.h文件

#import <WebKit/WebKit.h>

 NS_ASSUME_NONNULL_BEGIN

@interface WKWebView (CTMViewCapture)
-(void)CTMContentCaptureCompletionHandler:(void(^)(UIImage*capturedImage))completionHandler;

 -(void)CTMContentCaptureWithoutOffsetCompletionHandler:(void(^)(UIImage *capturedImage))completionHandler;

@end

NS_ASSUME_NONNULL_END

.m文件

#import "WKWebView+CTMViewCapture.h"
@implementation WKWebView (CTMViewCapture)
-(void)CTMContentCaptureCompletionHandler:(void(^)(UIImage
*capturedImage))completionHandler{

CGPoint offset =self.scrollView.contentOffset;
UIView *snapShotView = [self       snapshotViewAfterScreenUpdates:YES];
  snapShotView.frame =CGRectMake(self.frame.origin.x, self.frame.origin.y,snapShotView.frame.size.width, snapShotView.frame.size.height);

  [self.superview addSubview:snapShotView];
     if(self.frame.size.height < self.scrollView.contentSize.height){
    self.scrollView.contentOffset =CGPointMake(0, self.scrollView.contentSize.height - self.frame.size.height);
}
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)),
dispatch_get_main_queue(), ^{ self.scrollView.contentOffset = CGPointZero;
[self CTMContentCaptureWithoutOffsetCompletionHandler:^(UIImage *capturedImage){
self.scrollView.contentOffset = offset;
[snapShotView removeFromSuperview];
completionHandler(capturedImage);}];
});

}
-(void)CTMContentCaptureWithoutOffsetCompletionHandler:(void(^)(UIImage *capturedImage))completionHandler{
UIView *containerView = [[UIView alloc]initWithFrame:self.bounds];

CGRect bakFrame = self.frame;
UIView *bakSuperView = self.superview;
NSInteger bakIndex = [self.superview.subviews indexOfObject:self];

[self removeFromSuperview];
[containerView addSubview:self];

CGSize totalSize = self.scrollView.contentSize;

float page = floorf(totalSize.height/containerView.bounds.size.height);

self.frame = CGRectMake(0, 0, containerView.bounds.size.width, self.scrollView.contentSize.height);
UIGraphicsBeginImageContextWithOptions(totalSize, false, [UIScreen mainScreen].scale);
[self CTMContentPageDrawTargetView:containerView index:0 maxIndex:(int)page drawCallback:^{
    UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    [self removeFromSuperview];
    [bakSuperView insertSubview:self atIndex:bakIndex];
    
    self.frame = bakFrame;
    
    [containerView removeFromSuperview];
    
    completionHandler(capturedImage);
}];

}

- (void)CTMContentPageDrawTargetView:(UIView *)targetView index:(int)index maxIndex:(int)maxIndex drawCallback:(void(^)())drawCallback{
CGRect splitFrame = CGRectMake(0, (float)index * targetView.frame.size.height, targetView.bounds.size.width, targetView.frame.size.height);

CGRect myFrame = self.frame;
myFrame.origin.y = - ((float)index * targetView.frame.size.height);
self.frame = myFrame;

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
    [targetView drawViewHierarchyInRect:splitFrame afterScreenUpdates:YES];
    
    if(index<maxIndex){
        [self CTMContentPageDrawTargetView:targetView index:index + 1 maxIndex:maxIndex drawCallback:drawCallback];
    }else{
        drawCallback();
    }
});
   }