UIImagePickerController AllowsEditing not working

问题:

I am using UIImagePickerController to allow the user to take a picture. I want to allow him to edit it afterwards but whatever I am doing i get nothing. Here is my code (I am using Xamarin):

UIImagePickerController imagePicker = new UIImagePickerController ();
                // set our source to the camera
                imagePicker.SourceType = UIImagePickerControllerSourceType.Camera;
                // set what media types
                //imagePicker.MediaTypes = UIImagePickerController.AvailableMediaTypes (UIImagePickerControllerSourceType.Camera);
                // show the camera controls
                imagePicker.ModalPresentationStyle = UIModalPresentationStyle.CurrentContext;
                imagePicker.ShowsCameraControls = true;
                imagePicker.AllowsEditing = true;
                imagePicker.SetEditing (true,true);
                imagePicker.PreferredContentSize = new SizeF(900,600);
                imagePicker.CameraCaptureMode = UIImagePickerControllerCameraCaptureMode.Photo;
                imagePicker.Title="taste.eat. image";
                // attach the delegate
                imagePicker.Delegate = new ImagePickerDelegate();
                // show the picker
                NavigationController.PresentViewController(imagePicker, true,null);

Am I missing something?

EDIT:

I have followed the tutorial and I am getting to the screen with the rectangle, but if i pan or zoom it just snaps back to the center once I lift my finger. Is it possible to get to this screen from the photos application?

回答1:

When using UIImagePickerController's delegate -imagePickerController:didFinishPickingMediaWithInfo: ,we get the image using

UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

This code will always return the original image, even if editing is ON.

Try using

UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];

This will return the edited image if editing is ON.

Hope this helps.

回答2:

The AllowsEditing property simply allows the user to crop to a square if picking an image and trim the video if picking a video.

Any other functionality needs to be implemented with custom UI and code.

See this question:iPhone SDK - How to customize the crop rect in UIImagePickerController with allowsEditing on?

What you are showing in the screenshot is not part of UIImagePickerController, unfortunately

回答3:

SWIFT 3

I was having a hard time returning the cropped image (simple mistake on my end). Instead of using UIImagePickerControllerOriginalImage, you need UIImagePickerControllerEditedImage. See below:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    // The info dictionary contains multiple representations of the image, and this uses the cropped image.
    let selectedImage = info[UIImagePickerControllerEditedImage] as! UIImage

    // Set yourImageView to display the selected image.
    yourImage.image = selectedImage

    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

回答4:

It will be work like this way.

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    let selectedImage = info[UIImagePickerControllerEditedImage] as! UIImage

    userPhoto.image = selectedImage

    dismiss(animated: true, completion: nil)
}

回答5:

There is no way to enable filters by just changing property like allowsEditing = YES. It will only display a cropping tool. As per your screenshot it's look like you have integrated some buggy open source library and without looking at the source code it would be difficult to fix your center cropping bug.

Better to post some concrete detail about your implementation or switch to standard open source library.