Question

我正在开发一款iOs 5 iPhone应用程序，当用户按下故事板中某个视图的按钮时，我想以编程方式截取屏幕截图。我尝试了很多代码，但它们适用于旧版本的iOs。我怎样才能在iOs 5中做到这一点。谢谢!!

Answer 1

- (void)drawRect:(CGRect)rect {   
     UIGraphicsBeginImageContext(self.bounds.size);
     [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
     UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();  
     UIGraphicsEndImageContext();   
}

Answer 2

嗯，以编程方式捕捉iPhone屏幕的方法很少

使用UIKIT http://developer.apple.com/library/ios/#qa/qa1703/_index.html
使用AVFoundation框架http://developer.apple.com/library/ios/#qa/qa1702/_index.html
使用OpenGL ES http://developer.apple.com/library/ios/#qa/qa1704/_index.html

使用视图

CGRect screenRect = [[UIScreen mainScreen] bounds];
UIGraphicsBeginImageContext(screenRect.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, screenRect);
[self.window.layer renderInContext:ctx];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

使用窗口

UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viImage=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

在这5种方法中，我发现第一个选项非常便于复制粘贴和应用压缩级别，因为第一种方法为图像提供了真实的像素数据。

Answer 3

由于这是一个老问题，我把代码放在这里，希望有人帮忙。（代码是Apple的副本：http://developer.apple.com/library/ios/#qa/qa1703/_index.html）

- (UIImage*)screenshot 
{
    // Create a graphics context with the target size
    // On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration
    // On iOS prior to 4, fall back to use UIGraphicsBeginImageContext
    CGSize imageSize = [[UIScreen mainScreen] bounds].size;
    if (NULL != UIGraphicsBeginImageContextWithOptions)
        UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
    else
        UIGraphicsBeginImageContext(imageSize);

    CGContextRef context = UIGraphicsGetCurrentContext();

    // 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);
            // 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
            [[window layer] renderInContext:context];

            // Restore the context
            CGContextRestoreGState(context);
        }
    }

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

    UIGraphicsEndImageContext();

    return image;
}

以编程方式截取iOs 5

3 个答案: