iOS8 Photos Framework：如何获取 PHAsset 的名称（或文件名）？

Question

我正在尝试使用 PHAssets 获取图像名称。但是我找不到文件名的元数据或任何获取图像名称的方法。有没有其他获取文件名的方法？

Answer 1

如果你想像IMG_XXX.JPG一样获取图片名称（例如照片中最后一张照片的名称），你可以试试这个：

PHAsset *asset = nil;
PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
fetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:fetchOptions];
if (fetchResult != nil && fetchResult.count > 0) {
    // get last photo from Photos
    asset = [fetchResult lastObject];
}

if (asset) {
    // get photo info from this asset
    PHImageRequestOptions * imageRequestOptions = [[PHImageRequestOptions alloc] init];
    imageRequestOptions.synchronous = YES;
    [[PHImageManager defaultManager]
             requestImageDataForAsset:asset
                            options:imageRequestOptions
                      resultHandler:^(NSData *imageData, NSString *dataUTI,
                                      UIImageOrientation orientation, 
                                      NSDictionary *info) 
     {
          NSLog(@"info = %@", info);
          if ([info objectForKey:@"PHImageFileURLKey"]) {
               // path looks like this - 
               // file:///var/mobile/Media/DCIM/###APPLE/IMG_####.JPG
               NSURL *path = [info objectForKey:@"PHImageFileURLKey"];
     }                                            
    }];
}

希望对您有所帮助。

在 Swift 中，代码将如下所示

PHImageManager.defaultManager().requestImageDataForAsset(asset, options: PHImageRequestOptions(), resultHandler:
{
    (imagedata, dataUTI, orientation, info) in
    if info!.keys.contains(NSString(string: "PHImageFileURLKey"))
    {
        let path = info![NSString(string: "PHImageFileURLKey")] as! NSURL
    }
})

Swift 4:

    let fetchResult = PHAsset.fetchAssets(with: .image, options: nil)
    if fetchResult.count > 0 {
        if let asset = fetchResult.firstObject {
            let date = asset.creationDate ?? Date()
            print("Creation date: \(date)")
            PHImageManager.default().requestImageData(for: asset, options: PHImageRequestOptions(),
                resultHandler: { (imagedata, dataUTI, orientation, info) in
                    if let info = info {
                        if info.keys.contains(NSString(string: "PHImageFileURLKey")) {
                            if let path = info[NSString(string: "PHImageFileURLKey")] as? NSURL {
                                print(path)
                            }
                        }
                    }
            })
        }
    }

Answer 2

您真正要找的是 localIdentifier，它是一个唯一的字符串，可以永久标识对象。

使用此字符串通过以下方式查找对象：

fetchAssetsWithLocalIdentifiers:options:, fetchAssetCollectionsWithLocalIdentifiers:options:, or fetchCollectionListsWithLocalIdentifiers:options: method.

有更多信息可用here

Answer 3

还有一个选项是：

[asset valueForKey:@"filename"]

这个"legality"由你决定。

Answer 4

我知道问题已经得到解答，但我想我会提供另一种选择：

extension PHAsset {
    var originalFilename: String? {
        var fileName: String?

        if #available(iOS 9.0, *) {
            let resources = PHAssetResource.assetResources(for: self)
            if let resource = resources.first {
                fileName = resource.originalFilename
            }
        }

        if fileName == nil {
            /// This is an undocumented workaround that works as of iOS 9.1
            fileName = self.value(forKey: "filename") as? String
        }

        return fileName
    }
}

Answer 5

当您引用 url 资产时，使用 Swift 的最简单答案：

if let asset = PHAsset.fetchAssetsWithALAssetURLs([referenceUrl], options: nil).firstObject as? PHAsset {

    PHImageManager.defaultManager().requestImageDataForAsset(asset, options: nil, resultHandler: { _, _, _, info in

        if let fileName = (info?["PHImageFileURLKey"] as? NSURL)?.lastPathComponent {      
            //do sth with file name
        }
    })
}

Answer 6

SWIFT4: 首先import Photos

if let asset = PHAsset.fetchAssets(withALAssetURLs: [info[UIImagePickerControllerReferenceURL] as! URL],
                                           options: nil).firstObject {


            PHImageManager.default().requestImageData(for: asset, options: nil, resultHandler: { _, _, _, info in

                if let fileName = (info?["PHImageFileURLKey"] as? NSURL)?.lastPathComponent {
                    print("///////" + fileName + "////////")
                    //do sth with file name
                }
            })
        }

Answer 7

iOS 9+ 在 Swift 4 中的最简单解决方案（基于略读答案）：

extension PHAsset {
    var originalFilename: String? {
        return PHAssetResource.assetResources(for: self).first?.originalFilename
    }
}

Answer 8

For Swift

asset?.value(forKey: "filename") as? String

For objective C

[asset valueForKey:@"filename"]

iOS8 Photos Framework：如何获取 PHAsset 的名称（或文件名）？

iOS8 Photos Framework: How to get the name(or filename) of a PHAsset?

ios

phasset