如何在swift中在相機上添加圓形蒙版

Question

現在我是新手，但我想學習如何在swift中添加圓形蒙版。 現在我正在使用Xcode7.2.1，swift 2.1，但我不知道這一點。 而我正在開發這款相機應用程序，它使用https://github.com/imaginary-cloud/CameraManager作爲第三方庫。 在這裏，我想添加我的自定義圓形面具在相機上。 我在想誰能幫我弄到這個！ 感謝

Answer 1

UIImagePickerController有你可以用它來提供，這將作爲一個覆蓋一個自定義視圖的cameraOverlayView財產。下面的示例創建一個正方形的疊加視圖。試用它來獲得你想要的。

@IBAction func takePhoto(sender: AnyObject) { 

    if !UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera){ 
     return 
    } 

    var imagePicker = UIImagePickerController() 
    imagePicker.delegate = self 
    imagePicker.sourceType = UIImagePickerControllerSourceType.Camera; 

    //Create camera overlay 
    let pickerFrame = CGRectMake(0, UIApplication.sharedApplication().statusBarFrame.size.height, imagePicker.view.bounds.width, imagePicker.view.bounds.height - imagePicker.navigationBar.bounds.size.height - imagePicker.toolbar.bounds.size.height) 
    let squareFrame = CGRectMake(pickerFrame.width/2 - 200/2, pickerFrame.height/2 - 200/2, 200, 200) 
    UIGraphicsBeginImageContext(pickerFrame.size) 

    let context = UIGraphicsGetCurrentContext() 
    CGContextSaveGState(context) 
    CGContextAddRect(context, CGContextGetClipBoundingBox(context)) 
    CGContextMoveToPoint(context, squareFrame.origin.x, squareFrame.origin.y) 
    CGContextAddLineToPoint(context, squareFrame.origin.x + squareFrame.width, squareFrame.origin.y) 
    CGContextAddLineToPoint(context, squareFrame.origin.x + squareFrame.width, squareFrame.origin.y + squareFrame.size.height) 
    CGContextAddLineToPoint(context, squareFrame.origin.x, squareFrame.origin.y + squareFrame.size.height) 
    CGContextAddLineToPoint(context, squareFrame.origin.x, squareFrame.origin.y) 
    CGContextEOClip(context) 
    CGContextMoveToPoint(context, pickerFrame.origin.x, pickerFrame.origin.y) 
    CGContextSetRGBFillColor(context, 0, 0, 0, 1) 
    CGContextFillRect(context, pickerFrame) 
    CGContextRestoreGState(context) 

    let overlayImage = UIGraphicsGetImageFromCurrentImageContext() 
    UIGraphicsEndImageContext(); 

    let overlayView = UIImageView(frame: pickerFrame) 
    overlayView.image = overlayImage 
    imagePicker.cameraOverlayView = overlayView 
    self.presentViewController(imagePicker, animated: true, completion: nil) 

}