iOS 在當前設備顯示而不是應用屏幕上截圖

Question

我有這些代碼（用 C# 編寫）來截取屏幕截圖，但它只截取 App Screen，即使我最小化我的應用程序，它仍然會捕獲我的 App 屏幕。 我想占據整個設備屏幕，即使我打開另一個應用程序，它也會顯示其他應用程序、桌面等的屏幕截圖......

在 C# Xamarin

var view = UIApplication.SharedApplication.KeyWindow.RootViewController.View;

UIGraphics.BeginImageContext(view.Frame.Size);
view.DrawViewHierarchy(view.Frame, true);
var image = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();

using (var imageData = image.AsPNG())
{
    var bytes = new byte[imageData.Length];
    System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, bytes, 0, Convert.ToInt32(imageData.Length));
    return bytes;
}

你也可以在 Swift/Objective-C 中發布建議。

Answer 1

不幸的是，這是不可能的。 出於安全原因，iOS 不允許應用程序截取除它們自己的視圖層次結構之外的任何內容。

更新：澄清一下，在您的應用程序中獲取其他應用程序屏幕截圖的唯一方法是讓用戶手動截取屏幕截圖（使用主頁 + 電源按鈕），然后讓用戶將其發送/共享到您的應用程序（通過支持和處理圖像文件類型），或者讓用戶從他們的照片庫中選擇它（使用UIImagePickerController ）。

目前沒有選項可以完全自動化此過程。

Answer 2

在您的情況下，您應該使用UIScreen的View而不是當前的ViewController 。

CGSize size = UIScreen.MainScreen.Bounds.Size;
nfloat scale = UIScreen.MainScreen.Scale;

UIGraphics.BeginImageContextWithOptions(size,true,scale);
           UIApplication.SharedApplication.KeyWindow.Layer.RenderInContext(UIGraphics.GetCurrentContext());

UIImage image = UIGraphics.GetImageFromCurrentImageContext();

UIGraphics.EndImageContext();

如果你想讓屏幕截圖包含狀態欄，你可以參考下面的 OC 代碼

+ (UIImage *)screenshotWithStatusBar:(BOOL)withStatusBar rect:(CGRect)rect
{
    UIInterfaceOrientation o = [[UIApplication sharedApplication] statusBarOrientation];
    return [self screenshotWithStatusBar:withStatusBar rect:rect orientation:o];
}

+ (UIImage *)screenshotWithStatusBar:(BOOL)withStatusBar rect:(CGRect)rect orientation:(UIInterfaceOrientation)o
{
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = CGRectGetWidth(screenRect);
    CGFloat screenHeight = CGRectGetHeight(screenRect);
    CGAffineTransform preTransform = CGAffineTransformIdentity;
    switch (o)
    {
        case UIInterfaceOrientationPortrait:
            //move screenshot rect origin to down left
            //rotate screenshot rect to meet portrait
            //move screenshot rect origin to up left
            //....yes, with a single line..
            preTransform = CGAffineTransformTranslate(preTransform, -rect.origin.x, -rect.origin.y);
            break;
        case UIInterfaceOrientationPortraitUpsideDown:
            //move screenshot rect origin to down left
            preTransform = CGAffineTransformTranslate(preTransform, screenWidth - rect.origin.x, -rect.origin.y);
            //rotate screenshot rect to meet portrait
            preTransform = CGAffineTransformRotate(preTransform, M_PI);
            //move screenshot rect origin to up left
            preTransform = CGAffineTransformTranslate(preTransform, 0, -screenHeight);
            break;
        case UIInterfaceOrientationLandscapeLeft:
            //move screenshot rect origin to down left
            preTransform = CGAffineTransformTranslate(preTransform, -rect.origin.x, -rect.origin.y);
            //rotate screenshot rect to meet portrait
            preTransform = CGAffineTransformRotate(preTransform, M_PI_2);
            //move screenshot rect origin to up left
            preTransform = CGAffineTransformTranslate(preTransform, 0, -screenHeight);
            break;
        case UIInterfaceOrientationLandscapeRight:
            //move screenshot rect origin to down left
            preTransform = CGAffineTransformTranslate(preTransform, screenHeight - rect.origin.x, screenWidth - rect.origin.y);
            //rotate screenshot rect to meet portrait
            preTransform = CGAffineTransformRotate(preTransform, - M_PI_2);
            //move screenshot rect origin to up left
            preTransform = CGAffineTransformTranslate(preTransform, 0, -screenHeight);
            break;
        default:
            break;
    }

    // Create a graphics context with the target size
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);

    CGContextRef context = UIGraphicsGetCurrentContext();

    BOOL hasTakenStatusBarScreenshot = NO;
    // Iterate over every window from back to front
    for (UIWindow *window in [[UIApplication sharedApplication] windows])
    {
        if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
        {
            // -renderInContext: renders in the coordinate space of the layer,
            // so we must first apply the layer's geometry to the graphics context
            CGContextSaveGState(context);

            // Apply pre tranform to context.
            // to convert all interface orientation situation to portrait situation.
            CGContextConcatCTM(context, preTransform);
            // Center the context around the window's anchor point
            CGContextTranslateCTM(context, [window center].x, [window center].y);
            // Apply the window's transform about the anchor point
            CGContextConcatCTM(context, [window transform]);
            // Offset by the portion of the bounds left of and above the anchor point
            CGContextTranslateCTM(context,
                                  -[window bounds].size.width * [[window layer] anchorPoint].x,
                                  -[window bounds].size.height * [[window layer] anchorPoint].y);


            // Render the layer hierarchy to the current context
            if ([window respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
                [window drawViewHierarchyInRect:window.bounds afterScreenUpdates:YES];
            } else {
                [window.layer renderInContext:context];
            }

            // Restore the context
            CGContextRestoreGState(context);
        }

        // Screenshot status bar if next window's window level > status bar window level
        NSArray *windows = [[UIApplication sharedApplication] windows];
        NSUInteger currentWindowIndex = [windows indexOfObject:window];
        if (windows.count > currentWindowIndex + 1)
        {
            UIWindow *nextWindow = [windows objectAtIndex:currentWindowIndex + 1];
            if (withStatusBar && nextWindow.windowLevel > UIWindowLevelStatusBar && !hasTakenStatusBarScreenshot)
            {
                [self mergeStatusBarToContext:context rect:rect screenshotOrientation:o];
                hasTakenStatusBarScreenshot = YES;
            }
        }
        else
        {
            if (withStatusBar && !hasTakenStatusBarScreenshot)
            {
                [self mergeStatusBarToContext:context rect:rect screenshotOrientation:o];
                hasTakenStatusBarScreenshot = YES;
            }
        }
    }

    // Retrieve the screenshot image
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;
}

+ (void)mergeStatusBarToContext:(CGContextRef)context
                           rect:(CGRect)rect
          screenshotOrientation:(UIInterfaceOrientation)o
{
    UIView *statusBarView = [UIView statusBarInstance_ComOpenThreadOTScreenshotHelper];
    UIInterfaceOrientation statusBarOrientation = [[UIApplication sharedApplication] statusBarOrientation];
    CGFloat screenWidth = [[UIScreen mainScreen] bounds].size.width;
    CGFloat screenHeight = [[UIScreen mainScreen] bounds].size.height;
    CGAffineTransform preTransform = CGAffineTransformIdentity;
    if (o == statusBarOrientation)
    {
        preTransform = CGAffineTransformTranslate(preTransform, -rect.origin.x, -rect.origin.y);
    }
    //Handle status bar orientation in portrait and portrait upside down screen shot
    else if((o == UIInterfaceOrientationPortrait && statusBarOrientation == UIInterfaceOrientationLandscapeLeft) ||
            (o == UIInterfaceOrientationPortraitUpsideDown && statusBarOrientation == UIInterfaceOrientationLandscapeRight))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, - M_PI_2);
        preTransform = CGAffineTransformTranslate(preTransform, CGRectGetMaxY(rect) - screenHeight, -rect.origin.x);
    }
    else if((o == UIInterfaceOrientationPortrait && statusBarOrientation == UIInterfaceOrientationLandscapeRight) ||
            (o == UIInterfaceOrientationPortraitUpsideDown && statusBarOrientation == UIInterfaceOrientationLandscapeLeft))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, M_PI_2);
        preTransform = CGAffineTransformTranslate(preTransform, -CGRectGetMaxY(rect), rect.origin.x - screenWidth);
    }
    else if((o == UIInterfaceOrientationPortrait && statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown) ||
            (o == UIInterfaceOrientationPortraitUpsideDown && statusBarOrientation == UIInterfaceOrientationPortrait))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, - M_PI);
        preTransform = CGAffineTransformTranslate(preTransform, rect.origin.x - screenWidth, CGRectGetMaxY(rect) - screenHeight);
    }
    //Handle status bar orientation in landscape left and landscape right screen shot
    else if((o == UIInterfaceOrientationLandscapeLeft && statusBarOrientation == UIInterfaceOrientationPortrait) ||
            (o == UIInterfaceOrientationLandscapeRight && statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, M_PI_2);
        preTransform = CGAffineTransformTranslate(preTransform, -CGRectGetMaxY(rect), rect.origin.x - screenHeight);
    }
    else if((o == UIInterfaceOrientationLandscapeLeft && statusBarOrientation == UIInterfaceOrientationLandscapeRight) ||
            (o == UIInterfaceOrientationLandscapeRight && statusBarOrientation == UIInterfaceOrientationLandscapeLeft))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, M_PI);
        preTransform = CGAffineTransformTranslate(preTransform, rect.origin.x - screenHeight, CGRectGetMaxY(rect) - screenWidth);
    }
    else if((o == UIInterfaceOrientationLandscapeLeft && statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown) ||
            (o == UIInterfaceOrientationLandscapeRight && statusBarOrientation == UIInterfaceOrientationPortrait))
    {
        preTransform = CGAffineTransformTranslate(preTransform, 0, rect.size.height);
        preTransform = CGAffineTransformRotate(preTransform, - M_PI_2);
        preTransform = CGAffineTransformTranslate(preTransform, CGRectGetMaxY(rect) - screenWidth, -rect.origin.x);
    }

    // -renderInContext: renders in the coordinate space of the layer,
    // so we must first apply the layer's geometry to the graphics context
    CGContextSaveGState(context);
    // Apply pre transform
    CGContextConcatCTM(context, preTransform);
    // Center the context around the window's anchor point
    CGContextTranslateCTM(context, [statusBarView center].x, [statusBarView center].y);
    // Apply the view transform about the anchor point
    CGContextConcatCTM(context, [statusBarView transform]);
    // Offset by the portion of the bounds left of and above the anchor point
    CGContextTranslateCTM(context,
                          -[statusBarView bounds].size.width * [[statusBarView layer] anchorPoint].x,
                          -[statusBarView bounds].size.height * [[statusBarView layer] anchorPoint].y);

    // Render the layer hierarchy to the current context
    if ([statusBarView respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
        [statusBarView drawViewHierarchyInRect:statusBarView.bounds afterScreenUpdates:YES];
    } else {
        [statusBarView.layer renderInContext:context];
    }

    // Restore the context
    CGContextRestoreGState(context);
}