Question

我目前有一个复选框，根据数据库中的值保持选中或取消选中。我希望复选框能够动态更改，以便在加载页面时检查它并将其更改为未选中，它将更改数据库值以及重定向到其他页面。现在我无法更改数据库值并重定向到其他页面。我目前已将autopost设置为true。

protected void Page_Load(object sender, EventArgs e)
{



    using (SqlConnection dataConnection = new SqlConnection(@"Data Source=184.168.47.21;Initial Catalog=RecruitPursuit;Persist Security Info=True;User ID=RecruitPursuit;Password=Recruit20!8"))
    using (SqlCommand dataCommand =
            new SqlCommand("select SportHasPositions from Sport Where Sport_Id = @Sport_Id", dataConnection))

    {
        SqlParameter param2 = new SqlParameter();
        param2.ParameterName = "@Sport_Id";
        param2.Value = Session["SportID"];
        dataCommand.Parameters.Add(param2);

        dataConnection.Open();
        sportHasPositions = dataCommand.ExecuteScalar().ToString();
    }

    if (sportHasPositions == "No")
    {
        CheckBox1.Checked = true;
        Panel1.Visible = false;
    }

    if (sportHasPositions == "Yes")
    {
        CheckBox1.Checked = false;
        Panel1.Visible = true;
    }

}

protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
    if (CheckBox1.Checked == false)
    {
        String conString = @"Data Source=184.168.47.21;Initial Catalog=RecruitPursuit;Persist Security Info=True;User ID=RecruitPursuit;Password=Recruit20!8";
        SqlConnection con = new SqlConnection(conString);

        //create a command behavior object
        String cmdString = "UPDATE Sport SET SportHasPositions = @SportHasPositions WHERE Sport_Id = @Sport_Id";
        SqlCommand cmd = new SqlCommand(cmdString, con);

        SqlParameter param0 = new SqlParameter();
        param0.ParameterName = "@SportHasPositions";
        param0.Value = "Yes";
        cmd.Parameters.Add(param0);

        SqlParameter param1 = new SqlParameter();
        param1.ParameterName = "@Sport_Id";
        param1.Value = Session["SportID"];
        cmd.Parameters.Add(param1);

        int added = 0;
        try
        {
            con.Open();
            added = cmd.ExecuteNonQuery();
        }

        catch (Exception err)
        {
            // Output.Text = err.Message;
        }

        finally
        {
            con.Close();
        }
        Response.Redirect("Pick Positions.aspx");
    }
        if (CheckBox1.Checked == true)
        {
            String conString = @"Data Source=184.168.47.21;Initial Catalog=RecruitPursuit;Persist Security Info=True;User ID=RecruitPursuit;Password=Recruit20!8";
            SqlConnection con = new SqlConnection(conString);

            //create a command behavior object
            String cmdString = "UPDATE Sport SET SportHasPositions = @SportHasPositions WHERE Sport_Id = @Sport_Id";
            SqlCommand cmd = new SqlCommand(cmdString, con);

            SqlParameter param0 = new SqlParameter();
            param0.ParameterName = "@SportHasPositions";
            param0.Value = "No";
            cmd.Parameters.Add(param0);

            SqlParameter param1 = new SqlParameter();
            param1.ParameterName = "@Sport_Id";
            param1.Value = Session["SportID"];
            cmd.Parameters.Add(param1);

            int added = 0;
            try
            {
                con.Open();
                added = cmd.ExecuteNonQuery();
            }

            catch (Exception err)
            {
                // Output.Text = err.Message;
            }

            finally
            {
                con.Close();
            }


        }

}

Answer 1

问题是asp.net life cycle在Page_Load事件之前运行CheckBox1_CheckedChanged事件。由于在Page_Load中，您设置了复选框，即使用户更改了复选框，Page_Load也会在CheckBox1_CheckedChanged更改数据库之前对其进行更改。要解决此问题，您可以使用Page.IsPostBack 标记，以便Page_Load仅在初始页面加载时设置复选框。

 protected void Page_Load(object sender, EventArgs e)
    {


    if (!Page.IsPostBack) {
        using (SqlConnection dataConnection = new SqlConnection(@"Data Source=184.168.47.21;Initial Catalog=RecruitPursuit;Persist Security Info=True;User ID=RecruitPursuit;Password=Recruit20!8"))
        using (SqlCommand dataCommand =
                new SqlCommand("select SportHasPositions from Sport Where Sport_Id = @Sport_Id", dataConnection))

        {
            SqlParameter param2 = new SqlParameter();
            param2.ParameterName = "@Sport_Id";
            param2.Value = Session["SportID"];
            dataCommand.Parameters.Add(param2);

            dataConnection.Open();
            sportHasPositions = dataCommand.ExecuteScalar().ToString();
        }

        if (sportHasPositions == "No")
        {
            CheckBox1.Checked = true;
            Panel1.Visible = false;
        }

        if (sportHasPositions == "Yes")
        {
            CheckBox1.Checked = false;
            Panel1.Visible = true;
        }
    }
    }

使用复选框更改现有数据库值

1 个答案: