C# ListBox.FindString方法代码示例

private void FindMyString(string searchString)
{
   // Ensure we have a proper string to search for.
   if (!string.IsNullOrEmpty(searchString))
   {
      // Find the item in the list and store the index to the item.
      int index = listBox1.FindString(searchString);
      // Determine if a valid index is returned. Select the item if it is valid.
      if (index != -1)
         listBox1.SetSelected(index,true);
      else
         MessageBox.Show("The search string did not match any items in the ListBox");
   }
}

private void FindAllOfMyString(string searchString)
{
   // Set the SelectionMode property of the ListBox to select multiple items.
   listBox1.SelectionMode = SelectionMode.MultiExtended;
   
   // Set our intial index variable to -1.
   int x =-1;
   // If the search string is empty exit.
   if (searchString.Length != 0)
   {
      // Loop through and find each item that matches the search string.
      do
      {
         // Retrieve the item based on the previous index found. Starts with -1 which searches start.
         x = listBox1.FindString(searchString, x);
         // If no item is found that matches exit.
         if (x != -1)
         {
            // Since the FindString loops infinitely, determine if we found first item again and exit.
            if (listBox1.SelectedIndices.Count > 0)
            {
               if(x == listBox1.SelectedIndices[0])
                  return;
            }
            // Select the item in the ListBox once it is found.
            listBox1.SetSelected(x,true);
         }
      }while(x != -1);
   }
}

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa

Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/

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

namespace AddControls
{
  /// <summary>
  /// Summary description for AddControls.
  /// </summary>
  public class AddControls : System.Windows.Forms.Form
  {
    private System.Windows.Forms.ListBox listBox1;
    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.TextBox textBox1;
    private System.Windows.Forms.Button button2;
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ComponentModel.Container components = null;

    public AddControls()
    {
      //
      // 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.button2 = new System.Windows.Forms.Button();
      this.textBox1 = new System.Windows.Forms.TextBox();
      this.button1 = new System.Windows.Forms.Button();
      this.listBox1 = new System.Windows.Forms.ListBox();
      this.SuspendLayout();
      // 
      // button2
      // 
      this.button2.Location = new System.Drawing.Point(160, 240);
      this.button2.Name = "button2";
      this.button2.Size = new System.Drawing.Size(96, 24);
      this.button2.TabIndex = 3;
      this.button2.Text = "Cancel";
      this.button2.Click += new System.EventHandler(this.button2_Click);
      // 
      // textBox1
      // 
      this.textBox1.Location = new System.Drawing.Point(38, 200);
      this.textBox1.Name = "textBox1";
      this.textBox1.Size = new System.Drawing.Size(216, 20);
      this.textBox1.TabIndex = 1;
      this.textBox1.Text = "";
      // 
      // button1
      // 
      this.button1.Location = new System.Drawing.Point(48, 240);
      this.button1.Name = "button1";
      this.button1.Size = new System.Drawing.Size(80, 24);
      this.button1.TabIndex = 2;
      this.button1.Text = "Add Item";
      this.button1.Click += new System.EventHandler(this.button1_Click);
      // 
      // listBox1
      // 
      this.listBox1.Location = new System.Drawing.Point(38, 32);
      this.listBox1.Name = "listBox1";
      this.listBox1.Size = new System.Drawing.Size(216, 147);
      this.listBox1.TabIndex = 0;
      // 
      // Form1
      // 
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                      this.button2,
                                      this.button1,
                                      this.textBox1,
                                      this.listBox1});
      this.Name = "AddControls";
      this.Text = "AddControls";
      this.ResumeLayout(false);

    }
    #endregion

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

    private void button1_Click(object sender, System.EventArgs e)
    {
      if (textBox1.Text == "")
        return;
      string strAdd = textBox1.Text;
      if (listBox1.FindString (strAdd, -1) < 0)
      {
        listBox1.Items.Add (strAdd);
        textBox1.Text = "";
        textBox1.Focus ();
        return;
      }
      MessageBox.Show ("\"" + strAdd + "\" is already in the list box", "Duplicate");
    }

    private void button2_Click(object sender, System.EventArgs e)
    {
      Application.Exit();
    }
  }
}