Color
Dialog
A ColorDialog
control is used to select a color from available colors and also define custom
colors. A typical Color Dialog looks like Figure 1 where you can see there is a
list of basic solid colors and there is an option to create custom colors.
Figure 1
Creating a ColorDialog
We can create a ColorDialog control using a Forms designer
at design-time or using the ColorDialog class in code at run-time (also known as
dynamically). Unlike other Windows Forms controls, a ColorDialog does not have
and not need visual properties like others. The only purpose of ColorDialog to
display available colors, create custom colors and select a color from these
colors. Once a color is selected, we need that color in our code so we can apply
it on other controls.
Again, you can create a ColorDialog at design-time but It
is easier to create a ColorDialog at run-time.
Design-time
To create a ColorDialog control at design-time, you simply
drag and drop a ColorDialog control from Toolbox to a Form in Visual Studio.
After you drag and drop a ColorDialog on a Form, the ColorDialog looks like
Figure 2.
Figure 2
Adding a ColorDialog to a Form adds following two lines of
code.
Friend
WithEvents ColorDialog1
As System.Windows.Forms.ColorDialog
Me.ColorDialog1
= New System.Windows.Forms.ColorDialog()
Run-time
Creating
a ColorDialog control at run-time is merely a work of creating an instance of
ColorDialog class, set its properties and add ColorDialog class to the Form
controls.
First
step to create a dynamic ColorDialog is to create an instance of ColorDialog
class. The following code snippet creates a ColorDialog control object.
Dim
colorDlg As New
ColorDialog()
ShowDialog method of ColorDialog displays the ColorDialog. The following code
snippet sets background color, foreground color, Text, Name, and Font properties
of a ColorDialog.
colorDlg.ShowDialog()
Once the ShowDialog method is called, you can pick colors
on the dialog.
Setting ColorDialog
Properties
After you
place a ColorDialog control on a Form, the next step is to set properties.
The easiest
way to set properties is from the Properties Window. You can open Properties
window by pressing F4 or right click on a control and select Properties menu
item. The Properties window looks like Figure 3.
Figure 3
AllowFullOpen
If you
look at Figure 1, you will see a button called Define Custom Colors on the
ColorDialog. Clicking on this button opens the custom color editor area where
you can define colors by setting RGB color values (between 0 to 255) and can
also select a color from the color area as you can see in Figure 4.
Figure 4
AllowFullOpen property makes sure that Define Custom Color option is
enabled on a ColorDialog. If you wish to disable this option, you can set
AllowFullOpen property to false and your ColorDialog will look like Figure
5.
Figure 5
The
following code snippet sets the AllowFullOpen property to false.
colorDlg.AllowFullOpen =
False
Color,
AnyColor, and SolidColorOnly
Color property
is used to get and set the color selected by the user in a ColorDialog.
AnyColor is
used to get and set whether a ColorDialog displays all available colors in the
set of basic colors.
SolidColorOnly
is used to get and set whether a ColorDialog restricts users to selecting solid
colors only.
The following
code snippet sets these properties.
colorDlg.Color =
Color.Red
colorDlg.SolidColorOnly =
False
Using ColorDialog in
Applications
Now let's
create an application that will use a ColorDialog to set colors of bunch of
controls. The Windows Forms application looks like Figure 6.
Figure 6
In Figure 6,
we have a few Windows Forms controls and clicking on Foreground Color and
Background Color buttons will let user select a color and set that color
as foreground and background colors of the controls. After selecting foreground
and background colors, the Form looks like Figure 7.
Figure 7
The following
code snippet is the code for Foreground Color and Background Color buttons click
event handlers.
Public
Class Form1
Private
Sub ForegroundButton_Click(ByVal
sender As System.Object,
ByVal e As
System.EventArgs)
Handles ForegroundButton.Click
Dim
colorDlg As New
ColorDialog()
colorDlg.AllowFullOpen =
False
colorDlg.ShowHelp =
True
colorDlg.Color =
Color.Red
colorDlg.SolidColorOnly =
False
If (colorDlg.ShowDialog()
= Windows.Forms.DialogResult.OK)
Then
TextBox1.ForeColor =
colorDlg.Color
ListBox1.ForeColor =
colorDlg.Color
Button3.ForeColor =
colorDlg.Color
End
If
End
Sub
Private
Sub BackgroundButton_Click(ByVal
sender As System.Object,
ByVal e As
System.EventArgs)
Handles BackgroundButton.Click
Dim
colorDlg As New
ColorDialog()
If (colorDlg.ShowDialog()
= Windows.Forms.DialogResult.OK)
Then
TextBox1.BackColor =
colorDlg.Color
ListBox1.BackColor =
colorDlg.Color
Button3.BackColor =
colorDlg.Color
End
If
End
Sub
Private
Sub AddButton_Click(ByVal
sender As System.Object,
ByVal e As
System.EventArgs)
Handles AddButton.Click
ListBox1.Items.Add(TextBox1.Text)
End
Sub
End
Class
Summary
A
ColorDialog control allows users to launch Windows Color Dialog and let them
select a solid color or create a custom color from available colors. In this
article, we discussed how to use a Windows Color Dialog and set its properties
in a Windows Forms application.