C# Color.FromKnownColor方法代码示例

public void KnownColorBrightnessExample1(PaintEventArgs e)
{
    Graphics     g = e.Graphics;
             
    // Color structures. One is a variable used for temporary storage. The other
    // is a constant used for comparisons.
    Color   someColor = Color.FromArgb(0);
    Color   redShade = Color.FromArgb(255, 200, 0, 100);
             
    // Array to store KnownColor values that match the brightness of the
    // redShade color.
    KnownColor[]  colorMatches = new KnownColor[15];
     
    // Number of matches found.
    int  count = 0;   
          
    // Iterate through the KnownColor enums until 15 matches are found.
    for (KnownColor enumValue = 0;
        enumValue <= KnownColor.YellowGreen && count < 15; enumValue++)
    {
        someColor = Color.FromKnownColor(enumValue);
        if (someColor.GetBrightness() == redShade.GetBrightness())
            colorMatches[count++] = enumValue;
    }
             
    // Display the redShade color and its argb value.
    SolidBrush  myBrush1 = new SolidBrush(redShade);
    Font        myFont = new Font("Arial", 12);
    int         x = 20;
    int         y = 20;
    someColor = redShade;
    g.FillRectangle(myBrush1, x, y, 100, 30);
    g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 120, y);
             
    // Iterate through the matches that were found and display each color that
    // Corresponds with the enum value in the array. also display the name of
    // The KnownColor.
    for (int i = 0; i < count; i++)
    {
        y += 40;
        someColor = Color.FromKnownColor(colorMatches[i]);
        myBrush1.Color = someColor;
        g.FillRectangle(myBrush1, x, y, 100, 30);
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 120, y);
    }
}

//引入命名空间
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace ColorChanger
{
    public class ColorChanger : System.Windows.Forms.Form
    {
        internal System.Windows.Forms.Label lblSaturation;
        internal System.Windows.Forms.Label lblHue;
        internal System.Windows.Forms.Label lblBrightness;
        internal System.Windows.Forms.Label Label1;
        internal System.Windows.Forms.ListBox lstColors;

        private System.ComponentModel.Container components = null;

        public ColorChanger()
        {
            InitializeComponent();
        }

        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #region Windows Form Designer generated code
        private void InitializeComponent()
        {
            this.lblSaturation = new System.Windows.Forms.Label();
            this.lblHue = new System.Windows.Forms.Label();
            this.lblBrightness = new System.Windows.Forms.Label();
            this.Label1 = new System.Windows.Forms.Label();
            this.lstColors = new System.Windows.Forms.ListBox();
            this.SuspendLayout();

            this.lblSaturation.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
            this.lblSaturation.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.lblSaturation.FlatStyle = System.Windows.Forms.FlatStyle.System;
            this.lblSaturation.Location = new System.Drawing.Point(264, 56);
            this.lblSaturation.Name = "lblSaturation";
            this.lblSaturation.Size = new System.Drawing.Size(136, 20);
            this.lblSaturation.TabIndex = 9;
            this.lblSaturation.Text = " Saturation";

            this.lblHue.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
            this.lblHue.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.lblHue.FlatStyle = System.Windows.Forms.FlatStyle.System;
            this.lblHue.Location = new System.Drawing.Point(264, 32);
            this.lblHue.Name = "lblHue";
            this.lblHue.Size = new System.Drawing.Size(136, 20);
            this.lblHue.TabIndex = 8;
            this.lblHue.Text = " Hue";

            this.lblBrightness.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
            this.lblBrightness.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.lblBrightness.FlatStyle = System.Windows.Forms.FlatStyle.System;
            this.lblBrightness.Location = new System.Drawing.Point(264, 8);
            this.lblBrightness.Name = "lblBrightness";
            this.lblBrightness.Size = new System.Drawing.Size(136, 20);
            this.lblBrightness.TabIndex = 7;
            this.lblBrightness.Text = " Brightness";

            this.Label1.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
            this.Label1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.Label1.FlatStyle = System.Windows.Forms.FlatStyle.System;
            this.Label1.Location = new System.Drawing.Point(8, 8);
            this.Label1.Name = "Label1";
            this.Label1.Size = new System.Drawing.Size(200, 20);
            this.Label1.TabIndex = 6;
            this.Label1.Text = " Choose a Background Color:";

            this.lstColors.Location = new System.Drawing.Point(8, 36);
            this.lstColors.Name = "lstColors";
            this.lstColors.Size = new System.Drawing.Size(200, 238);
            this.lstColors.TabIndex = 5;
            this.lstColors.SelectedIndexChanged += new System.EventHandler(this.lstColors_SelectedIndexChanged);

            this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
            this.ClientSize = new System.Drawing.Size(472, 290);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.lblSaturation,
                                                                          this.lblHue,
                                                                          this.lblBrightness,
                                                                          this.Label1,
                                                                          this.lstColors});
            this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
            this.Name = "ColorChanger";
            this.Text = "Color Changer";
            this.Load += new System.EventHandler(this.ColorChanger_Load);
            this.ResumeLayout(false);

        }
        #endregion
        [STAThread]
        static void Main() 
        {
            Application.Run(new ColorChanger());
        }

        private void ColorChanger_Load(object sender, System.EventArgs e)
        {
            string[] colorNames;
            colorNames = System.Enum.GetNames(typeof(KnownColor));

            lstColors.Items.AddRange(colorNames);
        }

        private void lstColors_SelectedIndexChanged(object sender, System.EventArgs e)
        {
            KnownColor selectedColor;
            selectedColor = (KnownColor)System.Enum.Parse(typeof(KnownColor), lstColors.Text);
            
            this.BackColor = System.Drawing.Color.FromKnownColor(selectedColor);
            
            lblBrightness.Text = "Brightness = " +this.BackColor.GetBrightness().ToString();
            lblHue.Text = "Hue = " + this.BackColor.GetHue().ToString();
            lblSaturation.Text = "Saturation = " + this.BackColor.GetSaturation().ToString();
        }
    }
}