How to Move List Box Items to another List Box in C#.

Introduction

An article to demonstrate How to Move List Box Items to another List Box in ASP.NET and C#.

About the solution

In many web applications it is required use list boxes. Sometimes it is necessary to select some items from one list to another. In this case we use two listboxes. This article demonstrates how to perform basic operations in such case. This operations include Add/Remove/Add All / Remove All functionalities.

Background

List Box control is a standard control in Asp.net. It is similar to a dropdownlist.

Code Snippets

<p style="TEXT-ALIGN: justify">Code to add selected item to the list 


</p>

<p style="TEXT-ALIGN: justify">Protected void btnAdd_Click(object sender, EventArgs e)
 {
 if (lstEmployees.SelectedIndex > -1)
   {
     string _value = lstEmployees.SelectedItem.Value; //Gets the value of  items in list.
     string _text = lstEmployees.SelectedItem.Text;  // Gets the Text of items in the list.  
     ListItem item = new ListItem (); //create a list item
     item.Text = _text;               //Assign the values to list item   
     item.Value = _value;
     lstSelectedEmployees.Items.Add(item); //Add the list item to the selected list of employees   
     lstEmployees.Items.Remove(item); //Remove the details from employee list   
   }

<p style="TEXT-ALIGN: justify">}

Code to Remove  selected item from the list 
 
protected void btnRemove_Click(object sender, EventArgs e)
    {
        if (lstSelectedEmployees.SelectedIndex > -1)
        {
            string _value = lstSelectedEmployees.SelectedItem.Value; //Gets the value of items in list.
            string _text = lstSelectedEmployees.SelectedItem.Text;  // Gets the Text of items in the list.  
            ListItem item = new ListItem(); //create a list item
            item.Text = _text;               //Assign the values to list item   
            item.Value = _value;
            lstSelectedEmployees.Items.Remove(item); //Remove from the selected list
            lstEmployees.Items.Add(item); //Add in the Employee list 

        }

    }

Code to Remove All   items from the list 

   protected void btnReset_Click(object sender, EventArgs e)
    {
        int _count=lstSelectedEmployees.Items.Count;
        if (_count != 0)
        {
         for (int i = 0; i < _count; i++)
            {
               ListItem item = new ListItem();
               item.Text = lstSelectedEmployees.Items[i].Text;
                item.Value = lstSelectedEmployees.Items[i].Value;
                lstEmployees.Items.Add(item);   
            }
        }

       lstSelectedEmployees.Items.Clear();//clear the items  
   }

 
 Code to Add All   items to the list 


  protected void btnAddAll_Click(object sender, EventArgs e)
    {
        int _count = lstEmployees.Items.Count;
        if (_count != 0)
         {
            for (int i = 0; i < _count; i++)
             {
               ListItem item = new ListItem();
               item.Text = lstEmployees.Items[i].Text;
               item.Value = lstEmployees.Items[i].Value;
               //Add the item to selected employee list
               lstSelectedEmployees.Items.Add(item);  
          }

        }

      //clear employee list
        lstEmployees.Items.Clear();  

  }


</p>