C# Color Examples: FromKnownColor, FromName

Explore the Color type, using the FromKnownColor and FromName methods.

Color. This struct provides a standard way to specify (and mutate) colors in the C# language. By adding a reference to the System.Drawing assembly, you can access this type and avoid writing your own color routines.Struct

First, let's examine a program that uses a named color property. It then accesses several instance properties on the variable and also calls methods. You can acquire many known colors by using the named properties on the Color type.

Tip: Colors can be represented as ARGB values, which store the alpha transparency, as well as the red, green and blue values.

Bytes: These values are stored as bytes which gives them a range of 0 to 255 inclusive.

Byte

Info: If you try to execute this program and it won't compile, add the System.Drawing assembly through the interface in Visual Studio.

C# program that demonstrates Color type using System; using System.Drawing; class Program { static void Main() { // Get the AliceBlue color. Color color = Color.AliceBlue; // Write some details about the color. Console.WriteLine(color); Console.WriteLine(color.ToArgb()); Console.WriteLine(color.A); Console.WriteLine(color.R); Console.WriteLine(color.G); Console.WriteLine(color.B); Console.WriteLine(color.GetBrightness()); Console.WriteLine(color.GetHue()); Console.WriteLine(color.GetSaturation()); } } Output Color [AliceBlue] -984833 255 240 248 255 0.9705882 208 1

Known colors. Occasionally, you may have a known color and want to acquire a Color struct from it for usage elsewhere. For example, you can query the system for the color of the menu text, using the KnownColor.MenuText enum.

And: Then convert it into a regular color. This lets you examine the components of the color programmatically.

C# program that uses known colors using System; using System.Drawing; class Program { static void Main() { // You can see what the menu text color is. Color color = Color.FromKnownColor(KnownColor.MenuText); // All values are zero so it is black. Console.WriteLine(color.R); Console.WriteLine(color.G); Console.WriteLine(color.B); } } Output 0 0 0

Convert. It is possible to represent colors as an integer that represents the byte values of the ARGB values. Each of those values is one byte. The four bytes together constitute a single 32-bit integer.

Tip: You can persist the ARGB integer to text files or databases to save storage space. It will occupy less memory too.

And: Please notice how the ToArgb() and FromArgb() methods are used to go back and forth.

C# program that uses ARGB values using System.Drawing; class Program { static void Main() { // Get ARGB of black. int argb = Color.Black.ToArgb(); // Get the color black by using the argb integer. Color color = Color.FromArgb(argb); } }

FromName. In some cases, you may have to convert from a string to a color type. For example, if you accept user input and the user types the word "white", you can convert this into a real color and use it with the Color.FromName method.

Note: This won't work for color names that are not recognized in the list of properties.

C# program that uses FromName and string using System; using System.Drawing; class Program { static void Main() { // Create the color from a string. Color white = Color.FromName("white"); // Color will have appropriate R G B values. Console.WriteLine(white.R); Console.WriteLine(white.G); Console.WriteLine(white.B); } } Output 255 255 255

Empty colors. The Color type is a struct type, and so cannot be set to null. Instead of using null, please use the Color.Empty value. Then, whenever you want to see if the color is still empty, acquire the IsEmpty instance property on the variable.

Here: This example shows one case where the color is empty, and one case where the color is not empty.

C# program that uses empty colors using System; using System.Drawing; class Program { static void Main() { // Color is a struct so it cannot be null. // ... Use Color.Empty instead. Color color = Color.Empty; Console.WriteLine(color.IsEmpty); color = Color.Black; Console.WriteLine(color.IsEmpty); } } Output True False

Windows Forms. A common place to use the Color type is in the Windows Forms framework. The WPF framework also uses Color instances. Forms require the Color type for when you want to set their backgrounds and foregrounds.ForeColor, BackColor

Example: We use the Color.FromName method to convert the string value into an actual color. We then set the form's background to that color.

C# program that uses BackColor property using System; using System.Drawing; using System.Windows.Forms; namespace WindowsFormsApplication16 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { // You can assign colors to the BackColor property in Windows Forms. this.BackColor = Color.FromName("green"); } } }

Named colors. There are many different known and named colors in the .NET Framework. These are accessible through static properties on the Color type. Please see the first example to see how to get the color values.Color Table

Summary. By providing a unified interface for acquiring and mutating color values, the Color type fills a useful niche in the .NET Framework. It is found in the System.Drawing namespace and assembly.

So: You can access known colors, convert colors to integers, parse colors, and generally make the world a brighter place with this type.

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C# Color Examples: FromKnownColor, FromName

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