保存图片、视频到相册

iOS 11 新增了“ Privacy - Photo Library Additions Usage Description ”权限

而 iOS10 及以前（换句话说也就是 XCODE8 及以前打包的 APP ）的照片权限（“ Privacy - Photo Library Usage Description ”）根本没有“永不”，“仅添加照片”，“读取和写入”的三个区分。

Info.plist 加入权限

<key>NSPhotoLibraryAddUsageDescription</key>
<string>App需要您的同意,才能保存相册</string>

保存图片
swift 4.0

    //MARK:- save image
    func WM_FUNC_saveImage(_ image:UIImage) -> Void {
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
    }
@objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
    if let error = error {
        // we got back an error!
        let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        present(ac, animated: true)
    } else {
        let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        present(ac, animated: true)
    }
}

OC

 //image是要保存的图片
- (void) saveImage:(UIImage *)image{
    if (image) {
        UIImageWriteToSavedPhotosAlbum(image, self, @selector(savedPhotoImage:didFinishSavingWithError:contextInfo:), nil);
    };
}
//保存完成后调用的方法
- (void) savedPhotoImage:(UIImage*)image didFinishSavingWithError: (NSError *)error contextInfo: (void *)contextInfo {
    if (error) {
        NSLog(@"save error%@", error.localizedDescription);
    }
    else {
        NSLog(@"save success");
    }
}

保存视频
swift4.0

 //MARK:- save video
    func WM_FUNC_saveVideo(_ urlStr:String) -> Void {
        UISaveVideoAtPathToSavedPhotosAlbum(urlStr, self, #selector(videoSaveStatus(_:didFinishSavingWithError:contextInfo:)), nil)
    }
    @objc func videoSaveStatus(_ urlstr: String, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer){
       if error != nil {
       //error
       }else{
       //success
       }
    }

oc

//videoPath为视频下载到本地之后的本地路径 URL.path
- (void)saveVideo:(NSString *)videoPath{
    if (_videoPath) {
            if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum([_videoPath path])) {
                //保存相册核心代码
                UISaveVideoAtPathToSavedPhotosAlbum([_videoPath path], self, @selector(video:didFinishSavingWithError:contextInfo:), nil);
            }
    }
}
//保存视频完成之后的回调
- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    if (error) {
        NSLog(@"save error%@", error.localizedDescription);
    }
    else {
        NSLog(@"save success");
    }
}