ASP.Net/Asp Control/ListBox

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Add ListItem to ListBox

<form runat="server">
<script language="C#" runat="server">
protected void Page_Load(object o, EventArgs e) {
    if(!IsPostBack) {
        ListItem item;
        item = new ListItem("A");
        languageListBox.Items.Add(item);
        item = new ListItem("B");
        languageListBox.Items.Add(item);
        item = new ListItem("C");
        languageListBox.Items.Add(item);
        languageListBox.Rows = 3;
    }
}
protected void ListBoxSelectionChanged(object o, EventArgs e) {
    bool valueSet = false;
    foreach(ListItem item in languageListBox.Items) {
        if (item.Selected) {
            if(valueSet) {
                favoriteLanguage.Text += ", " + item.Text;
            }
            else {
                favoriteLanguage.Text = item.Text;
                valueSet = true;
            }
        }
    }
}
</script>
<asp:ListBox 
    id="languageListBox"
    runat="server" 
    SelectionMode="multiple" 
    OnSelectedIndexChanged="ListBoxSelectionChanged" /><br />
    Favorite Language: 
    <b><asp:label runat="server" 
                  id="favoriteLanguage" 
                  style="color:blue" 
                  Text="Not Set" /></b><br />
<asp:button runat="server" Text="Submit"/>
</form>



Allowing Multiple Selections in a ListBox Control (VB.net)

<%@ Page Language=VB Debug=true %>
<HTML>
<HEAD>
<TITLE>Allowing Multiple Selections in a ListBox Control</TITLE>
</HEAD>
<form runat="server">
<BR><BR>
Select a Color:<BR>
<BR><BR>
<asp:listbox id="lb1" runat="server" selectionmode="multiple" rows=4>
    <asp:listitem value="Bu">Blue</asp:listitem>
    <asp:listitem value="Re">Red</asp:listitem>
    <asp:listitem value="Gr">Green</asp:listitem>
    <asp:listitem value="Pu" Selected>Purple</asp:listitem>
    <asp:listitem value="Ba">Black</asp:listitem>
    <asp:listitem value="Go" text="Gold"/>
</asp:listbox>
</form>
</BODY>
</HTML>



asp:listbox: On selected index changed

<%@ Page Language=VB Debug=true %>
<script runat=server>
Sub lb1_Changed(Sender As Object, E As EventArgs)
    lb1.BackColor = System.Drawing.Color.FromName(lb1.SelectedItem.Text)
End Sub
</SCRIPT>
<HTML>
<HEAD>
<TITLE>Writing Code that Fires When the Selection Changes in a ListBox Control</TITLE>
</HEAD>
<form runat="server">
<BR><BR>
Select a Color:<BR>
<BR><BR>
<asp:listbox id="lb1" runat="server" autopostback="True" onselectedindexchanged="lb1_Changed" rows=3>
    <asp:listitem value="Bu">Blue</asp:listitem>
    <asp:listitem value="Re">Red</asp:listitem>
    <asp:listitem value="Gr">Green</asp:listitem>
    <asp:listitem value="Pu" >Purple</asp:listitem>
    <asp:listitem value="Ba">Black</asp:listitem>
</asp:listbox>
</form>
</BODY>
</HTML>



Change background color for asp:listbox (VB.net)

<%@ Page Language=VB Debug=true %>
<script runat=server>
Sub lb1_Changed(Sender As Object, E As EventArgs)
    lb1.BackColor = System.Drawing.Color.FromName(lb1.SelectedItem.Text)
End Sub
</SCRIPT>
<HTML>
<HEAD>
<TITLE>Writing Code that Fires When the Selection Changes in a ListBox Control</TITLE>
</HEAD>
<form runat="server">
<BR><BR>
Select a Color:<BR>
<BR><BR>
<asp:listbox id="lb1" runat="server" autopostback="True" onselectedindexchanged="lb1_Changed" rows=3>
    <asp:listitem value="Bu">Blue</asp:listitem>
    <asp:listitem value="Re">Red</asp:listitem>
    <asp:listitem value="Gr">Green</asp:listitem>
    <asp:listitem value="Pu" >Purple</asp:listitem>
    <asp:listitem value="Ba">Black</asp:listitem>
</asp:listbox>
</form>
</BODY>
</HTML>



Get selected index from asp:listbox (VB.net)

<script runat="server" language="vb">
    Sub Page_Load()
    Dim msg As String = "You have selected: <br />"
    If list1.Items(0).Selected Then msg = msg & list1.Items(0).Text & "<br />"
    If list1.Items(1).Selected Then msg = msg & list1.Items(1).Text & "<br />"
    If list1.Items(2).Selected Then msg = msg & list1.Items(2).Text & "<br />"
    Message.Text = msg
  End Sub</script>
<html>
  <head>
    <title>Drop Down List Example</title>
  </head>
  <body>
    <asp:label id="Message" runat="server"/> 
    <br />
    <form runat="server">
    Which city do you wish to look at hotels for?<br /><br />
    <asp:listbox id="list1" runat="server" selectionmode="multiple">
      <asp:listitem>Madrid</asp:listitem>
      <asp:listitem>Oslo</asp:listitem>
      <asp:listitem>Lisbon</asp:listitem>
    </asp:listbox>
    <br /><br /><br /><br />
    <input type="Submit">
    </form>
  </body>
</html>



Get selected index, text and value from asp:listbox (VB.net)

