如何在UIView上截取屏幕截图？

Question

如何在UIView上截取屏幕截图？

139

我想知道我的iPhone应用如何将特定的UIView作为UIImage截屏。

我尝试了这段代码，但我得到的只是一个空白图片。

UIGraphicsBeginImageContext(CGSizeMake(320,480));
CGContextRef context = UIGraphicsGetCurrentContext();
[myUIView.layer drawInContext:context];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

myUIView的尺寸为320x480，并且它有一些子视图。正确的做法是什么？

- cduck

只需查看 https://dev59.com/QnI95IYBdhLWcg3wsQBm#44517922 - Meet Doshi

16个回答

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- anthonyqz · Answer 1

我创建了这个扩展程序，可以从UIView中保存截图。

extension UIView {
func saveImageFromView(path path:String) {
    UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.mainScreen().scale)
    drawViewHierarchyInRect(bounds, afterScreenUpdates: true)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    UIImageJPEGRepresentation(image, 0.4)?.writeToFile(path, atomically: true)

}}

调用:

let pathDocuments = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).first!
let pathImage = "\(pathDocuments)/\(user!.usuarioID.integerValue).jpg"
reportView.saveImageFromView(path: pathImage)

如果您想创建一个png文件，必须进行以下更改：

UIImageJPEGRepresentation(image, 0.4)?.writeToFile(path, atomically: true)

by

UIImagePNGRepresentation(image)?.writeToFile(path, atomically: true)

- Ankit Kumar Gupta · Answer 2

Swift 4更新：

extension UIView {
   var screenShot: UIImage?  {
        if #available(iOS 10, *) {
            let renderer = UIGraphicsImageRenderer(bounds: self.bounds)
            return renderer.image { (context) in
                self.layer.render(in: context.cgContext)
            }
        } else {
            UIGraphicsBeginImageContextWithOptions(bounds.size, false, 5);
            if let _ = UIGraphicsGetCurrentContext() {
                drawHierarchy(in: bounds, afterScreenUpdates: true)
                let screenshot = UIGraphicsGetImageFromCurrentImageContext()
                UIGraphicsEndImageContext()
                return screenshot
            }
            return nil
        }
    }
}

- Jayprakash Dubey · Answer 3

下面的代码片段用于截屏：

UIGraphicsBeginImageContext(self.muUIView.bounds.size);

[myUIView.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

使用renderInContext:方法代替drawInContext:方法

renderInContext:方法将接收器及其子层渲染到当前上下文中。该方法直接从图层树中进行渲染。

- Ayush Goel · Answer 4

-(UIImage *)convertViewToImage
{
    UIGraphicsBeginImageContext(self.bounds.size);
    [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:YES];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

  return image;
}

- Vishwas Singh · Answer 5

你可以使用以下的UIView类别 -

@implementation UIView (SnapShot)

 - (UIImage *)snapshotImage
{
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);        
    [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:NO];        
    // old style [self.layer renderInContext:UIGraphicsGetCurrentContext()];        
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();        
    UIGraphicsEndImageContext();        
    return image;
}    
@end

- Azade Rahmati · Answer 6

 // MARK: - Actions
 @objc func imageWasSaved(_ image: UIImage, error: Error?, context: UnsafeMutableRawPointer) {
     if let error = error {
         print(error.localizedDescription)
         return
     }

     print("Image was saved in the photo gallery")
     UIApplication.shared.open(URL(string:"photos-redirect://")!)
 }
   
 func takeScreenshot(of view: UIView) {
     
     let bounds = UIScreen.main.bounds
     UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.main.scale)

     self.view.drawHierarchy(in: self.view.bounds, afterScreenUpdates: true)

        let screenshot = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
     UIImageWriteToSavedPhotosAlbum(screenshot, self, #selector(imageWasSaved), nil)
 }