我正在尝试以编程方式进行视网膜屏幕截图,我已经尝试了在网上找到的每一种方法,但是我无法获得视网膜屏幕截图。
我了解以下私有API:
我了解以下私有API:
UIGetScreenImage();
此方法不能使用,因为苹果将拒绝您的应用。然而,这种方法返回我需要的准确结果(640x960屏幕截图)。
我已经在我的iPhone 4上以及在视网膜硬件的iPhone 4模拟器上尝试了这种方法,但生成的图像始终为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;
}
我也尝试了Apple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: 2012-12-23 19:57:45.205 PostCard[3351:707] 大小:{320, 480}
我是否漏掉了什么明显的东西?为什么那些应该获取视网膜截图的方法会返回非视网膜截图? 提前感谢!
image.size
,你尝试过记录image.scale
吗?它是1还是2?如果是2,那么它实际上是一张Retina图片。 - Pang