Tạo Combobox có nhiều màu trên C#

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using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data; namespace MyComboBox{  /// <summary>  /// Summary description for MyComboBox.  /// </summary>  public class MyComboBox : System.Windows.Forms.Form  {    private System.Windows.Forms.ComboBox comboBox1;    private System.Windows.Forms.Label label1;    private System.Windows.Forms.ComboBox comboBox2;    private System.Windows.Forms.Label label2;    ArrayList colorArray = new ArrayList() ;    ArrayList fontArray  = new ArrayList() ;    /// <summary>    /// Required designer variable.    /// </summary>    private System.ComponentModel.Container components = null;     public MyComboBox()    {      //      // Required for Windows Form Designer support      //      InitializeComponent();       //      // TODO: Add any constructor code after InitializeComponent call      //    }     /// <summary>    /// Clean up any resources being used.    /// </summary>    protected override void Dispose( bool disposing )    {      if( disposing )      {        if (components != null)         {          components.Dispose();        }      }      base.Dispose( disposing );    }     #region Windows Form Designer generated code    /// <summary>    /// Required method for Designer support - do not modify    /// the contents of this method with the code editor.    /// </summary>    private void InitializeComponent()    {      this.comboBox1 = new System.Windows.Forms.ComboBox();      this.label1 = new System.Windows.Forms.Label();      this.comboBox2 = new System.Windows.Forms.ComboBox();      this.label2 = new System.Windows.Forms.Label();      this.SuspendLayout();      //       // comboBox1      //       this.comboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawVariable;      this.comboBox1.ItemHeight = 25;      this.comboBox1.Location = new System.Drawing.Point(16, 40);      this.comboBox1.Name = "comboBox1";      this.comboBox1.Size = new System.Drawing.Size(264, 31);      this.comboBox1.TabIndex = 0;      this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.MyItemSelected);      this.comboBox1.MeasureItem += new System.Windows.Forms.MeasureItemEventHandler(this.comboBox1_MeasureItem);      this.comboBox1.DrawItem += new System.Windows.Forms.DrawItemEventHandler(this.comboBox1_DrawItem);      //       // label1      //       this.label1.Location = new System.Drawing.Point(16, 16);      this.label1.Name = "label1";      this.label1.Size = new System.Drawing.Size(100, 16);      this.label1.TabIndex = 1;      this.label1.Text = "Font Combo Box";      //       // comboBox2      //       this.comboBox2.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;      this.comboBox2.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;      this.comboBox2.ItemHeight = 20;      this.comboBox2.Location = new System.Drawing.Point(16, 104);      this.comboBox2.Name = "comboBox2";      this.comboBox2.Size = new System.Drawing.Size(264, 26);      this.comboBox2.TabIndex = 0;      this.comboBox2.SelectedIndexChanged += new System.EventHandler(this.MyItemSelected);      this.comboBox2.DrawItem += new System.Windows.Forms.DrawItemEventHandler(this.comboBox2_DrawItem);      //       // label2      //       this.label2.Location = new System.Drawing.Point(24, 80);      this.label2.Name = "label2";      this.label2.TabIndex = 2;      this.label2.Text = "Color Combo Box";      //       // MyComboBox      //       this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);      this.ClientSize = new System.Drawing.Size(312, 157);      this.Controls.AddRange(new System.Windows.Forms.Control[] {                                      this.label2,                                      this.label1,                                      this.comboBox1,                                      this.comboBox2});      this.Name = "MyComboBox";      this.Text = "OwnerDraw ComboBox";      this.Load += new System.EventHandler(this.MyComboBox_Load);      this.ResumeLayout(false);     }    #endregion     /// <summary>    /// The main entry point for the application.    /// </summary>    [STAThread]    static void Main()     {      Application.Run(new MyComboBox());    }     private void MyComboBox_Load(object sender, System.EventArgs e)    {        // Fill an array with the different color you wish      // to display in the ComboBox       colorArray.Add(new SolidBrush(Color.Yellow));      colorArray.Add(new SolidBrush(Color.Black));      colorArray.Add(new SolidBrush(Color.Azure));      colorArray.Add(new SolidBrush(Color.Firebrick));      colorArray.Add(new SolidBrush(Color.DarkMagenta));       // Add blank items to the list, since the text we will display      // will be the name of the Color we are painting      comboBox2.Items.Add("");      comboBox2.Items.Add("");      comboBox2.Items.Add("");      comboBox2.Items.Add("");      comboBox2.Items.Add("");           // Fill an array with the different fonts that you will use to display       // items in the other comboBox       fontArray .Add(new Font("Ariel" , 15 , FontStyle.Bold ));      fontArray .Add(new Font("Courier" , 12 , FontStyle.Italic));      fontArray .Add(new Font("Veranda" , 14 , FontStyle.Bold));      fontArray .Add(new Font("System" , 10 , FontStyle.Strikeout));      fontArray .Add(new Font("Century SchoolBook" , 15 , FontStyle.Underline));       // Add the items that in the listBox       comboBox1.Items.Add("Washington");      comboBox1.Items.Add("Houston");      comboBox1.Items.Add("Phoenix");      comboBox1.Items.Add("Dallas");      comboBox1.Items.Add("London");     }     private void comboBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)    {      // Override this function to draw items in the Font comboBox       // Get the Graphics Object (aka. CDC or Device Context Object )      // passed via the DrawItemEventArgs parameter      Graphics g = e.Graphics ;       // Get the bounding rectangle of the item currently being painted      Rectangle r = e.Bounds ;      Font fn = null ;       if ( e.Index >= 0 )       {        // Get the Font object, at the specifid index in the fontArray        fn = (Font)fontArray[e.Index];         // Get the text that we wish to display        string s = (string)comboBox1.Items[e.Index];         // Set the string format options        StringFormat sf = new StringFormat();        sf.Alignment = StringAlignment.Near;         Console.WriteLine(e.State.ToString());        // Draw the rectangle        e.Graphics.DrawRectangle(new Pen(new SolidBrush(Color.Black), 2 ), r );         if ( e.State == ( DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))        {          // if the item is not selected draw it with a different color          e.Graphics.FillRectangle(new SolidBrush(Color.White) , r);          e.Graphics.DrawString( s , fn , new SolidBrush(Color.Black), r ,sf);          e.DrawFocusRectangle();        }        else        {          // if the item is selected draw it with a different color          e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue) , r);          e.Graphics.DrawString( s , fn , new SolidBrush(Color.Red), r ,sf);          e.DrawFocusRectangle();        }      }    }     private void comboBox2_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)    {      // Override this function to draw items in the Color comboBox       // Get the Graphics Object (aka. CDC or Device Context Object )      // passed via the DrawItemEventArgs parameter      Graphics g = e.Graphics ;       // Get the bounding rectangle of the item currently being painted      Rectangle r = e.Bounds ;       if ( e.Index >= 0 )       {        Rectangle rd = r ;         rd.Width = 100 ;                 Rectangle rt = r ;        r.Left = rd.Right ;          // Get the brush object, at the specifid index in the colorArray        SolidBrush b = (SolidBrush)colorArray[e.Index];        // Fill a portion of the rectangle with the selected brush        g.FillRectangle(b  , rd);         // Set the string format options        StringFormat sf = new StringFormat();        sf.Alignment = StringAlignment.Near;         Console.WriteLine(e.State.ToString());                // Draw the rectangle        e.Graphics.DrawRectangle(new Pen(new SolidBrush(Color.Black), 2 ), r );         if ( e.State == ( DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))        {          // if the item is not selected draw it with a different color          e.Graphics.FillRectangle(new SolidBrush(Color.White) , r);          e.Graphics.DrawString( b.Color.Name, new Font("Ariel" , 8 , FontStyle.Bold  ) , new SolidBrush(Color.Black), r ,sf);          e.DrawFocusRectangle();        }        else        {          // if the item is selected draw it with a different color          e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue) , r);          e.Graphics.DrawString( b.Color.Name, new Font("Veranda" , 12 , FontStyle.Bold  ) , new SolidBrush(Color.Red), r ,sf);          e.DrawFocusRectangle();        }      }    }     private void MyItemSelected(object sender, System.EventArgs e)    {      // UnBox the sender. Since both the ComboBox controls use the same      // events to handle the selection of item from the list       ComboBox cb = null ;      if ( sender.Equals(comboBox1))        cb = comboBox1;       else        cb = comboBox2;             // Get the index of the Item Selected            int x = cb.SelectedIndex ;       string str = "";      // Get the Text of the item selected      if ( sender.Equals(comboBox1))      {        str = "Item Selected is = " + (string)cb.Items[x];      }      else      {        SolidBrush br = (SolidBrush)colorArray[x];        str = "Color Selected is = " + br.Color.Name;      }            MessageBox.Show(str,"ComboBox Item");    }     private void comboBox1_MeasureItem(object sender, System.Windows.Forms.MeasureItemEventArgs e)    {      // For the comboBox with OwnerDrawVariable property      // Display every second item with a height of 45      if ( e.Index%2 == 0  )      {        e.ItemHeight = 45 ;        e.ItemWidth = 20 ;       }      else      {        // Display all other items with a height of 25        e.ItemHeight = 25 ;        e.ItemWidth = 10 ;       }    }  }}

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