这是缩放大小的版本,只需将size.width和size.height替换为任意目标大小的缩放。
为的UIView:
-(UIImage*)convertViewToImage:(UIView*)v withScale:(float)scale{
//create bitmap context with scaled size
CGSize s = v.bounds.size;
s.width *= scale;
s.height *= scale;
UIGraphicsBeginImageContextWithOptions(s, NO, [UIScreen mainScreen].scale);
//scale CTM to render and resotre CTM
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextScaleCTM(context, scale, scale);
[v.layer renderInContext: context];
CGContextRestoreGState(context);
UIImage*image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
为UIScrollView的
-(UIImage*)convertScrollContentToImage:(UIScrollView*)sv withScale:(float)scale{
//create bitmap context with scaled size
CGSize s = sv.contentSize;
s.width *= scale;
s.height *= scale;
UIGraphicsBeginImageContextWithOptions(s, NO, [UIScreen mainScreen].scale);
{
//set scroll.frame.size to contentSize, and contentOffset to 0
CGPoint savedContentOffset = sv.contentOffset;
CGRect savedFrame = sv.frame;
sv.contentOffset = CGPointZero;
sv.frame = CGRectMake(0, 0, sv.contentSize.width, sv.contentSize.height);
//scale CTM to render and resotre CTM
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextScaleCTM(context, scale, scale);
[sv.layer renderInContext: context];
CGContextRestoreGState(context);
//set scroll.frame.size and ContentOffset back
sv.contentOffset = savedContentOffset;
sv.frame = savedFrame;
}
UIImage*image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
为downvote任何意见或只是曳身边?如果我做错了什么,会很好地告知它是什么。 – Vive
我正在寻找一些方法来渲染图层到不同的大小,最后我找到了方法,您的答案可能会误导其他人类似于我。 – lbsweek