDefault
    options:PHImageRequestOptionsVersionCurrent
    resultHandler:^(UIImage *result, NSDictionary *info) {

    dispatch_async(dispatch_get_main_queue(), ^{



    shareImage = result;
    [items addObject:shareImage];  });



}];

NSMutableArray *activityItems = [NSMutableArray arrayWithArray:items];
UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];
[self presentViewController:activityViewController animated:YES completion:nil];

如有任何帮助，我们将不胜感激。我是 iOS 开发和编程的新手，我在这方面遇到了很多困难。

谢谢

Answer 1

UIImage 实际上已添加到您的 items 数组中。在您创建 activityItems 数组并显示 UIActivityViewController 时，添加 UIImage 的块可能尚未完成。如果您将呈现逻辑添加到块中（在将图像添加到数组之后），它应该可以工作！

- (void)yourMethod {
    NSMutableArray *items = [[NSMutableArray alloc] init];
    [items addObject:@"someText"];

    PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
    fetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
    PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:fetchOptions];
    PHAsset *lastAsset = [fetchResult lastObject];

    PHImageRequestOptions *options = [[PHImageRequestOptions alloc]init];
    options.resizeMode = PHImageRequestOptionsResizeModeExact;
    options.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
    options.version = PHImageRequestOptionsVersionUnadjusted;
    options.synchronous = YES;

    [[PHImageManager defaultManager] requestImageForAsset:lastAsset
                                               targetSize:PHImageManagerMaximumSize
                                              contentMode:PHImageContentModeDefault
                                                  options:PHImageRequestOptionsVersionCurrent
                                            resultHandler:^(UIImage *result, NSDictionary *info) {
                                                dispatch_async(dispatch_get_main_queue(), ^{
                                                    [items addObject:result];

                                                    [self presentActivityControllerWithItems:items];
                                                });
                                            }];
}

- (void)presentActivityControllerWithItems:(NSArray *)items {
    UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];
    [self presentViewController:activityViewController animated:YES completion:nil];
}

NSMutableArray 在将 UIImage 添加到数组后返回 nil

NSMutableArray returning nil after adding a UIImage to the array

xcode

objective-c

uiimage

ios

phphotolibrary