如何将图片保存到iPhone照片库？

在Swift 2.2中。

UIImageWriteToSavedPhotosAlbum(image: UIImage, _ completionTarget: AnyObject?, _ completionSelector: Selector, _ contextInfo: UnsafeMutablePointer<Void>)

如果您不想在图像保存完成时收到通知，则可以在 completionTarget、completionSelector 和 contextInfo 参数中传递 nil。
示例：

UIImageWriteToSavedPhotosAlbum(image, self, #selector(self.imageSaved(_:didFinishSavingWithError:contextInfo:)), nil)

func imageSaved(image: UIImage!, didFinishSavingWithError error: NSError?, contextInfo: AnyObject?) {
        if (error != nil) {
            // Something wrong happened.
        } else {
            // Everything is alright.
        }
    }

重要的是注意到，你观察图像保存的方法应该有这三个参数，否则你会遇到NSInvocation错误。
希望对你有所帮助。

我的上一个回答就可以解决这个问题。

对于每个想要保存的图像，将其添加到NSMutableArray中。

    //in the .h file put:

NSMutableArray *myPhotoArray;


///then in the .m

- (void) viewDidLoad {

 myPhotoArray = [[NSMutableArray alloc]init];



}

//However Your getting images

- (void) someOtherMethod { 

 UIImage *someImage = [your prefered method of using this];
[myPhotoArray addObject:someImage];

}

-(void) saveMePlease {

//Loop through the array here
for (int i=0:i<[myPhotoArray count]:i++){
         NSString *file = [myPhotoArray objectAtIndex:i];
         NSString *path = [get the path of the image like you would in DOCS FOLDER or whatever];
         NSString *imagePath = [path stringByAppendingString:file];
         UIImage *image = [[[UIImage alloc] initWithContentsOfFile:imagePath]autorelease];

         //Now it will do this for each photo in the array
         UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
        }
}

我为此创建了一个UIImageView类别，基于上面一些答案。
头文件：

@interface UIImageView (SaveImage) <UIActionSheetDelegate>
- (void)addHoldToSave;
@end

实现

@implementation UIImageView (SaveImage)
- (void)addHoldToSave{
    UILongPressGestureRecognizer* longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
    longPress.minimumPressDuration = 1.0f;
    [self addGestureRecognizer:longPress];
}

-  (void)handleLongPress:(UILongPressGestureRecognizer*)sender {
    if (sender.state == UIGestureRecognizerStateEnded) {

        UIActionSheet* _attachmentMenuSheet = [[UIActionSheet alloc] initWithTitle:nil
                                                                          delegate:self
                                                                 cancelButtonTitle:@"Cancel"
                                                            destructiveButtonTitle:nil
                                                                 otherButtonTitles:@"Save Image", nil];
        [_attachmentMenuSheet showInView:[[UIView alloc] initWithFrame:self.frame]];
    }
    else if (sender.state == UIGestureRecognizerStateBegan){
        //Do nothing
    }
}
-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{
    if  (buttonIndex == 0) {
        UIImageWriteToSavedPhotosAlbum(self.image, nil,nil, nil);
    }
}


@end

现在只需在您的ImageView上调用此函数：

[self.imageView addHoldToSave];

你可以选择更改minimumPressDuration参数。

你可以使用这个

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
   UIImageWriteToSavedPhotosAlbum(img.image, nil, nil, nil);
});

对于 Swift 5.0

我使用以下代码将图片复制到应用程序创建的照片库中； 当我想要复制图像文件时，我调用“startSavingPhotoAlbume()”函数。 首先，我从应用程序文件夹获取UIImage，然后将其保存到照片库中。 因为这不相关，所以我不展示如何从应用程序文件夹中读取图像。

var saveToPhotoAlbumCounter = 0



func startSavingPhotoAlbume(){
    saveToPhotoAlbumCounter = 0
    saveToPhotoAlbume()
}

func saveToPhotoAlbume(){  
    let image = loadImageFile(fileName: imagefileList[saveToPhotoAlbumCounter], folderName: folderName)
    UIImageWriteToSavedPhotosAlbum(image!, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
}

@objc func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
    if (error != nil) {
        print("ptoto albume savin error for \(imageFileList[saveToPhotoAlbumCounter])")
    } else {
        
        if saveToPhotoAlbumCounter < imageFileList.count - 1 {
            saveToPhotoAlbumCounter += 1
            saveToPhotoAlbume()
        } else {
            print("saveToPhotoAlbume is finished with \(saveToPhotoAlbumCounter) files")
        }
    }
}