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iOS加载WebView上图片获取

iOS加载WebView上图片获取

作者: 一年影绰 | 来源:发表于2017-05-02 11:19 被阅读402次
    定义一个获取图片

    @property(nonatomic,strong)NSMutableArray *imgUrlArray;
    - (NSMutableArray *)imgUrlArray { if (!_imgUrlArray) { _imgUrlArray = [NSMutableArray array]; } return _imgUrlArray; }

    初始化webview 没有头部的添加上头部
        NSString *htmlString = [NSString stringWithFormat:@"内容",_newtitle,_content];
        [_webView loadHTMLString:htmlString baseURL:nil];
    
    附上头部内容格式
    <!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html xmlns=\"http://www.w3.org/1999/xhtml\"><head><meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" /><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=2.0, user-scalable=yes\" /><style type=\"text/css\">img{width:100%%}</style></head><body><br><center><font style=\"text-align:center;font-size:20px;\">%@</font></center><br><hr width=\"100%%\" color=#dbdbdb SIZE=1 /><div style=\"padding-right: 10px;padding-left: 10px\"><font style=\"line-height:1.5;\" >%@</font></div></body></html>
    
    接着就是写webview的代理了
    /**
     *  开始加载webView
     */
    - (void)webViewDidStartLoad:(UIWebView *)webView {
      //@"正在加载"
    }
    
    /**
     *  webView加载完成
     */
    - (void)webViewDidFinishLoad:(UIWebView *)webView {
        // 网页注入JS获取图片资源、添加点击事件
        //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()"];
        [self.imgUrlArray setArray:[urlResurlt componentsSeparatedByString:@"+"]];
        if (self.imgUrlArray.count >= 2) {
            [self.imgUrlArray removeLastObject];
        }
        //图片添加点击js
        [webView 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}\
         }\
         }"];
        [webView stringByEvaluatingJavaScriptFromString:@"registerImageClickAction();"];
    }
    

    处理点击事件 执行跳转界面显示图片 或者其他显示图片事件

    - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
    {
        //预览图片
        if ([request.URL.scheme isEqualToString:@"image-preview"]) {
            //操作
        }
        return YES;
    }
    
     *  webView加载失败
     */
    - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
        
        [SVProgressHUD dismiss];
        [MBProgressHUD showInfoMessage:@"加载失败"];
    }
    

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