ios 图片拼接 图片缩放 将webView上面的内容转化为图片 归纳整理

//将image1拼接到image2上

- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2

{

@autoreleasepool {

CGSize size;

if (image1.size.width > image2.size.width)
{

size = CGSizeMake(image1.size.width, image1.size.height+image2.size.height);

} else {

size = CGSizeMake(image2.size.width, image1.size.height+image2.size.height);

}

UIGraphicsBeginImageContext(size);

// Draw image1

[image1 drawInRect:CGRectMake(image1.size.width > image2.size.width?0:(image2.size.width-image1.size.width)/2,
image2.size.height, image1.size.width, image1.size.height)];

// Draw image2

[image2 drawInRect:CGRectMake(image1.size.width > image2.size.width?(image1.size.width-image2.size.width)/2:0, 0,
image2.size.width, image2.size.height)];

UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return resultingImage;

}

}

//图片缩放

- (UIImage *)convertImage:(UIImage *)origImage scope:(CGFloat)scope

{

UIImage *image = nil;

CGSize size = origImage.size;

if (size.width <= scope && size.height <= scope) {

// do nothing

image = origImage;

} else {

CGFloat length = size.width;

if (size.width < size.height) {

length = size.width;

}

CGFloat f = scope/length;

CGSize newSize = CGSizeMake(size.width*f, size.height*f);

//

UIGraphicsBeginImageContext(newSize);

// Tell the old image to draw in this new context, with the desired

// new size

[origImage drawInRect:CGRectMake(0, 0, newSize.width,
newSize.height)];

// Get the new image from the context

image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

}

return image;

}

//将webView上面的内容转化为图片

- (UIImage *)webContentImage{

CGSize boundsSize = web.bounds.size;

CGFloat boundsWidth = web.bounds.size.width;

CGFloat boundsHeight = web.bounds.size.height;

CGPoint offset = web.scrollView.contentOffset;

[web.scrollView setContentOffset:CGPointMake(0, 0)];

CGFloat contentHeight = web.scrollView.contentSize.height;

NSMutableArray *images = [NSMutableArray array];

while (contentHeight > 0) {

UIGraphicsBeginImageContext(boundsSize);

[web.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

[images addObject:image];

CGFloat offsetY = web.scrollView.contentOffset.y;

[web.scrollView setContentOffset:CGPointMake(0, offsetY + boundsHeight)];

contentHeight -= boundsHeight;

}

[web.scrollView setContentOffset:offset];

UIGraphicsBeginImageContext(web.scrollView.contentSize);

[images enumerateObjectsUsingBlock:^(UIImage *image, NSUInteger idx, BOOL *stop) {

[image drawInRect:CGRectMake(0, boundsHeight * idx, boundsWidth, boundsHeight)];

}];

UIImage *fullImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return fullImage;

}