Question

我有一个DropDownList，我想在其中选择一个ID及其名称两次，将其放入DataSet并绑定到DropDownList。以下代码是我的数据绑定。

using (SqlConnection conn1 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
{
    string selectQuery1 = "SELECT [profileID], [profileName], [positionID], [positionName] from vw_profile WHERE memberID=@memberID";
    SqlCommand cmd1 = new SqlCommand(selectQuery1, conn1);
    cmd1.Parameters.AddWithValue("@memberID", memberID);

    SqlDataAdapter da = new SqlDataAdapter();
    da.SelectCommand = cmd1;
    DataSet ds = new DataSet();
    conn1.Open();
    da.Fill(ds);
    conn1.Close();

    chooseProfile.DataSource = ds;
    chooseProfile.DataTextField = "profileName";
    chooseProfile.DataValueField = "profileID";
    chooseProfile.DataBind();

    choosePosition.DataSource = ds;
    choosePosition.DataTextField = "positionName";
    choosePosition.DataValueField = "positionID";
    choosePosition.DataBind();
}

在我的ASP.NET页面上，当用户点击提交时，它意味着获取值并插入表格。

protected void submitReport_Click(object sender, EventArgs e)
{
    using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
    {
        string selectQuery = "SELECT * FROM vw_profile";
        SqlCommand cmd = new SqlCommand(selectQuery, conn);
        conn.Open();
        SqlDataReader viewReader;
        viewReader = cmd.ExecuteReader();
        while (viewReader.Read())
        {
            var memberID = (string)viewReader["memberID"].ToString();

            using (SqlConnection conn1 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
                {
                string selectQuery1 = "SELECT * from vw_profile WHERE memberID=@memberID";
                SqlCommand cmd1 = new SqlCommand(selectQuery1, conn);
                cmd1.Parameters.AddWithValue("@memberID", memberID);
                conn1.Open();
                int submitProfileID = Convert.ToInt32(chooseProfile.SelectedItem.Value);
                int submitPositionID = Convert.ToInt32(choosePosition.SelectedItem.Value);
                DateTime dateTime = DateTime.Now;
                string date = dateTime.GetDateTimeFormats('d')[0];
                int reportNum;
                reportNum = Convert.ToInt32(viewReader["reportNumber"]);
                reportNum++;
                string reportTitle = "#" + reportNum + " - " + date;

                SqlConnection conn2 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString);
                conn2.Open();
                SqlCommand cmd2 = new SqlCommand("INSERT INTO sfgs_reports(profileID,memberID,positionID,reportTitle,reportContent,reportDateStamp,reportNumber) values (@profileID,@memberID,@positionID,@reportTitle,@content,@datestamp,@reportNumber)", conn2);
                cmd2.Parameters.AddWithValue("@content", reportContent.Text);
                cmd2.Parameters.AddWithValue("@memberID", memberID);
                cmd2.Parameters.AddWithValue("@profileID", submitProfileID);
                cmd2.Parameters.AddWithValue("@positionID", submitPositionID);
                cmd2.Parameters.AddWithValue("@reportTitle", reportTitle);
                cmd2.Parameters.AddWithValue("@datestamp", dateTime);
                cmd2.Parameters.AddWithValue("@reportNumber", reportNum);
                cmd2.ExecuteNonQuery();
                conn2.Close();
            }
        }
        conn.Close();
    }
}

现在当有人提交时会发生什么，而不是从我选择的那个抓取Value，而是抓取默认值，如默认情况下显示在DropDownList中的值。任何人都可以在此代码中看到任何可能导致此问题的错误吗？

编辑以显示更新的submitReport_Click方法：

protected void submitReport_Click(object sender, EventArgs e)
{
    using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
    {
        string selectQuery = "SELECT * FROM vw_profile WHERE profileName=@currentUser";
        SqlCommand cmd = new SqlCommand(selectQuery, conn);
        cmd.Parameters.AddWithValue("@currentUser", User.Identity.Name);
        conn.Open();
        SqlDataReader viewReader;
        viewReader = cmd.ExecuteReader();
        while (viewReader.Read())
        {
            var memberID = (string)viewReader["memberID"].ToString();

            if (!Page.IsPostBack)
            {
                using (SqlConnection conn1 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
                {
                    string selectQuery1 = "SELECT [profileID], [profileName], [positionID], [positionName] from vw_profile WHERE memberID=@memberID";
                    SqlCommand cmd1 = new SqlCommand(selectQuery1, conn1);
                    cmd1.Parameters.AddWithValue("@memberID", memberID);

