截取滚动视图的长图片（如tableview等）

/**

截取滚动视图的长图片（如tableview等）

@param scroller 滚动视图

@return 截取的长图

*/

+ (UIImage *)captureImageLonge:(UIScrollView*)scroller{

//（1）截取长图

UIImage* image = nil;

UIGraphicsBeginImageContextWithOptions(scroller.contentSize, YES, 0.0);

//保存collectionView当前的偏移量

CGPoint savedContentOffset = scroller.contentOffset;

CGRect saveFrame = scroller.frame;

//将collectionView的偏移量设置为(0,0)

scroller.contentOffset = CGPointZero;

scroller.frame = CGRectMake(0, 0, scroller.contentSize.width, scroller.contentSize.height);

//在当前上下文中渲染出collectionView

[scroller.layer renderInContext: UIGraphicsGetCurrentContext()];

//截取当前上下文生成Image

image = UIGraphicsGetImageFromCurrentImageContext();

//恢复collectionView的偏移量

scroller.contentOffset = savedContentOffset;

scroller.frame = saveFrame;

UIGraphicsEndImageContext();

if (image != nil) {

//（2）保存到本地相册

ALAssetsLibrary * library = [ALAssetsLibrary new];

NSData * data = UIImageJPEGRepresentation(image, 1.0);

[library writeImageDataToSavedPhotosAlbum:data metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {

if(!error){

//顶部状态栏提醒

[JDStatusBarNotification showJDStatusBar:@"截屏成功，已为你保存到相册"];

}else{

//顶部状态栏提醒

[JDStatusBarNotification showJDStatusBar:@"抱歉，截屏失败"];

}

}];

return image;

}else {

return nil;

}

}