Refer this example.
HTML
<asp:TextBox ID="TextBox1" runat="server" />
<asp:ListBox ID="ListBox1" runat="server" SelectionMode="Multiple">
<asp:ListItem Text="MH" />
<asp:ListItem Text="KA" />
<asp:ListItem Text="MP" />
</asp:ListBox>
<asp:ListBox ID="ListBox2" runat="server" SelectionMode="Multiple">
<asp:ListItem Text="MUMBAI" />
<asp:ListItem Text="DELHI" />
<asp:ListItem Text="KOLKATA" />
</asp:ListBox>
C#
protected void Save(object sender, EventArgs e)
{
string column1 = string.Empty;
string listBox1Values = string.Empty;
string listBox2Values = string.Empty;
string column2 = string.Empty;
string column3 = string.Empty;
column1 = this.TextBox1.Text;
foreach (ListItem item in this.ListBox1.Items)
{
if (item.Selected)
{
listBox1Values = listBox1Values + item.Text + ",";
}
}
foreach (ListItem item in this.ListBox2.Items)
{
if (item.Selected)
{
listBox2Values = listBox2Values + item.Text + ",";
}
}
if (!string.IsNullOrEmpty(listBox1Values))
{
column2 = listBox1Values.Remove(listBox1Values.LastIndexOf(","));
}
if (!string.IsNullOrEmpty(listBox2Values))
{
column3 = listBox1Values.Remove(listBox2Values.LastIndexOf(","));
}
}
Now pass the column1, column2, column3 to your WCF and insert it.