c# - 无法使用 DropDownList 按价格对数据进行排序

Question

我正在尝试按价格对我的数据(在数据列表中)进行排序。这意味着如果用户想要从最贵到最便宜的价格，则有 DropDownList 供用户选择，反之亦然。存储在我的数据库中的价格是根据我的 catID 随机排列的。我写了如下代码，但它没有按照我写的进行排序。我在这里做错了什么？请给我建议。

protected void Page_Load(object sender, EventArgs e)
{

}

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    bindDropDownList();
}

private void bindDropDownList()
{
    DropDownList1.DataTextField = "price";
    DataList1.DataSourceID = null;
    DataList1.DataSource = getReader();
    DropDownList1.DataBind();

}

private SqlDataReader getReader()
{
    SqlDataReader reader = null;

    if(DropDownList1.Text == "-Select-")
    {
      string strConnectionString =
            ConfigurationManager.ConnectionStrings["ProBizConnection"].ConnectionString;
        SqlConnection myConnect = new SqlConnection(strConnectionString);

        string strCommandText ="SELECT * FROM [Category ] WHERE catID<= 20";

        SqlCommand cmd = new SqlCommand(strCommandText, myConnect);
        myConnect.Open();

   reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

    }
    else if (DropDownList1.SelectedValue == "Price - Highest to Lowest")
    {
        string strConnectionString =
            ConfigurationManager.ConnectionStrings["ProBizConnection"].ConnectionString;
        SqlConnection myConnect = new SqlConnection(strConnectionString);

        string strCommandText = "SELECT catID, packageName, price, description1, description2, image1, image2 FROM Category WHERE catID <= 20 ORDER BY price desc";

        SqlCommand cmd = new SqlCommand(strCommandText, myConnect);
        myConnect.Open();

   reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

    }

    else if (DropDownList1.DataTextField == "Price - Lowest to Highest")
    {
        /string strConnectionString =
            ConfigurationManager.ConnectionStrings["ProBizConnection"].ConnectionString;
        SqlConnection myConnect = new SqlConnection(strConnectionString);

        string strCommandText = "SELECT catID, packageName, price, description1, description2, image1, image2 FROM Category WHERE catID <= 20 ORDER BY price";

        SqlCommand cmd = new SqlCommand(strCommandText, myConnect);
        myConnect.Open();

   reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

    }
    return reader;
}

我的 .aspx 代码:

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" AppendDataBoundItems="true" 
            onselectedindexchanged="DropDownList1_SelectedIndexChanged" Height="18px" 
            Width="184px">
            <asp:ListItem>-Select-</asp:ListItem>
            <asp:ListItem>Price - Highest to Lowest</asp:ListItem>
            <asp:ListItem>Price - Lowest to Highest</asp:ListItem>
        </asp:DropDownList>

Answer 1

排序在 Price 列上不正确可能是因为 Price 的数据类型不是小数，可能是 Varchar

所以请将 Price 数据类型更改为 Decimal 以正确排序