是否可以使用图像名称从 iPad 照片库中获取图像

Question

在这里，我将一个名为 image1.png 的图像手动加载到 iPad 照片库中，并且需要在我的 iPad 应用程序中获取相同的图像。图像我被替换为具有相同名称的新图像，我的目的是在需要时更改图像而不进行任何代码更改。我没有选择将图像保存在服务器中并从那里访问，所以我正在寻找这样的解决方案。请帮帮我

Answer 1

您可能希望将其保存到本地存储：

// Assuming 'newImage' is a 'UIImage' object containing your image
NSData *imageData = UIImagePNGRepresentation(newImage);

NSArray *paths =      NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *imagePath =[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.png",@"yourImageName"]];

NSLog((@"pre writing to file"));
if (![imageData writeToFile:imagePath atomically:NO]) 
{
    NSLog((@"Failed to cache image data to disk"));
}
else
{
    NSLog((@"the cachedImagedPath is %@",imagePath)); 
    // Persist path in a dictionary or NSUserDefaults
}

稍后像这样检索它：

NSString *theImagePath = [yourDictionary objectForKey:@"cachedImagePath"];
UIImage *customImage = [UIImage imageWithContentsOfFile:theImagePath];

来自here的代码。

Answer 2

我没有使用图像名称从 iPad 库加载图像的解决方案，因此我将所有图像保存在一个用户库中并从我的 iPad 应用程序加载这些图像。

-(void)loadImageFromLibrary
{
   __block UIImage *ima;

    NSMutableArray *images=[NSMutableArray new];

    PHAsset *asset = nil;

    PHAssetCollection *collection;

    NSArray *collectionsFetchResults;

    NSMutableArray *localizedTitles = [[NSMutableArray alloc] init];

    PHFetchResult *userCollections = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];

    collectionsFetchResults = @[userCollections];//to get images from user created library.

    for (int i = 0; i < collectionsFetchResults.count; i ++) {

        PHFetchResult *fetchResult = collectionsFetchResults[i];

        for (int x = 0; x < fetchResult.count; x ++) {

            collection = fetchResult[x];
            localizedTitles[x] = collection.localizedTitle;//get library names
        }

    }//MyImages is my image library
    if ([collection.localizedTitle isEqualToString:@"MyImages"]) {

        PHFetchResult *fetchResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];

        if (fetchResult != nil && fetchResult.count > 0) {

            for (asset in fetchResult) {

                PHImageRequestOptions * imageRequestOptions = [[PHImageRequestOptions alloc] init];

                imageRequestOptions.synchronous = YES;

                [[PHImageManager defaultManager] requestImageForAsset:asset

                                                           targetSize:PHImageManagerMaximumSize

                                                          contentMode:PHImageContentModeDefault

                                                              options:imageRequestOptions

                                                        resultHandler:^void(UIImage *image, NSDictionary *info) {

                                                            NSLog(@"info = %@", info);

                                                            ima = image;

                                                        }];

                [images addObject:ima];

            }

        }
    }
}

使用这个功能我解决了我的问题。它可能很有用。