Winform下WebBrowser 编辑模式 监听键盘按键事件

最近使用 WebBrowser 做了个富文本编辑器（其实网上有很多很多）。例如下面这个玩意（不要在意界面神马的）

WebBrowser在编辑模式下可以有一些HTML标签的功能，改变字体大小颜色等等等。。

开启编辑模式->

webBrowser1.Url = new Uri("", UriKind.Relative);//这行保证Document不为null

 if (webBrowser1.Document != null)
            {
                var doc = this.webBrowser1.Document.DomDocument as mshtml.IHTMLDocument2;
                if (doc != null)
                {
                    doc.designMode = "on";
                }
            }

各种命令如下->

        webBrowser.Document.ExecCommand([string],[bool],[object]);//编辑模式下使用

        private const string HTML_COMMAND_BOLD = "Bold";                       //加粗
        private const string HTML_COMMAND_UNDERLINE = "Underline";             //下划线
        private const string HTML_COMMAND_ITALIC = "Italic";                   //斜体
        private const string HTML_COMMAND_SUBSCRIPT = "Subscript";             //下标
        private const string HTML_COMMAND_SUPERSCRIPT = "Superscript";         //上标
        private const string HTML_COMMAND_STRIKE_THROUGH = "StrikeThrough";    //删除线
        private const string HTML_COMMAND_FONT_NAME = "FontName";              //字体
        private const string HTML_COMMAND_FONT_SIZE = "FontSize";              //字号
        private const string HTML_COMMAND_FORE_COLOR = "ForeColor";            //字体前景色
        private const string HTML_COMMAND_BACK_COLOR = "BackColor";            //字体背景色
        private const string HTML_COMMAND_INSERT_FORMAT_BLOCK = "FormatBlock"; //加粗
        private const string HTML_COMMAND_REMOVE_FORMAT = "RemoveFormat";      //清楚样式
        private const string HTML_COMMAND_JUSTIFY_LEFT = "JustifyLeft";        //文本左对齐
        private const string HTML_COMMAND_JUSTIFY_CENTER = "JustifyCenter";    //文本中间对齐
        private const string HTML_COMMAND_JUSTIFY_RIGHT = "JustifyRight";      //文本右对齐
        private const string HTML_COMMAND_JUSTIFY_FULL = "JustifyFull";        //文本两端对齐
        private const string HTML_COMMAND_INDENT = "Indent";                   //增大缩进量
        private const string HTML_COMMAND_OUTDENT = "Outdent";                 //减小缩进量
        private const string HTML_COMMAND_INSERT_LINE = "InsertHorizontalRule";//插入分割符
        private const string HTML_COMMAND_INSERT_LIST = "Insert{0}List"; // replace with (Un)Ordered 插入项目符号或项目编号
        private const string HTML_COMMAND_INSERT_IMAGE = "InsertImage";         //插入图像
        private const string HTML_COMMAND_INSERT_LINK = "CreateLink";           //插入链接
        private const string HTML_COMMAND_REMOVE_LINK = "Unlink";               //移除链接
        private const string HTML_COMMAND_TEXT_CUT = "Cut";                     //剪切
        private const string HTML_COMMAND_TEXT_COPY = "Copy";                   //复制
        private const string HTML_COMMAND_TEXT_PASTE = "Paste";                 //粘贴
        private const string HTML_COMMAND_TEXT_DELETE = "Delete";               //删除
        private const string HTML_COMMAND_TEXT_UNDO = "Undo";                   //撤销
        private const string HTML_COMMAND_TEXT_REDO = "Redo";                   //恢复
        private const string HTML_COMMAND_TEXT_SELECT_ALL = "SelectAll";        //全选
        private const string HTML_COMMAND_TEXT_UNSELECT = "Unselect";           //取消选择
        private const string HTML_COMMAND_TEXT_PRINT = "Print";                 // 打印
        private const string HTML_COMMAND_EDITMODE = "EditMode";                // 编辑模式
        private const string HTML_COMMAND_BROWSEMODE = "BrowseMode";            // 浏览模式
        private const string HTML_COMMAND_OVERWRITE = "OverWrite";             //转换插入、覆写模式

下面问题来了，当我编写好东西后，习惯的按了Ctrl+S来进行保存，发现我应该做一个快捷键来保存，但是当添加WebBrowser的KeyUp的事件会报错：

被告知WebBrowser是ActiveX控件不能添加此类事件。所以只有在mshtml中找找关于事件方面的东西

在mshtml中有mshtml.HTMLDocumentClass或者直接使用 mshtml.HTMLDocumentEvents2_Event进行Dom的事件监听:

            mshtml.HTMLDocumentClass documentClass = webBrowser1.Document.DomDocument as mshtml.HTMLDocumentClass;
            documentClass.HTMLDocumentEvents2_Event_onkeyup += new mshtml.HTMLDocumentEvents2_onkeyupEventHandler(documentClass_HTMLDocumentEvents2_Event_onkeyup);
            documentClass.HTMLDocumentEvents_Event_onkeyup += new mshtml.HTMLDocumentEvents_onkeyupEventHandler(documentClass_HTMLDocumentEvents_Event_onkeyup);

            HTMLDocumentEvents2_Event docEvents = webBrowser1.Document.DomDocument as HTMLDocumentEvents2_Event;
            docEvents.onkeyup += new HTMLDocumentEvents2_onkeyupEventHandler(docEvents_onkeyup);
            docEvents.onkeydown += new HTMLDocumentEvents2_onkeydownEventHandler(docEvents_onkeydown);
            docEvents.onkeypress += new HTMLDocumentEvents2_onkeypressEventHandler(docEvents_onkeypress);

但是添加事件后问题又来了，WebBrowser虽然处于编辑模式，却无法写入任何东西。猜测是在事件添加之前WebBrowser没有任何内容的话，添加事件后就会阻挡所有的按键传递。

找到一个折中的办法，在添加事件之前往WebBrowser中写入一个空格:

var docEdit = webBrowser1.Document.DomDocument as IHTMLDocument2;
            if (docEdit != null)
            {
                docEdit.write(" ");
                docEdit.close();
            }

            mshtml.HTMLDocumentClass documentClass = webBrowser1.Document.DomDocument as mshtml.HTMLDocumentClass;
            documentClass.HTMLDocumentEvents2_Event_onkeyup += new mshtml.HTMLDocumentEvents2_onkeyupEventHandler(documentClass_HTMLDocumentEvents2_Event_onkeyup);
            documentClass.HTMLDocumentEvents_Event_onkeyup += new mshtml.HTMLDocumentEvents_onkeyupEventHandler(documentClass_HTMLDocumentEvents_Event_onkeyup);

            HTMLDocumentEvents2_Event docEvents = webBrowser1.Document.DomDocument as HTMLDocumentEvents2_Event; 
            docEvents.onkeyup += new HTMLDocumentEvents2_onkeyupEventHandler(docEvents_onkeyup); 
            docEvents.onkeydown += new HTMLDocumentEvents2_onkeydownEventHandler(docEvents_onkeydown); 
            docEvents.onkeypress += new HTMLDocumentEvents2_onkeypressEventHandler(docEvents_onkeypress);

这个时候就可以进行键盘的按键监听了：