Question

我正在创建一个iPad应用程序，它在水平滚动视图中有几张图片（UIImageViews）。我想让用户在点击其中一个UIImageView时能够将图像保存到他们的照片库中。我喜欢Safari处理这个问题的方式：你只需点击并按住直到弹出菜单出现，然后点击保存图像。我知道有“UIImageWriteToSavedPhotosAlbum”。但我是iOS开发的新手，我不太清楚在哪里使用它以及放置它（即如何检测哪个图像被点击）。

根据我的发现，我看到人们使用UIImage代替UIImageView。我是否需要将观看次数转换为UIImage？如果是这样，怎么样？如何检测用户何时点按图片以及点击了哪个UIImageView？如果你可以指出我正确的方向，也许一些例子我会非常感激。

Answer 1

您可以使用image的{{1}}属性来获取当前图片：

UIImageView

Answer 2

- (IBAction)TakePicture:(id)sender {


    // Create image picker controller
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

    // Set source to the camera
    imagePicker.sourceType =  UIImagePickerControllerSourceTypeCamera;


    // Delegate is self
    imagePicker.delegate = self;


    OverlayView *overlay = [[OverlayView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGTH)];

   // imagePicker.cameraViewTransform = CGAffineTransformScale(imagePicker.cameraViewTransform, CAMERA_TRANSFORM_X, CAMERA_TRANSFORM_Y);

    // Insert the overlay:
    imagePicker.cameraOverlayView = overlay;

   // Allow editing of image ?
    imagePicker.allowsImageEditing = YES;
    [imagePicker setCameraDevice:
     UIImagePickerControllerCameraDeviceFront];
    [imagePicker setAllowsEditing:YES];
    imagePicker.showsCameraControls=YES;
    imagePicker.navigationBarHidden=YES;
    imagePicker.toolbarHidden=YES;
    imagePicker.wantsFullScreenLayout=YES;


    self.library = [[ALAssetsLibrary alloc] init];


    // Show image picker
    [self presentModalViewController:imagePicker animated:YES];
}





- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    // Access the uncropped image from info dictionary
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];




    // Save image to album
    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);


    // save image to custom album
    [self.library saveImage:image toAlbum:@"custom name" withCompletionBlock:^(NSError *error) {
        if (error!=nil) {
            NSLog(@"Big error: %@", [error description]);
        }
    }];

    [picker dismissModalViewControllerAnimated:NO];


}



- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    UIAlertView *alert;

    // Unable to save the image  
    if (error)
        alert = [[UIAlertView alloc] initWithTitle:@"Error" 
                                           message:@"Unable to save image to Photo Album." 
                                          delegate:self cancelButtonTitle:@"Ok" 
                                 otherButtonTitles:nil];
    else // All is well
        alert = [[UIAlertView alloc] initWithTitle:@"Success" 
                                           message:@"Image saved to Photo Album." 
                                          delegate:self cancelButtonTitle:@"Ok" 
                                 otherButtonTitles:nil];


    [alert show];
}



- (void) alertView:(UIAlertView *)alert clickedButtonAtIndex:(NSInteger)buttonIndex
{
    // After saving iamge, dismiss camera
    [self dismissModalViewControllerAnimated:YES];
}

Answer 3

关于询问如何检测哪个UIImageView被点击的问题部分，您可以使用如下代码：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{

 [super touchesEnded:touches withEvent:event];
 UITouch *touch = [touches anyObject];
 CGPoint touchEndpoint = [touch locationInView:self.view]; 
 CGPoint imageEndpoint = [touch locationInView:imageview];
 if(CGRectContainsPoint([imageview frame], touchEndpoint))
 {
 do here any thing after touch the event.

  }
}

Answer 4

在 Swift ：

    // Save it to the camera roll / saved photo album
    // UIImageWriteToSavedPhotosAlbum(self.myUIImageView.image, nil, nil, nil) or 
    UIImageWriteToSavedPhotosAlbum(self.myUIImageView.image, self, "image:didFinishSavingWithError:contextInfo:", nil)

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

将UIImageView中的图像保存到iPad照片库

4 个答案: