问题

在WKWebView上的图片，长按会触发系统控件进行保存和共享，但通过系统共享是没法分享图片，只能进行长按手势覆盖，然后用本地控件实现

解决方案

1. 屏蔽WebKit的长按逻辑

 //禁止长按逻辑
    NSMutableString *javascript = [NSMutableString string];
    [javascript appendString:@"document.documentElement.style.webkitTouchCallout='none';"];//禁止长按
    WKUserScript *noneSelectScript = [[WKUserScript alloc] initWithSource:javascript injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
    [config.userContentController addUserScript:noneSelectScript];

2. 添加长按手势

-(void)addLongPressGesture
{
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(startLongPress:)];
    longPress.delegate = self;

    longPress.minimumPressDuration = 0.4f;
    longPress.numberOfTouchesRequired = 1;
    longPress.cancelsTouchesInView = YES;
    [self.locationWebView addGestureRecognizer:longPress];
    
}
- (void)startLongPress:(UILongPressGestureRecognizer *)pressSender
{
    if(pressSender.state == UIGestureRecognizerStateBegan){

       //实现相关功能
        [self detectInWebView:pressSender];
        DebugLog(@"1. 开始长按手势");

    }else if(pressSender.state == UIGestureRecognizerStateEnded){

        //可以添加你长按手势执行的方法,不过是在手指松开后执行
        DebugLog(@"2. 结束长按手势");

    }else if(pressSender.state == UIGestureRecognizerStateChanged){

        //在手指点下去一直不松开的状态执行
        DebugLog(@"3. 长按手势改变");
    }
}

3. 手势中捕捉图片进行处理

- (void)detectInWebView:(UIGestureRecognizer *)ges{

    CGPoint touchPoint = [ges locationInView:ges.view];
    NSString *jsString = [NSString stringWithFormat:@"function getURLandRect(){\
                              var ele=document.elementFromPoint(%f, %f);\
                              var url=ele.src;\
                              var jsonString= `{\"url\":\"${url}\"}`;\
                              return(jsonString)} getURLandRect()", touchPoint.x, touchPoint.y];
    [self.locationWebView evaluateJavaScript:jsString completionHandler:^(id _Nullable result, NSError * _Nullable error) {
        NSData *data = [result dataUsingEncoding:NSUTF8StringEncoding];
        NSDictionary*resultDic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
        NSString* imageURL = resultDic[@"url"];
        if(imageURL.length==0|| [imageURL isEqualToString:@"undefined"]) {
            return;
        }
        NSData* imageData=nil;
        if(([imageURL hasPrefix:@"http"])) {
            imageData = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:imageURL]] returningResponse:NULL error:NULL];
            
        }else{
            NSString*dataString = [[imageURL componentsSeparatedByString:@","]lastObject];
//            imageData = [dataString dataUsingEncoding:NSUTF8StringEncoding];
            imageData = [[NSData alloc] initWithBase64EncodedString:dataString options:NSDataBase64DecodingIgnoreUnknownCharacters];
            
        }
        UIImage*image=[UIImage imageWithData:imageData];
        if(image) {
            //弹框处理
            [self.webModel popoverImageAlertWithImage:image Controller:self];
        }
    }];
}