这是一个Rich Text Editor模式的编辑控件。正如我们所知，尽管微软已经在.NET Framework中提供了RichTextBox控件用于显示富文本，但在某些实际编辑工作中还是不尽人意。这个控件可以用于真正的编辑工作。界面如下：
HTMLTextBox控件内部构造
HTMLTextBox 是 UserControl 的子类，主要由两部分组成：一个ToolBar和一个WebBrowser 控件。
怎样使WebBrowser可编辑？
执行下面的代码后，WebBrowser将进入"Edit Mode"（编辑模式）。
webBrowserBody.Document.ExecCommand("EditMode", false, null);
怎样加粗字体？
执行下面的代码可使选定字符字体加粗。
webBrowserBody.Document.ExecCommand("Bold", false, null);
此控件中的所有操作都是调用WebBrowser.Document的ExecCommand函数。有关ExecCommand的详细资料，参见Microsoft MSDN。
附注：Microsoft在Command Identifiers中提醒有些命令将不再得到支持，但实际上它们工作得很好，不要100％相信微软。
Command Identifiers
2D-Position
Allows absolutely positioned elements to be moved by dragging.
AbsolutePosition
Sets an element's position property to "absolute."
BackColor
Sets or retrieves the background color of the current selection.
BlockDirLTR
Not currently supported.
BlockDirRTL
Not currently supported.
Bold
Toggles the current selection between bold and nonbold.
BrowseMode
Not currently supported.
ClearAuthenticationCache
Clears all authentication credentials from the cache. Applies only to execCommand.
Copy
Copies the current selection to the clipboard.
CreateBookmark
Creates a bookmark anchor or retrieves the name of a bookmark anchor for the current selection or insertion point.
CreateLink
Inserts a hyperlink on the current selection, or displays a dialog box enabling the user to specify a URL to insert as a hyperlink on the current selection.
Cut
Copies the current selection to the clipboard and then deletes it.
Delete
Deletes the current selection.
DirLTR
Not currently supported.
DirRTL
Not currently supported.
EditMode
Not currently supported.
FontName
Sets or retrieves the font for the current selection.
FontSize
Sets or retrieves the font size for the current selection.
ForeColor
Sets or retrieves the foreground (text) color of the current selection.
FormatBlock
Sets the current block format tag.
Indent
Increases the indent of the selected text by one indentation increment.
InlineDirLTR
Not currently supported.
InlineDirRTL
Not currently supported.
InsertButton
Overwrites a button control on the text selection.
InsertFieldset
Overwrites a box on the text selection.
InsertHorizontalRule
Overwrites a horizontal line on the text selection.
InsertIFrame
Overwrites an inline frame on the text selection.
InsertImage
Overwrites an image on the text selection.
InsertInputButton
Overwrites a button control on the text selection.
InsertInputCheckbox
Overwrites a check box control on the text selection.
InsertInputFileUpload
Overwrites a file upload control on the text selection.
InsertInputHidden
Inserts a hidden control on the text selection.
InsertInputImage
Overwrites an image control on the text selection.
InsertInputPassword
Overwrites a password control on the text selection.
InsertInputRadio
Overwrites a radio control on the text selection.
InsertInputReset
Overwrites a reset control on the text selection.
InsertInputSubmit
Overwrites a submit control on the text selection.
InsertInputText
Overwrites a text control on the text selection.
InsertMarquee
Overwrites an empty marquee on the text selection.
InsertOrderedList
Toggles the text selection between an ordered list and a normal format block.
InsertParagraph
Overwrites a line break on the text selection.
InsertSelectDropdown
Overwrites a drop-down selection control on the text selection.
InsertSelectListbox
Overwrites a list box selection control on the text selection.
InsertTextArea
Overwrites a multiline text input control on the text selection.
InsertUnorderedList
Converts the text selection into an ordered list.
Italic
Toggles the current selection between italic and nonitalic.
JustifyCenter
Centers the format block in which the current selection is located.
JustifyFull
Not currently supported.
JustifyLeft
Left-justifies the format block in which the current selection is located.
JustifyNone
Not currently supported.
JustifyRight
Right-justifies the format block in which the current selection is located.
LiveResize
Causes the MSHTML Editor to update an element's appearance continuously during a resizing or moving operation, rather than updating only at the completion of the move or resize.
MultipleSelection
Allows for the selection of more than one site selectable element at a time when the user holds down the SHIFT or CTRL keys.
Open
Not currently supported.
Outdent
Decreases by one increment the indentation of the format block in which the current selection is located.
OverWrite
Toggles the text-entry mode between insert and overwrite.
Paste
Overwrites the contents of the clipboard on the current selection.
PlayImage
Not currently supported.
Print
Opens the print dialog box so the user can print the current page.
Redo
Not currently supported.
Refresh
Refreshes the current document.
RemoveFormat
Removes the formatting tags from the current selection.
RemoveParaFormat
Not currently supported.
SaveAs
Saves the current Web page to a file.
SelectAll
Selects the entire document.
SizeToControl
Not currently supported.
SizeToControlHeight
Not currently supported.
SizeToControlWidth
Not currently supported.
Stop
Not currently supported.
StopImage
Not currently supported.
StrikeThrough
Not currently supported.
Subscript
Not currently supported.
Superscript
Not currently supported.
UnBookmark
Removes any bookmark from the current selection.
Underline
Toggles the current selection between underlined and not underlined.
Undo
Undo the previous command.
Unlink
Removes any hyperlink from the current selection.
Unselect
Clears the current selection.简介
关于可选字体
此控件中的所有可选字体将利用下面的代码获得。
foreach (FontFamily family in FontFamily.Families)
{
toolStripComboBoxName.Items.Add(family.Name);
}
关于字体大小
在HTML页面中共有7种字体尺寸。下面的表格列出了HTML字体尺寸与常用字体尺寸的对应关系：
HTML 字体尺寸
常用字体尺寸
1
8
2
10
3
12
4
14
5
18
6
24
7
36
为防止混乱，控件使用常用字体尺寸代替HTML字体尺寸。
如何使用HTMLTextBox
作为一个UserControl，HTMLTextBox使用起来非常方便。没有重写或公开太多的属性和方法，只提供了两个公用属性：Text 和 Images。你可以根据需要自由地添加。
Text: 用于获取或设置更有意义的文本，已重写。
·get: 返回整个HTML 内容，包括 和 等。
·set: 设置任何文本值并显示在控件中。同时，“/r/n” 将自动转换为“
”（为了使段落间隔看起来不致于过大—译者注）
Images: 设置所有附加图像的绝对路径
注意: HTMLTextBox将引用COM组件"Microsoft HTML Object Library"。
关于例程
是一个Email发送程序，界面如下：
运行前，MailSender.cs中的第23-26行代码需做适当修改。
string host="192.168.22.12";
int port=25;
string userid="jay.liu";
string password="1111";
讨厌的BUG
插入编辑区的图像无法调整大小，而且也没有异常抛出。目前不知道原因，也还没有解决方案。
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/mane_yao/archive/2010/05/07/5565616.aspx