<%@ Page Language=VB Debug=true %>
<script runat=server>
Sub SubmitBtn_Click(Sender As Object, E As EventArgs)
    lblDataSelected.Text = "Selected Text: " _
        & lb1.SelectedItem.Text & "<BR>Selected Value: " _
        & lb1.SelectedItem.Value & "<BR>Selected Index: " _
        & lb1.SelectedIndex       
End Sub
</SCRIPT>
<HTML>
<HEAD>
<TITLE>Creating a Basic ListBox Control</TITLE>
</HEAD>
<form runat="server">
<BR><BR>
<asp:label id="lblDataSelected" runat="server"/>
<BR><BR>
<asp:listbox id="lb1" runat="server" rows=3>
    <asp:listitem value="Bu">Blue</asp:listitem>
    <asp:listitem value="Re">Red</asp:listitem>
    <asp:listitem value="Gr">Green</asp:listitem>
    <asp:listitem value="Pu" Selected>Purple</asp:listitem>
    <asp:listitem value="Ba">Black</asp:listitem>
    <asp:listitem value="Go" text="Gold"/>
</asp:listbox>
<BR><BR>
<asp:button id="butOK" text="OK" type="Submit" onclick="SubmitBtn_Click" runat="server"/>
</form>
</BODY>
</HTML>



Get selected item from ListBox (C#)

<%@ Page Language="C#" %>
<script runat="server">
    void Page_Load()
      {
      string msgCitiesList = "";
    
      if (Page.IsPostBack == true)
    
        if (list1.Items[0].Selected == true)
        {
          msgCitiesList = msgCitiesList + list1.Items[0].Text + "<br />";
        }
    
        if (list1.Items[1].Selected)
        {
          msgCitiesList = msgCitiesList + list1.Items[1].Text + "<br/>";
        }
    
        if (list1.Items[2].Selected)
        {
          msgCitiesList = msgCitiesList + list1.Items[2].Text + "<br />";
        }
    
        if (msgCitiesList != "")
        {
           Message.Text = "You have selected: <br />" + msgCitiesList;
        }
        else
        {
           Message.Text = "";
        }
      }
</script>
<html>
<head>
    <title>List Box Example</title>
</head>
<body>
    <asp:Label id="Message" runat="server"></asp:Label>
    <br />
    Which city do you wish to look at hotels for?<br />
    <form runat="server">
        <asp:listbox id="list1" runat="server" selectionmode="multiple">
            <asp:listitem>A</asp:listitem>
            <asp:listitem>B</asp:listitem>
            <asp:listitem>C</asp:listitem>
        </asp:listbox>
        <br />
        <input type="submit" value="Submit Query" />
    </form>
</body>
</html>



Set static value for asp:listbox (VB.net)

<%@ Page Language=VB Debug=true %>
<HTML>
<HEAD>
<TITLE>Creating a Basic ListBox Control</TITLE>
</HEAD>
<form runat="server">
<BR><BR>
Select a Color:<BR>
<BR><BR>
<asp:listbox id="lb1" runat="server" rows=3>
    <asp:listitem value="Bu">Blue</asp:listitem>
    <asp:listitem value="Re">Red</asp:listitem>
    <asp:listitem value="Gr">Green</asp:listitem>
    <asp:listitem value="Pu" Selected>Purple</asp:listitem>
    <asp:listitem value="Ba">Black</asp:listitem>
    <asp:listitem value="Go" text="Gold"/>
</asp:listbox>
</form>
</BODY>
</HTML>



Using the ListBox to select list items.

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<script runat="server">
    protected void btnAdd_Click(object sender, EventArgs e)
    {
        ListItem item = lstAllProducts.SelectedItem;
        if (item != null)
        {
            lstAllProducts.Items.Remove(item);
            lstFavoriteProducts.ClearSelection();
            lstFavoriteProducts.Items.Add(item);
        }
    }
    protected void btnRemove_Click(object sender, EventArgs e)
    {
        ListItem item = lstFavoriteProducts.SelectedItem;
        if (item != null)
        {
            lstFavoriteProducts.Items.Remove(item);
            lstAllProducts.ClearSelection();
            lstAllProducts.Items.Add(item);
        }
    }
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        foreach (ListItem item in lstFavoriteProducts.Items)
            lblResults.Text += "<li>" + item.Text;
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<body>
    <form id="form1" runat="server">
    <asp:ListBox
        id="lstAllProducts"
        DataSourceID="srcProducts"
        DataTextField="Title"
        DataValueField="Id"
        Runat="server" />
    <asp:Button
        id="btnAdd"
        Text="&gt;"
        ToolTip="Add List Item"
        Runat="server" 
        OnClick="btnAdd_Click" />
    <br />
    <asp:Button
        id="btnRemove"
        Text="&lt;"
        ToolTip="Remove List Item"
        Runat="server" 
        OnClick="btnRemove_Click" />
    </div>
    <asp:ListBox
        id="lstFavoriteProducts"
        Runat="server" />
    </div>
    <asp:Button
        id="btnSubmit"
        Text="Submit Form"
        Runat="server" OnClick="btnSubmit_Click" />
    </p>
    <asp:Label
        id="lblResults"
        EnableViewState="false"
        Runat="server" />
    <asp:SqlDataSource
        id="srcProducts"
        SelectCommand="SELECT Id, Title FROM Products"
        ConnectionString="<%$ ConnectionStrings:Products %>"
        Runat="server" />
    </form>
</body>
</html>
File: Web.config
<configuration>
  <connectionStrings>
    <add name="Products" 
         connectionString="Data Source=.\SQLEXPRESS;
         AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" />
  </connectionStrings>
</configuration>
Источник — «http://nfex.ru/index.php?title=ASP.Net/Asp_Control/ListBox&oldid=2135»