C# – How to use ColorDialog?

ColorDialog is one of the common dialog in .Net Framework; used to display the available colors and also allows us to define custom colors. Through this article we are going to discuss, how we use ColorDialog.

Usually we have Standard colors and User defined colors. By modifying the individual color components of the Standard colors, we can define our own custom colors. This dialog provides an interface to display standard colors, and allows us to define custom colors.

ColorDialog class represents ColorDialog; provides different properties & methods; we are going to discuss commonly used ones, in this article.

Properties

It has set of properties to display and control the user interface to allow us to select or define the color. Color property is used to get or set the color selected. It is of Color class type.

Color selectedColor = colorDialog.Color;

AnyColor property is used to control whether ColorDialog displays all available basic colors under “Basic colors:” group.

SolidColorOnly property will restrict the user to select only solid colors. No custom colors are allowed to select. Note that, this property is applicable to the systems with 256 or less colors. On other systems, this will not give any effect.

AllowFullOpen property, enables or disables to define custom colors. When this set to false, “Define Custom Colors >>” button will be disabled in the dialog. This button displays the custom color controls to define the custom colors.

CustomColors property will be set with the defined custom colors by the dialog, when we define them. It is an array of Int32 type. Each color comprise of RED, GREEN & BLUE values (RGB). This will be updated, only when allowed to define the custom colors, using AllowFullOpen property.

When the dialog is opened, initially, custom color controls are not visible. We can control this by setting FullOpen property. When AllowFullOpen property is set to false; setting up this property will not give any effect on the dialog.

ShowHelp property is to show or hide Help button on the dialog.

Methods

ShowDialog method is used to display the ColorDialog, and allows to select the color. This method returns DialogResult enum type; of value OK, Cancel etc,; which is depending on the button selected on the dialog.

if (colorDialog.ShowDialog(this) == DialogResult.OK)
	// color selected
else
	// no color selected

Events

ColorDialog triggers an event, HelpRequest, when we click on Help button on the dialog. When ShowHelp property is set to false, this event will not be triggered as Help button will not be visible to the user to click.

Now, this is the time write our code. By putting all together, what we discussed so far, in this article; here is the complete working example;

Here is the screenshot of the Application;

(Raju)