在我的应用程序中,我希望用户能够拍照,呈现图片,并且通过点击照片可以添加文本字段,以便他们可以在图像上书写。这与在 Snapchat 中为图片添加文字的功能完全相同。
据我所知,在拍摄并能够编辑图像后呈现图像的唯一方法是设置:
imagePicker.showsCameraControls = false
制作自定义叠加层:
@IBAction func takePhoto(sender: UIButton) {
imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = .Camera
imagePicker.showsCameraControls = false
imagePicker.allowsEditing = true
let overlayView = UIView(frame: CGRectMake(0, self.view.frame.width, self.view.frame.width, self.view.frame.height-self.view.frame.width))
overlayView.backgroundColor = UIColor.blackColor()
overlayView.alpha = 0.5
println(overlayView)
let snapButton = UIView(frame: CGRectMake(150, 160, 80, 80))
snapButton.layer.cornerRadius = 40
snapButton.userInteractionEnabled = true
snapButton.backgroundColor = UIColor.purpleColor()
overlayView.addSubview(snapButton)
overlayView.bringSubviewToFront(snapButton)
let recognizer = UITapGestureRecognizer(target: self, action:Selector("handleSnapTap:"))
recognizer.delegate = self
snapButton.addGestureRecognizer(recognizer)
let cancelButton = UIView(frame: CGRectMake(40, 40, 44, 44))
cancelButton.layer.cornerRadius = 22
cancelButton.userInteractionEnabled = true
cancelButton.backgroundColor = UIColor.redColor()
overlayView.addSubview(cancelButton)
overlayView.bringSubviewToFront(cancelButton)
let cancelRecognizer = UITapGestureRecognizer(target: self, action:Selector("handleCancelTap:"))
cancelRecognizer.delegate = self
cancelButton.addGestureRecognizer(cancelRecognizer)
let changeCameraButton = UIView(frame: CGRectMake(165, 40, 44, 44))
changeCameraButton.layer.cornerRadius = 22
changeCameraButton.userInteractionEnabled = true
changeCameraButton.backgroundColor = UIColor.blueColor()
overlayView.addSubview(changeCameraButton)
overlayView.bringSubviewToFront(changeCameraButton)
let changeCameraRecognizer = UITapGestureRecognizer(target: self, action:Selector("handleChangeCameraTap:"))
changeCameraRecognizer.delegate = self
changeCameraButton.addGestureRecognizer(changeCameraRecognizer)
let flashButton = UIView(frame: CGRectMake(300, 40, 44, 44))
flashButton.layer.cornerRadius = 22
flashButton.userInteractionEnabled = true
flashButton.backgroundColor = UIColor.yellowColor()
overlayView.addSubview(flashButton)
overlayView.bringSubviewToFront(flashButton)
let flashRecognizer = UITapGestureRecognizer(target: self, action:Selector("handleFlashTap:"))
flashRecognizer.delegate = self
flashButton.addGestureRecognizer(flashRecognizer)
imagePicker.cameraOverlayView = overlayView
presentViewController(imagePicker, animated: true, completion: nil)
}
func handleSnapTap(recognizer: UITapGestureRecognizer) {
println("Take picture")
imagePicker.takePicture()
self.performSegueWithIdentifier("cameraToImageViewSegue", sender: self)
}
func handleCancelTap(recognizer: UITapGestureRecognizer) {
println("Cancel")
self.imagePicker.dismissViewControllerAnimated(true, completion: nil)
}
func handleChangeCameraTap(recognizer: UITapGestureRecognizer) {
if (hasChangedCamera == nil){
imagePicker.cameraDevice = UIImagePickerControllerCameraDevice.Front
hasChangedCamera = true
return
}
if (hasChangedCamera == true){
imagePicker.cameraDevice = UIImagePickerControllerCameraDevice.Rear
hasChangedCamera = false
return
}
if (hasChangedCamera! == false){
imagePicker.cameraDevice = UIImagePickerControllerCameraDevice.Front
hasChangedCamera = true
return
}
}
func handleFlashTap(recognizer: UITapGestureRecognizer) {
if (hasTurnedOnFlash == nil){
imagePicker.cameraFlashMode = UIImagePickerControllerCameraFlashMode.On
hasTurnedOnFlash = true
return
}
if (hasTurnedOnFlash == true){
imagePicker.cameraFlashMode = UIImagePickerControllerCameraFlashMode.Off
hasTurnedOnFlash = false
return
}
if (hasTurnedOnFlash == false){
imagePicker.cameraFlashMode = UIImagePickerControllerCameraFlashMode.On
hasTurnedOnFlash = true
return
}
}
最后呈现一个新的视图控制器,其中拾取的图像放置在 UIView 中,并从那里编辑它。我的问题是如何直接从 UIImagePickerController 到新的视图控制器。我尝试了以下方法:
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
self.imagePicker.dismissViewControllerAnimated(false, completion: nil)
let vc = ModifyCameraImageViewController() //change this to your class name
self.presentViewController(vc, animated: false, completion: nil)
}
首先,这只会导致黑屏,但我确信有一个足够简单的方法来解决这个问题。我的主要问题是,在下一个视图控制器出现之前,显示 UIImagePickerController 的视图控制器会短暂出现在屏幕上。这显然不好看。我还尝试删除dismissViewController 函数,以及将presentViewController 函数放在dismissView 控制器函数之上。这两种尝试都给了我错误信息:
Warning: Attempt to present <xxx.ModifyCameraImageViewController: 0x145e3eb70> on <xxx.ViewController: 0x145d20a60> whose view is not in the window hierarchy!
尝试将 performSegueWithIdentifier 与链接底层视图和下一个视图控制器的 segue 一起使用会给出相同的错误警告。
我发现了以下类似的问题,但我对 Objective C 完全无能为力,所以我很难理解它:Push a viewController from the UIImagePickerController camera view
那么,任何人都可以就如何直接从 UIImagePickerController 呈现视图控制器提供帮助吗?
另外,请记住,我这样做是为了能够在新选择的图像上创建文本覆盖(如在 Snapchat 中),所以如果有人对此有更优雅的解决方案,请随时发布!
谢谢!