Rich Text Boxes

Want a full-fledged word processor in your application? Use a rich text box. Not only can you enter formatted text (selecting fonts, italics, bolding, and more) in a rich text box, you also can save that text in rich text format (RTF) files, and read RTF files in it. Commercial word processors like Microsoft Word can read RTF files, allowing you to interface to those word processors fully. (In fact, many people prefer RTF files these days because they cannot harbor macro viruses.)

We've discussed rich text boxes in the In Depth section of this chapter. Take a look at Tables 5.8, 5.9, and 5.10 to see the notable properties, methods, and events of the RichTextBox class. These tables do not include all the notable properties, methods, and events this class inherits from the Control class—you'll find them in Tables 5.1, 5.2, and 5.3.

Table 5.8: Noteworthy public properties of *RichTextBox* objects.
Property	Means
AutoSize	Sets/gets a value specifying if the size of the rich text box automatically adjusts when the font changes.
AutoWordSelection	Sets/gets a value specifying if automatic word selection is enabled.
BorderStyle	Sets/gets the border type of the rich text box.
BulletIndent	Sets/gets the indentation used in the rich text box when the bullet style is applied to the text.
CanRedo	Indicates if there were actions in rich text box that can be reapplied.
CanUndo	Returns a value specifying if the user can undo the previous operation in the rich text box.
DetectUrls	Sets/gets a value specifying if the rich text box should detect URLs when typed into the RichTextBox control.
HideSelection	Sets/gets a value specifying if the selected text should stay highlighted when the RichTextBox control loses focus.
Lines	Sets/gets the lines of text in a RichTextBox control.
MaxLength	Sets/gets the maximum number of characters the user can type into the rich text box.
Modified	Sets/gets a value that indicates that the RichTextBox control has been modified by the user since the Control was created or its contents were last set.
Multiline	Sets/gets a value specifying if this is a multiline RichTextBox control.
PreferredHeight	Gets the preferred height for a single-line rich text box.
ReadOnly	Sets/gets a value specifying if text in the rich text box is read-only.
RightMargin	Sets/gets the size of a single line of text within the RichTextBox control.
Rtf	Sets/gets the text of the RichTextBox control, including all rich text format (RTF) codes.
ScrollBars	Sets/gets the kind of scroll bars to display in the RichTextBox control.
SelectedRtf	Sets/gets the currently selected rich text format (RTF) formatted text in the control.
SelectedText	Sets/gets the selected text within the rich text box.
SelectionAlignment	Sets/gets the alignment to apply to the current selection or insertion point.
SelectionBullet	Sets/gets a value specifying if the bullet style is applied to the current selection or insertion point.
SelectionCharOffset	Sets/gets if text in the RichTextBox control appears on the baseline, as a superscript, or as a subscript.
SelectionColor	Sets/gets the text color of the current text selection or insertion point.
SelectionFont	Sets/gets the font of the current text selection or insertion point.
SelectionHangingIndent	Sets/gets the distance between the left edge of the first line of text in the selected paragraph and the left edge of the next lines in the same paragraph.
SelectionIndent	Sets/gets the distance in pixels between the left edge of the rich text box and the left edge of the current text selection or text added after the insertion point.
SelectionLength	Sets/gets the number of characters selected in control.
SelectionRightIndent	The distance in pixels between the right edge of the RichTextBox control and the right edge of the text that is selected.
SelectionStart	Sets/gets the starting point of text selected in the text box.
SelectionTabs	Sets/gets the absolute tab stop positions in a RichTextBox control.
Text	Sets/gets the current text in the rich text box.
TextLength	Gets the length of text in the RichTextBox control.
WordWrap	Indicates if a multiline RichTextBox control automatically wraps words.
ZoomFactor	Sets/gets the current zoom level of the rich text box.

Table 5.9: Noteworthy public methods of *RichTextBox* objects.
Method	Means
AppendText	Appends text to the current text of the rich text box.
CanPaste	Determines if you can paste information from the Clipboard.
Clear	Clears all text from the RichTextBox control.
ClearUndo	Clears information about the most recent operation from the undo buffer of the rich text box.
Copy	Copies the current selection in the rich text box to the Clipboard.
Cut	Moves the current selection in the rich text box to the Clipboard.
Find	Searches for text within the contents of the rich text box.
GetLineFromCharIndex	Gets the line number from the specified character position within the text of the RichTextBox control.
GetPositionFromCharIndex	Gets the location within the control at the specified character index.
LoadFile	Loads the contents of a file into the RichTextBox control.
Paste	Pastes the contents of the Clipboard into the RichTextBox control.
Redo	Reapplies the last operation that was undone in the RichTextBox control.
SaveFile	Saves the contents of the rich text box to a file.
ScrollToCaret	Scrolls the contents of the RichTextBox control to the current caret position.
Select	Selects text within the RichTextBox control.
SelectAll	Selects all text in the rich text box.
Undo	Undoes the last edit operation in the rich text box.

Table 5.10: Noteworthy public events of *RichTextBox* objects.
Event	Means
Click	Occurs when the rich text box is clicked.
LinkClicked	Occurs when the user clicks on a link within the text of the RichTextBox control.
ModifiedChanged	Occurs when the value of the Modified property is changed.
ReadOnlyChanged	Occurs when the value of the ReadOnly property is changed.
SelectionChanged	Occurs when the selection of text within the RichTextBox control is changed.
VScroll	Occurs when the user clicks the vertical scroll bars of the RichTextBox control.

Tip

Now you can even use a RichTextBox for Web-style links by setting the DetectUrls property to True and writing code to handle the LinkClicked event.