C# 获取网页验证码

转载请注明来源：https://www.cnblogs.com/hookjc/

以下方法必需在WebBrowser控件加载网页完成后才可以调用，否则会提示无法将对象引用到实例，切记！！！ 

public static Image GetRegCodePic(WebBrowser wbMail, string ImgName, string Src, string Alt)
        {
             HTMLDocument doc = (HTMLDocument)wbMail.Document.DomDocument;//

             HTMLBody body = (HTMLBody)doc.body;
             IHTMLControlRange rang = (IHTMLControlRange)body.createControlRange();
             IHTMLControlElement Img;
            if (ImgName == "") //如果没有图片的名字,通过Src或Alt中的关键字来取
            {
                int ImgNum = GetPicIndex(wbMail, Src,Alt);
                if (ImgNum == -1) return null;
                 Img = (IHTMLControlElement)wbMail.Document.Images[ImgNum].DomElement;
             }
            else
                 Img = (IHTMLControlElement)wbMail.Document.All[ImgName].DomElement;

             rang.add(Img);
             rang.execCommand("Copy", false, null);
             Image RegImg = Clipboard.GetImage();
             Clipboard.Clear();
            return RegImg;
         }

        public static int GetPicIndex(WebBrowser wbMail, string Src, string Alt)
        {
            int imgnum = -1;
            for (int i = 0; i < wbMail.Document.Images.Count; i++)　//获取所有的Image元素
            {
                 IHTMLImgElement img = (IHTMLImgElement)wbMail.Document.Images[i].DomElement;
                if (Alt == "")
                {
                    if (img.src.Contains(Src)) return i;
                 }
                else
                {
                    if (!string.IsNullOrEmpty(img.alt))
                    {
                        if (img.alt.Contains(Alt)) return i;
                     }
                 }
             }
            return imgnum;
         }

来源：python脚本自动迁移