ios - 捕获 UIView 并保存为图像

Question

首先我添加UILable，UIImageView然后在我截图之后UIView，图像没有正确捕获UIView框架我还附上了图像网址。

1）原图链接：

2）捕获图像链接后：

代码：

UIGraphicsBeginImageContext(viewImage.frame.size);
[viewImage.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *vwImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

NSData *data=UIImagePNGRepresentation(vwImage);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
// NSString *imgName = [NSString stringWithFormat:imagename];
NSString *strPath = [documentsDirectory stringByAppendingPathComponent:imagename];
[data writeToFile:strPath atomically:YES];

Answer 1

您可以截取任何屏幕截图UIView或捕获任何屏幕截图，UIView然后使用以下代码将其保存为图像。

- (UIImage *)captureView {

    //hide controls if needed
    CGRect rect = [self.view bounds];

    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [self.view.layer renderInContext:context];   
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return img;

}

Answer 2

拍摄 UIView 的快照

将您的视图传递给此函数，它将自行处理所有内容（无需设置边界或框架）

- (UIImage *)takeSnapshotOfView:(UIView *)view
{
    UIGraphicsBeginImageContext(CGSizeMake(view.frame.size.width, view.frame.size.height));
    [view drawViewHierarchyInRect:CGRectMake(0, 0, view.frame.size.width, view.frame.size.height) afterScreenUpdates:YES];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

Answer 3

斯威夫特 3 版本：

func takeSnapshotOfView(view:UIView) -> UIImage? {
    UIGraphicsBeginImageContext(CGSize(width: view.frame.size.width, height: view.frame.size.height))
    view.drawHierarchy(in: CGRect(x: 0.0, y: 0.0, width: view.frame.size.width, height: view.frame.size.height), afterScreenUpdates: true)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}

Answer 4

在 Swift 5 中作为扩展：

extension UIView {

    func takeSnapshot() -> UIImage? {
        UIGraphicsBeginImageContext(CGSize(width: self.frame.size.width, height: self.frame.size.height - 5))
        let rect = CGRect(x: 0.0, y: 0.0, width: self.frame.size.width, height: self.frame.size.height)
        drawHierarchy(in: rect, afterScreenUpdates: true)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

extension UIImage {

    func saveToPhotoLibrary(_ completionTarget: Any?, _ completionSelector: Selector?) {
        DispatchQueue.global(qos: .userInitiated).async {
            UIImageWriteToSavedPhotosAlbum(self, completionTarget, completionSelector, nil)
        }
    }
}

extension UIAlertController {

    func present() {
        guard let controller = UIApplication.shared.windows.filter({$0.isKeyWindow}).first?.rootViewController else {
            return
        }
        controller.present(self, animated: true)
    }
}

在您的UIView子类中：

func saveImage() {
    let selector = #selector(self.onImageSaved(_:error:contextInfo:))
    takeSnapshot()?.saveToPhotoLibrary(self, selector)
}

@objc private func onImageSaved(_ image: UIImage, error: Error?, contextInfo: UnsafeRawPointer) {
    if let error = error {
        let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        ac.present()
    } else {
        let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        ac.present()
    }
    onImageSaved?()
}

Answer 5

您可以使用以下代码

UIGraphicsBeginImageContext(pictureView.bounds.size); 
                    
[pictureView.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

Answer 6

像这样试试

UIGraphicsBeginImageContext(viewImage.frame.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, viewImage.frame);     

[viewImage.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *vwImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

NSData *data=UIImagePNGRepresentation(vwImage);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
// NSString *imgName = [NSString stringWithFormat:imagename];
NSString *strPath = [documentsDirectory stringByAppendingPathComponent:imagename];
[data writeToFile:strPath atomically:YES];

Answer 7

如果您希望捕获的图像保持其原始质量，请尝试此操作。

- (UIImage *)captureViewWithAllSubView:(UIView *)view {
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0f);
    [view drawViewHierarchyInRect:view.bounds afterScreenUpdates:YES];
    UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return capturedImage;
}