iOS【webView 加载微信文章注入JS实现交互 浏览图片及保存】

最近项目某个模块中要求可以实现对网页中图片的查看，并要求在多张图片的情况下可以实现滑动浏览。
所以，问题的集中点就是如何获取所有的图片地址及添加图片的点击事件。不多说，直接上码！

在网页加载完成时，通过js获取图片和添加点击的识别方式

- (void)webViewDidFinishLoad:(UIWebView *)webView {    [IDProgressHUD IDPlaceViewHideDirect:self.view];    //这里是js，主要目的实现对url的获取    static  NSString * const jsGetImages =    @"function getImages(){\    var objs = document.getElementsByTagName(\"img\");\    var imgScr = '';\    for(var i=0;i<objs.length;i++){\    imgScr = imgScr + objs[i].src + '+';\    };\    return imgScr;\    };";    [webView stringByEvaluatingJavaScriptFromString:jsGetImages];//注入js方法    NSString *urlResurlt = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"];    mUrlArray = [NSMutableArray arrayWithArray:[urlResurlt componentsSeparatedByString:@"+"]];    if (mUrlArray.count >= 2) {        [mUrlArray removeLastObject];    }    //urlResurlt 就是获取到得所有图片的url的拼接；mUrlArray就是所有Url的数组    //添加图片可点击js    [mWebView stringByEvaluatingJavaScriptFromString:@"function registerImageClickAction(){\     var imgs=document.getElementsByTagName('img');\     var length=imgs.length;\     for(var i=0;i<length;i++){\     img=imgs[i];\     img.onclick=function(){\     window.location.href='image-preview:'+this.src}\     }\     }"];    [mWebView stringByEvaluatingJavaScriptFromString:@"registerImageClickAction();"];}

//在这个方法中捕获到图片的点击事件和被点击图片的url

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {    //预览图片    if ([request.URL.scheme isEqualToString:@"image-preview"]) {        NSString* path = [request.URL.absoluteString substringFromIndex:[@"image-preview:" length]];        path = [path stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];        //path 就是被点击图片的url        return NO;    }    return YES;}

以下是保存所在作用域的图片

    //添加长按事件    UILongPressGestureRecognizer *longPressed = [[UILongPressGestureRecognizer alloc]                                                 initWithTarget:self action:@selector(longPressed:)];    longPressed.minimumPressDuration = 0.3;    longPressed.delegate = self;    [webView addGestureRecognizer:longPressed];    /** 获取长按事件所在的位置图片 */- (void)longPressed:(UILongPressGestureRecognizer*)recognizer{    if (recognizer.state != UIGestureRecognizerStateBegan) {        return;    }    CGPoint touchPoint = [recognizer locationInView:_webView];    NSString *imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src",                        touchPoint.x, touchPoint.y];    NSString *webImage = [_webView stringByEvaluatingJavaScriptFromString:imgURL];    if([webImage rangeOfString:@"player"].location !=NSNotFound || webImage.length == 0){        return;    }    [self showImageOptionsWithUrl:webImage];}- (void)showImageOptionsWithUrl:(NSString *)imageUrl{    _webImageURL = imageUrl;    IBActionSheet *standardIBAS = [[IBActionSheet alloc] initWithTitle:nil delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:@"保存图片" otherButtonTitles:nil];    [standardIBAS setFont:FontWithSize(SIZE_FONT_CONTENT)];    [standardIBAS setTitleFont:FontWithSize(SIZE_FONT_SUBCONTENT)];    [standardIBAS setButtonTextColor:[UIColor blackColor]];    [standardIBAS showInView:self.navigationController.view];}#pragma mark - IBActionSheetDelegate-(void)actionSheet:(IBActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{    if (buttonIndex == 0) {        NSURL *url = [NSURL URLWithString:_webImageURL];        NSURLSessionConfiguration * configuration = [NSURLSessionConfiguration defaultSessionConfiguration];        NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:[NSOperationQueue new]];        NSURLRequest *imgRequest = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:30.0];        NSURLSessionDownloadTask  *task = [session downloadTaskWithRequest:imgRequest completionHandler:^(NSURL * _Nullable location, NSURLResponse * _Nullable response, NSError * _Nullable error) {            if (error) {                return ;            }            NSData * imageData = [NSData dataWithContentsOfURL:location];            dispatch_async(dispatch_get_main_queue(), ^{                UIImage * image = [UIImage imageWithData:imageData];                UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);            });           }];        [task resume];    }}

后记：js挺好玩，我相信以后还会去多接触它。