Avoid data redundancy in ASP.NET page

I have an asp.net page which uses a listview to show 2 columns of data. The first column has just labels and the second one has dropdowns.

My concern is, the dropdowns in second column has same item开发者_如何学Pythons 100% of the time, they never change and since it is databound, and datasource to these dropdown is also same. As these dropdowns are in a list view this repetition happens on each row added to my list view!

So, I was thinking of removing this data redundancy being transported over the wire. Any ideas?

If you are using an ObjectDataSource, you can reduce the load time enabling the cache:

   <asp:objectdatasource ID="ObjectDataSource1" runat="server"
      EnableCaching="true" .... >
   </asp:objectDataSource>

If your datasource is a database call then you can reduce that by storing the result of the call in a DataView object, and then binding your dropdowns to that object rather than making the call to the database for each dropdown.

You could use the following approach:

It loads the items in to the very first DropDownList and then uses JQuery to retrieve that DropDownList and and replicate the items into all of the others.

Markup

<div id="listViewContainer">
    <asp:ListView ID="listView1" runat="server">
        <ItemTemplate>
            <div><asp:DropDownList ID="dropDownList1" runat="server"></asp:DropDownList></div>
        </ItemTemplate>
    </asp:ListView>        
</div>

Script

$(function () {
    var sourceDropDown = $('#listViewContainer').find('select').first();

    $('#listViewContainer').find('select').not(sourceDropDown).each(function () {
        var dropdown = $(this);
        dropdown.find('option').remove();

        sourceDropDown.find('option').each(function () {
            var option = $(this);
            dropdown.append($('<option />').text(option.text()).val(option.val()));
        });
    });
});

Code

    void listView1_ItemDataBound(object sender, ListViewItemEventArgs e)
    {
        if (e.Item.DisplayIndex == 0)
        {
            DropDownList dropDownList1 = (DropDownList)e.Item.FindControl("dropDownList1");
            dropDownList1.DataSource = dataTable;
            dropDownList1.DataTextField = "Text";
            dropDownList1.DataValueField = "Value";
            dropDownList1.DataBind();
        }
    }

Hope this helps.