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UIImageViews 之一时能够将图像保存到他们的照片库中。我喜欢 Safari 处理此问题的方式：您只需点击并按住直到出现弹出菜单，然后单击保存图像。我知道有“UIImageWriteToSavedPhotosAlbum”。但我是 iOS 开发的新手，我不太确定该去哪里以及把它放在哪里（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 而不是UIImageView。我是否需要将我的视图转换为UIImage？如果是这样，怎么做？如何检测用户何时点击图像，以及点击了哪个UIImageView？如果你能指出我正确的方向，也许还有一些例子，我将不胜感激。
【问题讨论】：
标签： iphone xcode ipad uiimageview photolibrary
您可以使用UIImageView 的image 属性来获取当前图像：
UIImage* imageToSave = [imageView image]; // alternatively, imageView.image
// Save it to the camera roll / saved photo album
UIImageWriteToSavedPhotosAlbum(imageToSave, nil, nil, nil);
【讨论】：
-(void)touchedImageView:(id)sender，在这种情况下为@987654326 @ 将是被触摸的视图。从那里，您可以显示一个菜单（例如UIActionSheet）来决定是否保存图像。
关于您的问题中询问如何检测哪个 UIImageView 被点击的部分，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.
}
}
【讨论】：
- (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];
}
【讨论】：
在 Swift 中：
// 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.
}
}
【讨论】：