iOS下将照片保存到相册的三种方法

方法一

使用UIImageWriteToSavedPhotosAlbum函数将图片保存到相册，如：

- (void)loadImageFinished:(UIImage *)image{    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), (__bridge void *)self);}- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{    NSLog(@"image = %@, error = %@, contextInfo = %@", image, error, contextInfo);}

方法二

使用AssetsLibrary框架中的ALAssetsLibrary类来实现。具体代码如下：

- (void)loadImageFinished:(UIImage *)image{    __block ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];    [lib writeImageToSavedPhotosAlbum:image.CGImage metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {        NSLog(@"assetURL = %@, error = %@", assetURL, error);        lib = nil;    }];}

方法三

使用Photos框架的PHPhotoLibrary类来实现保存到相册功能。代码如下：

- (void)loadImageFinished:(UIImage *)image{    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{         /写入图片到相册         PHAssetChangeRequest *req = [PHAssetChangeRequest creationRequestForAssetFromImage:image];     } completionHandler:^(BOOL success, NSError * _Nullable error) {         NSLog(@"success = %d, error = %@", success, error);    }];}