我试图采取视网膜屏幕截图编程和我都想尽办法在网上找到,但我没能拿到截图是视网膜。创建视网膜屏幕截图编程导致非视网膜图像
我了解以下私有API:
UIGetScreenImage();
不能作为苹果将拒绝您的应用程序。但是,这种方法正是我所需要的(640x960屏幕截图)。
我试图在我的iPhone 4以及对视网膜硬件的iPhone 4仿真这种方法,但由此产生的图像分辨率320x480始终。
-(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;
}
我也曾尝试苹果推荐的方法:
- (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;
}
但它也返回一个非视网膜图像: 2012年12月23日19:57:45.205明信片[3351:707]尺寸:{320} 480
有什么明显的我失踪?怎么会有方法,假设采取视网膜屏幕截图返回我非视网膜屏幕截图? 在此先感谢!
除了'image.size'之外,您是否尝试过记录'image.scale'?是1还是2?如果是2,那实际上是一个视网膜图像。 – Pang
哇!我没有意识到图像可以有单独的尺寸和比例设置为2,我检查了返回图像上的比例尺,它是2.0,那么这是否意味着这个图像实际上是640x960?我可以像使用视网膜图像一样使用此图像吗? – bxscikai