|
|
|
| Title | Show and hide TextBox scroll bars as needed in Visual Basic 2005 |
|---|
| Description | This example shows how to show and hide TextBox scroll bars as needed in Visual Basic 2005. |
|---|
| Keywords | TextBox, scroll bar |
|---|
| Categories | Controls |
|---|
|
|
|
Subroutine CheckScrollBars displays or hides a TextBox's vertical scroll bar depending on whether it is big enough to hold its text. The code makes a Graphics object associated with the TextBox. It makes a layout area that fills the TextBox and calls the Graphics object's MeasureString method to see how much of the control's text will fit. If the text won't all fit, the program displays the TextBox's vertical scroll bar.
|
|
' See if the TextBox needs a vertical scroll bar.
Private Sub CheckScrollBars(ByVal txt As TextBox)
' Make a Graphics object for the TextBox.
Dim gr As Graphics
gr = txt.CreateGraphics()
' Make a layout rectangle.
Dim layout_area As New SizeF(txt.ClientSize.Width, _
txt.ClientSize.Height)
Using sf As New StringFormat()
Dim chars_fitted, lines_filled As Integer
gr.MeasureString(txt.Text, txt.Font, layout_area, _
sf, chars_fitted, lines_filled)
' See if all characters fitted.
If chars_fitted < txt.Text.Length Then
txt.ScrollBars = ScrollBars.Vertical
Else
txt.ScrollBars = ScrollBars.None
End If
End Using
End Sub
|
|
|
The example program checks its TextBox whenever its text changes or it is resized.
|
|
Private Sub txtTest_Resize(ByVal sender As Object, ByVal e _
As System.EventArgs) Handles txtTest.Resize
CheckScrollBars(txtTest)
End Sub
Private Sub txtTest_TextChanged(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
txtTest.TextChanged
CheckScrollBars(txtTest)
End Sub
|
| |
|
| |
|
|