                    SqlDataAdapter da = new SqlDataAdapter();
                    da.SelectCommand = cmd1;
                    DataSet ds = new DataSet();
                    conn1.Open();
                    da.Fill(ds);
                    conn1.Close();

                    chooseProfile.DataSource = ds;
                    chooseProfile.DataTextField = "profileName";
                    chooseProfile.DataValueField = "profileID";
                    chooseProfile.DataBind();

                    choosePosition.DataSource = ds;
                    choosePosition.DataTextField = "positionName";
                    choosePosition.DataValueField = "positionID";
                    choosePosition.DataBind();
                }
            }

            using (SqlConnection conn1 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
            {
                string selectQuery1 = "SELECT * from vw_profile WHERE memberID=@memberID";
                SqlCommand cmd1 = new SqlCommand(selectQuery1, conn);
                cmd1.Parameters.AddWithValue("@memberID", memberID);
                conn1.Open();
                int submitProfileID = Convert.ToInt32(chooseProfile.SelectedItem.Value);
                int submitPositionID = Convert.ToInt32(choosePosition.SelectedItem.Value);
                DateTime dateTime = DateTime.Now;
                string date = dateTime.GetDateTimeFormats('d')[0];  
                int reportNum = 1;
                string reportTitle = "#" + reportNum + " - " + date;

                SqlConnection conn2 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString);
                conn2.Open();
                SqlCommand cmd2 = new SqlCommand("INSERT INTO sfgs_reports(profileID,memberID,positionID,reportTitle,reportContent,reportDateStamp,reportNumber) values (@profileID,@memberID,@positionID,@reportTitle,@content,@datestamp,@reportNumber)", conn2);
                cmd2.Parameters.AddWithValue("@content", reportContent.Text);
                cmd2.Parameters.AddWithValue("@memberID", memberID);
                cmd2.Parameters.AddWithValue("@profileID", submitProfileID);
                cmd2.Parameters.AddWithValue("@positionID", submitPositionID);
                cmd2.Parameters.AddWithValue("@reportTitle", reportTitle);
                cmd2.Parameters.AddWithValue("@datestamp", dateTime);
                cmd2.Parameters.AddWithValue("@reportNumber", reportNum);
                cmd2.ExecuteNonQuery();
                conn2.Close();

                Page.Response.Redirect("default.aspx?ResponseCode=3", false);
            }
        }
        conn.Close();
    }
}

Answer 1

正如你所说的你的DropDown绑定代码在页面加载事件中...把你的代码放在这个块中我相信它会工作..

if(!Page.IsPostBack)
{
using (SqlConnection conn1 = new SqlConnection(ConfigurationManager.ConnectionStrings["SFGSConnectionString1"].ConnectionString))
{
    string selectQuery1 = "SELECT [profileID], [profileName], [positionID], [positionName] from vw_profile WHERE memberID=@memberID";
    SqlCommand cmd1 = new SqlCommand(selectQuery1, conn1);
    cmd1.Parameters.AddWithValue("@memberID", memberID);

    SqlDataAdapter da = new SqlDataAdapter();
    da.SelectCommand = cmd1;
    DataSet ds = new DataSet();
    conn1.Open();
    da.Fill(ds);
    conn1.Close();

    chooseProfile.DataSource = ds;
    chooseProfile.DataTextField = "profileName";
    chooseProfile.DataValueField = "profileID";
    chooseProfile.DataBind();

    choosePosition.DataSource = ds;
    choosePosition.DataTextField = "positionName";
    choosePosition.DataValueField = "positionID";
    choosePosition.DataBind();
}
}

因为当您点击POSTBACK事件后，pageload事件在button click事件运行之后发生。由于您的Page Load事件在您的Button Click DropDownList Binded再次设置为其默认值之前运行。因此，在Binding下拉列表之前检查它不应该是PostBack Call.For我使用Page。 IsPostBack它的PostBack Call或正常通话。

Answer 2

尝试将代码放在这样的代码：

如果（！的IsPostBack） { dropdownlistname.items.clear（）; 做一些事情来约束价值 }

DropDownList选择不正确的值

2 个答案: