Listview not updating base on selected dropdownlist item

Question

User766369706 posted

Hi, I have a listview that is unable to update despite having a method a dropdownlist selectedindexchange method. Below is my code. Please take a look to see what wrong

<asp:ListView runat="server" ID="ListView1" GroupItemCount="5" OnPagePropertiesChanging="ListView1_PagePropertiesChanging">
            <LayoutTemplate>
                <table cellpadding="4" runat="server" id="tblProducts" style="height: 320px">
                    <tr runat="server" id="groupPlaceholder">
                    </tr>
                </table>
                <div class="pagerContent">
                    <asp:DataPager runat="server" ID="DataPager" PagedControlID="ListView1" PageSize="10" OnPreRender="DataPagerProducts_PreRender">
                    <Fields>
                        <asp:NextPreviousPagerField ButtonType="Link" ShowFirstPageButton="true" ShowPreviousPageButton="true" ShowNextPageButton="false" />
                        <asp:NumericPagerField ButtonType="Link" NumericButtonCssClass="btn" CurrentPageLabelCssClass="btn3" ButtonCount="3" />
                        <asp:NextPreviousPagerField ButtonType="Link" ShowLastPageButton="true" ShowNextPageButton="true" ShowPreviousPageButton="false" />
                    </Fields>
                </asp:DataPager>
                </div>
                
            </LayoutTemplate>
            <GroupTemplate>
                <tr runat="server" id="productRow"
                    style="height: 80px">
                    <td runat="server" id="itemPlaceholder"></td>
                </tr>
            </GroupTemplate>
            <ItemTemplate>
                <td valign="top" align="center" style="width: 250px" runat="server">
                    <asp:ImageButton ID="ProductImage" runat="server"
                        ImageUrl='<%# Eval("ProductImage") %>'
                        Height="250px" NavigateUrl='<%#"~/ShoppingProduct.aspx?ProductID="+ Eval("ProductID")%>' />
                    <br />
                    <asp:HyperLink ID="HyperLink1" runat="server" Text='<%# Eval("ProductName")%>'
                        NavigateUrl='<%#"~/ShoppingProduct.aspx?ProductID="+ Eval("ProductID")%>' />
                </td>
            </ItemTemplate>
        </asp:ListView>

Here is the method

 protected void ddlCategory

_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (ddlCategory.SelectedIndex == 0)
        {
            ListView1.DataSource = sBLL.retrieveAllProudctAvailable();
            ListView1.DataBind();
            tbSearchBar.Text = "Default";
        }
        else if (ddlCategory.SelectedIndex != 0)
        {
            tbSearchBar.Text = ddlCategory.SelectedItem.ToString();
            ListView1.DataSource = sDAL.retrieveProductSelectedCategoryAvailable(ddlCategory.SelectedItem.ToString());
            ListView1.DataBind();
        }
  
    }


    public DataSet retrieveProductSelectedCategoryAvailable(String category)
    {
        SqlConnection myConnection = new SqlConnection(strConnectionString);
        string strCommandText = "Select * from Product where ProductCategory = @ProductCategory AND ProductStatus = 'Available'";

        SqlDataAdapter myAdapter = new SqlDataAdapter(strCommandText, myConnection);
        myAdapter.SelectCommand.Parameters.AddWithValue("@ProductCategory", category);
        DataSet myDS = new DataSet();
        myAdapter.Fill(myDS);
        return myDS;
    }

Answer 1

User1577371250 posted

Hi,

Your Page_Load should have the code for binding the ListView inside the postback.

protected void Page_Load(object sender, EventArgs e)
{
     if (!IsPostBack)
     {
          ListView1.DataSource = sBLL.retrieveAllProudctAvailable();
          ListView1.DataBind();
     }
}

Answer 2

User766369706 posted

I did that but it still did not work . Is there any other solution?

Answer 3

User36583972 posted

Hi Alvin096,

From your description, I found your posted code is not very clear. May be you can try the following suggestions.

1: Please debug your code step by step. Check your SelectedIndexChanged event will be executed (if not you can add AutoPostBack="true" in DropDownList).

2: The following tutorial for your reference.

ListView Control in ASP.NET 4.5:

https://chsakell.com/2013/08/30/listview-control-in-asp-net-4-5/

Best Regards,

Yohann Lu