ComboBox實現聯想輸入

 

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Auto_Complete_ComboBox
{
 /// <summary>
 /// Summary description for Form1.
 /// </summary>
 public class frmAutoCompleteComboBox : System.Windows.Forms.Form
 {
  internal System.Windows.Forms.Label lblTest;
  internal System.Windows.Forms.CheckBox chkLimitToList;
  internal System.Windows.Forms.CheckBox chkAutoComplete;
  internal System.Windows.Forms.ComboBox cbAutoComplete;
  /// <summary>
  /// Required designer variable.
  /// </summary>
  private System.ComponentModel.Container components = null;

  public frmAutoCompleteComboBox()
  {
   //
   // 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.lblTest = new System.Windows.Forms.Label();
   this.chkLimitToList = new System.Windows.Forms.CheckBox();
   this.chkAutoComplete = new System.Windows.Forms.CheckBox();
   this.cbAutoComplete = new System.Windows.Forms.ComboBox();
   this.SuspendLayout();
   //
   // lblTest
   //
   this.lblTest.AutoSize = true;
   this.lblTest.Location = new System.Drawing.Point(8, 151);
   this.lblTest.Name = "lblTest";
   this.lblTest.Size = new System.Drawing.Size(0, 16);
   this.lblTest.TabIndex = 7;
   //
   // chkLimitToList
   //
   this.chkLimitToList.Checked = true;
   this.chkLimitToList.CheckState = System.Windows.Forms.CheckState.Checked;
   this.chkLimitToList.FlatStyle = System.Windows.Forms.FlatStyle.System;
   this.chkLimitToList.Location = new System.Drawing.Point(208, 39);
   this.chkLimitToList.Name = "chkLimitToList";
   this.chkLimitToList.Size = new System.Drawing.Size(80, 16);
   this.chkLimitToList.TabIndex = 2;
   this.chkLimitToList.Text = "Limit to List";
   //
   // chkAutoComplete
   //
   this.chkAutoComplete.Checked = true;
   this.chkAutoComplete.CheckState = System.Windows.Forms.CheckState.Checked;
   this.chkAutoComplete.FlatStyle = System.Windows.Forms.FlatStyle.System;
   this.chkAutoComplete.Location = new System.Drawing.Point(208, 15);
   this.chkAutoComplete.Name = "chkAutoComplete";
   this.chkAutoComplete.Size = new System.Drawing.Size(96, 16);
   this.chkAutoComplete.TabIndex = 1;
   this.chkAutoComplete.Text = "Auto Complete";
   //
   // cbAutoComplete
   //
   this.cbAutoComplete.Items.AddRange(new object[] {
                "Aaron Alex",        
                "Zernik Uri",
                "Ziarko Wojciech P.",
                "Zicari Roberto"});
   this.cbAutoComplete.Location = new System.Drawing.Point(16, 15);
   this.cbAutoComplete.MaxDropDownItems = 10;
   this.cbAutoComplete.Name = "cbAutoComplete";
   this.cbAutoComplete.Size = new System.Drawing.Size(176, 21);
   this.cbAutoComplete.TabIndex = 0;
   this.cbAutoComplete.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.cbAutoComplete_KeyPress);
   //
   // frmAutoCompleteComboBox
   //
   this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
   this.ClientSize = new System.Drawing.Size(312, 182);
   this.Controls.Add(this.lblTest);
   this.Controls.Add(this.chkLimitToList);
   this.Controls.Add(this.chkAutoComplete);
   this.Controls.Add(this.cbAutoComplete);
   this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
   this.MaximizeBox = false;
   this.Name = "frmAutoCompleteComboBox";
   this.Text = "Auto Complete ComboBox - Example";
   this.ResumeLayout(false);

  }
  #endregion

  /// <summary>
  /// The main entry point for the application.
  /// </summary>
  [STAThread]
  static void Main()
  {
   Application.Run(new frmAutoCompleteComboBox());
  }

  private void cbAutoComplete_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
  {
   if (this.chkAutoComplete.Checked)
    this.AutoComplete(this.cbAutoComplete, e, this.chkAutoComplete.Checked);
  }

       
  
  // AutoComplete
  public void AutoComplete(ComboBox cb, System.Windows.Forms.KeyPressEventArgs e)
  {
   this.AutoComplete(cb, e, false);
  }

  public void AutoComplete(ComboBox cb, System.Windows.Forms.KeyPressEventArgs e, bool blnLimitToList)
  {
   string strFindStr = "";

   if (e.KeyChar == (char)8)
   {
    if (cb.SelectionStart <= 1)
    {
     cb.Text = "";
     return;
    }

    if (cb.SelectionLength == 0)
     strFindStr = cb.Text.Substring(0, cb.Text.Length - 1);
      else
     strFindStr = cb.Text.Substring(0, cb.SelectionStart - 1);
     }
   else
   {
    if (cb.SelectionLength == 0)
     strFindStr = cb.Text + e.KeyChar;
    else
     strFindStr = cb.Text.Substring(0, cb.SelectionStart) + e.KeyChar;
   }

   int intIdx = -1;

   // Search the string in the ComboBox list.
   
   intIdx = cb.FindString(strFindStr);
 
   if (intIdx != -1)
   {
    cb.SelectedText = "";
    cb.SelectedIndex = intIdx;
    cb.SelectionStart = strFindStr.Length;
    cb.SelectionLength = cb.Text.Length;
    e.Handled = true;
   }
   else
   {
    e.Handled = blnLimitToList;
   }

  }

 }
}