我正在尝试以编程方式截取视网膜屏幕截图,并且我已经尝试了在网上找到的所有方法,但我无法将屏幕截图变成视网膜。
我了解以下私有 API:
UIGetScreenImage();
不能使用,因为 Apple 会拒绝您的应用。但是,此方法返回的正是我需要的(屏幕的 640x960 屏幕截图)。
我已经在我的 iPhone 4 以及视网膜硬件上的 iPhone 4 模拟器上尝试过这种方法,但生成的图像始终是 320x480。
-(UIImage *)captureView
{
AppDelegate *appdelegate = [[UIApplication sharedApplication]delegate];
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)])
UIGraphicsBeginImageContextWithOptions(appdelegate.window.bounds.size, NO, 0.0);
else
UIGraphicsBeginImageContext(appdelegate.window.bounds.size);
[appdelegate.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSLog(@"SIZE: %@", NSStringFromCGSize(image.size));
NSLog(@"scale: %f", [UIScreen mainScreen].scale);
return image;
}
我也尝试过苹果推荐的方式:
- (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();
NSLog(@"Size: %@", NSStringFromCGSize(image.size));
return image;
}
但它也返回非视网膜图像:2012-12-23 19:57:45.205 PostCard[3351:707] size: {320, 480}
我有什么明显的遗漏吗?怎么会有假设采取视网膜屏幕截图的方法返回非视网膜屏幕截图?提前致谢!