Question

例如，png文件是1200（h）x 50（w）像素，我怎样才能切割 png并加载6 UIImage s，每个200（h） x 50（w）。谢谢！

编辑 - 感谢Michal的回答，最终代码：

 CGImageRef imageToSplit = [UIImage imageNamed:@"huge.png"].CGImage;
 CGImageRef partOfImageAsCG = CGImageCreateWithImageInRect(imageToSplit, CGRectMake(0, 0, 50, 50));

 UIImage *partOfImage = [UIImage imageWithCGImage:partOfImageAsCG]; 
 // ...

 CGImageRelease(partOfImageAsCG);

Answer 1

查看CGImageCreateWithImageInRect函数。它适用于CGImage，但很容易在那个和UIImage之间进行转换。

这是一个例子（从内存中输入，可能无法编译）：

CGImageRef imageToSplit = [UIImage imageNamed:@"huge.png"].CGImage;
CGImageRef partOfImageAsCG = CGImageCreateWithImageInRect(imageToSplit, CGRectMake(0, 0, 200, 50));
CGRelease(imageToSplit);
UIImage *partOfImage = [UIImage imageWithCGImage:partOfImageAsCG];
CGImageRelease(partOfImageAsCG);

Answer 2

可重复使用的方法：

-(UIImage*)ExtractImageOn:(CGPoint)pointExtractedImg ofSize:(CGSize)sizeExtractedImg FromSpriteSheet:(UIImage*)imgSpriteSheet
{
    UIImage *ExtractedImage;

    CGRect rectExtractedImage;

    rectExtractedImage=CGRectMake(pointExtractedImg.x,pointExtractedImg.y,sizeExtractedImg.width,sizeExtractedImg.height);

    CGImageRef imgRefSpriteSheet=imgSpriteSheet.CGImage;

    CGImageRef imgRefExtracted=CGImageCreateWithImageInRect(imgRefSpriteSheet,rectExtractedImage);

    ExtractedImage=[UIImage imageWithCGImage:imgRefExtracted];

    CGImageRelease(imgRefExtracted);

    //CGImageRelease(imgRefSpriteSheet); I have commented it because
    // we should not release the object that we don't own.
    // So why do we release imgRefExtracted alone? because it has 
    // name create in its method so the ownership comes to us so we
    // have to release it.

    return ExtractedImage;

}

供参考：

即使已经清楚地回答了我的想法，我认为将它作为简单的可重复使用的“复制粘贴”代码片段对程序员来说会有很多帮助，我将答案归结为michal

如何将大型精灵png切割成较小的UIImages？

2 个答案: