iOS-按大小拍摄UIScrollView可见区域的屏幕截图

我发现了这个，答案是完美的。但是如果我想自己定尺寸呢？如何为此更改

滚动视图.contentOffset

例如，我想这样称呼它：

#define multiplier 3.0f

CGSize size = CGSizeMake(scrollView.frame.size.width*multiplier, scrollView.frame.size.height*multiplier); 
UIImage *backgroungImage = [self renderScrollViewToImageWith:scrollView size:size];

-(UIImage *)renderScrollViewToImageWith:(UIScrollView *)_scrollView size:(CGSize)size
{
    UIScrollView *contentScrollView = _scrollView;

    UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);

    //what do I do here???
    CGPoint offset = contentScrollView.contentOffset;
    CGContextTranslateCTM(UIGraphicsGetCurrentContext(), -offset.x, -offset.y); <-- what do I do here?

    [contentScrollView drawViewHierarchyInRect:CGRectMake(0, 0, size.width, size.height) afterScreenUpdates:YES];
    UIImage *visibleScrollViewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return visibleScrollViewImage;
}

#定义乘数3.0f
CGSize size=CGSizeMake（scrollView.frame.size.width*乘数，scrollView.frame.size.height*乘数）；
UIImage*BackgroundingImage=[自渲染CrollViewToImageWith:scrollView大小：大小]；
-（UIImage*）renderScrollViewToImageWith:（UIScrollView*）\u scrollView大小：（CGSize）大小
{
UIScrollView*contentScrollView=\u scrollView；
UIGraphicsBeginImageContextWithOptions（大小，否，[UIScreen Main Screen].scale）；
//我在这里做什么？？？
CGPoint offset=contentScrollView.contentOffset；
CgContextTranslateCm（UIGraphicsGetCurrentContext（），-offset.x，-offset.y）；试试这个

CGRect croppingRect = viewToTakeScreenShot.bounds;

UIGraphicsBeginImageContextWithOptions(croppingRect.size, NO, [UIScreen mainScreen].scale);
CGContextRef context = UIGraphicsGetCurrentContext();
if (context == NULL) return nil;
CGContextTranslateCTM(context, -croppingRect.origin.x, -croppingRect.origin.y);

[viewToTakeScreenShot layoutIfNeeded];
[viewToTakeScreenShot.layer renderInContext:context];

UIImage *screenshotImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

试试这个，它会对你有帮助的