ios - 截长图显示不出来

问题描述

问 题

最近要做‘截长图分享’，需要将view上显示的所有内容转换成image。查找资料做了，但是获取的图片只显示一部分，下面是代码，大神给看看：

-（UIImage*)getLongShotsImageView:(UIScrollView*)scrollview

{
        NSMutableArray *imgArray = [[[NSMutableArray alloc]initWithCapacity:0] autorelease];
        
        NSInteger total = ceilf(scrollview.contentSize.height/scrollview.frame.size.height);
        
        CGSize size = CGSizeZero;
        for (NSInteger i = 0; i < total; ++i)
        {
            [scrollview setContentOffset:CGPointMake(0, i*scrollview.frame.size.height)]
            ;
        if (i == total-1) {
            size = CGSizeMake(self.view.frame.size.width, scrollview.contentSize.height- i*scrollview.frame.size.height);
            
        } else {
            size = scrollview.frame.size;
        }
        
        UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);
        CGContextRef context = UIGraphicsGetCurrentContext();
        
        CGContextSaveGState(context);
        CGContextTranslateCTM(context, -scrollview.frame.origin.x, -scrollview.frame.origin.y);
        
        [scrollview.layer renderInContext:context];
        
        CGContextRestoreGState(context);
        
        UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
        [imgArray addObject:img];
        
        UIGraphicsEndImageContext();
    }
    
    // 拼接
    UIImage *image = imgArray[0];
    if (imgArray.count == 1) {
        return image;
    }
    
    for (NSInteger i = 1; i < imgArray.count; i++)
    {
        image = [self combineWithTopImage:image BottomImage:imgArray[i]  ImageSacle:[UIScreen mainScreen].scale];
        if (i == imgArray.count-1) {
            break;
        }
    }
    
    return image;
}

- (UIImage *)combineWithTopImage:(UIImage*)image1 BottomImage:(UIImage*)image2 ImageSacle:(CGFloat)imageSacle
{
 CGFloat w = image1.size.width;
    CGFloat h = image1.size.height + image2.size.height;
    
    CGSize offSize = CGSizeMake(w, h);
    
    UIGraphicsBeginImageContextWithOptions(offSize, NO, imageSacle);
    
    CGRect rect1 = CGRectMake(0, 0, w, image1.size.height);
    
    
    [image1 drawInRect:rect1];

    
    CGRect rect2 = CGRectMake(0, rect1.origin.y+image1.size.height, w, image2.size.height);
    [image2 drawInRect:rect2];
    
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return img;

}

图：

解决方案

你把

 CGContextTranslateCTM(context, -scrollview.frame.origin.x, -scrollview.frame.origin.y);

改成

CGContextTranslateCTM(context, -scrollview.contentOffset.x, -scrollview.contentOffset.y);

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