在url上保存图像时出现PHPhotoLibrary错误 [英] PHPhotoLibrary error while saving image at url

问题描述

我在 PHContentEditingOutput 提供的网址上创建了一个图片。当我将数据加载到 UIImage 并保存它时 - 它可以工作。

I create an image at url provided by PHContentEditingOutput. When I load data to UIImage and save it like this - it works.

[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
    NSData *data = [NSData dataWithContentsOfURL:contentEditingOutput.renderedContentURL]
    UIImage *image = [UIImage imageWithData:data];
    [PHAssetChangeRequest creationRequestForAssetFromImage:image];
} completionHandler:^(BOOL success, NSError *error) {
     ...
}];

但是当我尝试使用url时，它会失败：

But when I try approach with url it fails:

[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
    [PHAssetChangeRequest creationRequestForAssetFromImageAtFileURL:contentEditingOutput.renderedContentURL];
} completionHandler:^(BOOL success, NSError *error) {
     ...
}];

错误：

Error Domain = NSCocoaErrorDomain Code = -1无法完成操作。（Cocoa error -1。）

Error Domain=NSCocoaErrorDomain Code=-1 "The operation couldn’t be completed. (Cocoa error -1.)"

更新：

尝试保存修改时出现同样的错误。

The same error when I try to save a modification.

[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
    PHAssetChangeRequest *request = [PHAssetChangeRequest changeRequestForAsset:asset];
    request.contentEditingOutput = contentEditingOutput;
} completionHandler:^(BOOL success, NSError *error) {
     ...
}];

该方法适用于视频（ creationRequestForAssetFromVideoAtFileURL：），但不是图像。出了什么问题？

The method works for a video (creationRequestForAssetFromVideoAtFileURL:), but not for an image. What went wrong?

推荐答案

问题在于文件格式。我正在尝试修改 PNG 屏幕截图，但 renderingContentURL 始终是 tmp / filename。 JPG 。起初我认为这是一个错误，但根据文档这是正确的行为。

The problem is in the file format. I was trying to edit PNG screenshot, but renderingContentURL was always tmp/filename.JPG. At first I thought it was a bug, but according to the documentation this is correct behaviour.

阅读此属性以查找用于编写已编辑资产内容的URL。然后，如果编辑照片资产，请将更改后的照片图像写入此URL的JPEG格式文件。如果正在编辑视频资源，请将视频导出到此URL的QuickTime（.mov）文件。

Read this property to find a URL for writing edited asset content. Then, if editing a photo asset, write the altered photo image to a file in JPEG format at this URL. If editing a video asset, export the video to a QuickTime (.mov) file at this URL.

解决方案是转换具有功能的图像

The solution is to convert the image with function

NSData *UIImageJPEGRepresentation(UIImage *image, CGFloat compressionQuality);

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