Question

我正在使用C＃ASP.NET，并且我有一个提交页面，当您单击添加产品链接时，会打开一个弹出“添加产品”页面，其中包含可添加到的产品的下拉列表提交。业务规则规定每个产品在任何提交中只能有一个实例，所以我运行了两个单独的switch case语句，一个用于在弹出窗口中选择后从下拉列表中删除项目，另一个用于查询db以确定是否有任何已与提交相关联的产品，如果是，请从下拉列表中删除这些选项。用户从下拉列表中选择一个项目后，该产品的面板将显示为用户输入。

这两种开关盒都起作用，因为它们消除了不应该有的物品，但是由于我放入了查询过的开关盒，所以在选择时面板不再可见。当我移除查询的开关盒时，面板在选择时会变得可见，但是已经与提交相关联的产品仍然可以在下拉列表中找到。

我知道这里有一个冲突，但是我很喜欢它是什么，因为这是我第一次参加编程。代码如下。请忽略查询本身;这是一个非主动的培训项目，我的处理程序禁止参数化，因为他希望我先学习基础知识。我理解注射漏洞。

    public partial class AddProduct : System.Web.UI.Page
{


protected void BtnAddProduct_Click(object sender, EventArgs e)
{
    switch (DdlProductList.SelectedValue)
    {
        case "1":
            PanelEpl.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "2":
            PanelProf.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "3":
            PanelCrime.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "4":
            PanelFid.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "5":
            PanelNotProf.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "6":
            PanelPriv.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "7":
            PanelPub.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        default:

                break;
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {

        string x = Request.QueryString["SubId"];
        string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
        string displayQuery = "SELECT CustName, CustAdd, CustCity, CustState, CustZip FROM Customer WHERE SubId =" + x;
        string broQuery = "SELECT EntityType FROM Broker WHERE SubId =" + x;
        string ddlQuery = "SELECT ProductId FROM SubmissionProducts WHERE SubmissionId =" + x;
        using (SqlConnection displayConn = new SqlConnection(connectionString))
        {
            displayConn.Open();
            SqlCommand DlistCmd = new SqlCommand(ddlQuery, displayConn);

            using (SqlDataReader Ddldr = DlistCmd.ExecuteReader())
            {
                while (Ddldr.Read())
                {

                    switch (Ddldr.GetInt32(0))
                    {
                        case 1:
                            DdlProductList.Items.RemoveAt(1);
                            break;
                        case 2:
                            DdlProductList.Items.RemoveAt(2);
                            break;
                        case 3:
                            DdlProductList.Items.RemoveAt(3);
                            break;
                        case 4:
                            DdlProductList.Items.RemoveAt(4);
                            break;
                        case 5:
                            DdlProductList.Items.RemoveAt(5);
                            break;
                        case 6:
                            DdlProductList.Items.RemoveAt(6);
                            break;
                        case 7:
                            DdlProductList.Items.RemoveAt(7);
                            break;
                        default:
                            break;
                    }

                }

            }

Answer 1

我认为你没有考虑Page backback状态。将page_load代码放在If(!IsPostBack)条件下：

protected void Page_Load(object sender, EventArgs e)
{
 If(!IsPostBack)
 {
    string x = Request.QueryString["SubId"];
    string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
    string displayQuery = "SELECT CustName, CustAdd, CustCity, CustState, CustZip FROM Customer WHERE SubId =" + x;
    string broQuery = "SELECT EntityType FROM Broker WHERE SubId =" + x;
    string ddlQuery = "SELECT ProductId FROM SubmissionProducts WHERE SubmissionId =" + x;
    using (SqlConnection displayConn = new SqlConnection(connectionString))
    {
        displayConn.Open();
        SqlCommand DlistCmd = new SqlCommand(ddlQuery, displayConn);

        using (SqlDataReader Ddldr = DlistCmd.ExecuteReader())
        {
            while (Ddldr.Read())
            {

                switch (Ddldr.GetInt32(0))
                {
                    case 1:
                        DdlProductList.Items.RemoveAt(1);
                        break;
                    case 2:
                        DdlProductList.Items.RemoveAt(2);
                        break;
                    case 3:
                        DdlProductList.Items.RemoveAt(3);
                        break;
                    case 4:
                        DdlProductList.Items.RemoveAt(4);
                        break;
                    case 5:
                        DdlProductList.Items.RemoveAt(5);
                        break;
                    case 6:
                        DdlProductList.Items.RemoveAt(6);
                        break;
                    case 7:
                        DdlProductList.Items.RemoveAt(7);
                        break;
                    default:
                        break;
                }

            }

        }

切换案例冲突与下拉列表可用性/面板可见性？

1 个答案: