Saving Multiple Values to Hidden Filed

Question

I am using below drop-down list that allows user to select multiple values.

How can i save the selected values from drop-down list to hidden field.

Drop Down List

<asp:DropDownList ID="DropDownList1" CssClass="form-control chosen-select" multiple data-placeholder="Multiple Select" runat="server" DataSourceID="SqlDataSource1" DataTextField="Product_Name" DataValueField="Pro_ID"></asp:DropDownList>

HiddenField

<asp:HiddenField ID="hdnSearchParam" runat="server" />

Answer 1

You can use like this:

string selectedTexts="";
foreach (ListItem item in DropDownList1.Items)
{
    if (item.Selected)
    {
        selectedTexts += item.Text + " : " + item.Value + "\\n";
    }
}
hdnSearchParam.Value= selectedTexts;