HTMLTextBox--基于WebBrowser的HTML编辑控件

 

   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。