如何使用CGImageCreateWithImageInRect for iPhone 4（HD）？ [英] How use CGImageCreateWithImageInRect for iPhone 4 (HD)?

问题描述

我使用以下代码从精灵中获取图像。除了iPhone 4（高清版）外，它在任何地方都能正常工作。

I use the following code to getting images from the sprite. And it works fine everywhere except the iPhone 4 (HD version).

- (UIImage *)croppedImage:(CGRect)rect {
    CGImageRef image = CGImageCreateWithImageInRect([self CGImage], rect);
    UIImage *result = [UIImage imageWithCGImage:image];
    CGImageRelease(image);
    return result;
}

iPhone 4自动加载图像的高清版本（[e-mail] ）而不是sprite.png。原始图像具有比例2，但结果图像具有比例1和错误的大小。

The iPhone 4 automatically load HD version of the image ([e-mail]) instead sprite.png. The original image has a scale 2, but the resulting image has a scale 1 and wrong size.

如何考虑到iPhone 3G的不同比例来处理此行为[ s]和iPhone 4？

How to handle this behavior taking into account the different scales for iPhone 3G[s] and the iPhone 4?

我读过这个文档，但关于使用 CGImageCreateWithImageInRect 这里什么也没说。

I have read this document, but about the use CGImageCreateWithImageInRect here says nothing.

推荐答案

我可以告诉CGImageCreateWithImageInRect会做正确的事情。你需要改变的是UIImage的启动

From what I can tell the CGImageCreateWithImageInRect will do the right thing. What you need to change is the UIImage initilization

http://developer.apple.com/iphone/library/documentation/uikit/reference/UIImage_Class /Reference/Reference.html#//apple_ref/occ/clm/UIImage/imageWithCGImage:scale:orientation ：

将其更改为 [UIImage imageWithCGImage：图像比例：self.scale orientation：self。 imageOrientation] 它应该可以正常工作。 （假设这是UIImage上的类别，它看起来像是）

Change it to [UIImage imageWithCGImage:image scale:self.scale orientation:self. imageOrientation] and it should work just fine. (this is assuming this is a category on UIImage which it looks like it is)

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