Question

我试图从下拉列表中获取所选值，该列表位于webform的面板中以执行某些计算。我已经创建了一些动态生成的下拉列表，现在我必须从这些下拉列表中检索所选值以计算总数，然后确保它不超过100.总数应该在文本框中显示。你可以帮帮我吗？

protected void btn_AddObjectives_Click(object sender, EventArgs e)
{
    int rowCount = 0;

    //initialize a session.
    rowCount = Convert.ToInt32(Session["clicks"]);

    rowCount++;

    //In each button click save the numbers into the session.
    Session["clicks"] = rowCount;


    //Create the textboxes and labels each time the button is clicked.
    for (int i = 0; i < rowCount; i++)
    {

        TextBox TxtBoxO = new TextBox();
        TxtBoxO.TextMode = TextBoxMode.MultiLine;
        DropDownList DDLW = new DropDownList();
        DropDownList DDLA = new DropDownList();

        Label lblO = new Label();
        Label lblW = new Label();
        Label lblA = new Label();

        TxtBoxO.ID = "TextBoxU" + i.ToString();
        DDLW.ID = "DDLW" + i.ToString();
        DDLA.ID = "DDLA" + i.ToString();


        TxtBoxO.Width = 325;
        DDLW.Height = 25;
        DDLA.Height = 25;


        DDLA.ID = "ddl_Weight";
        DDLA.Items.Add("Select");
        DDLA.Items.Add("5");
        DDLA.Items.Add("10");
        DDLA.Items.Add("15");
        DDLA.Items.Add("20");
        DDLA.Items.Add("25");
        DDLA.Items.Add("30");
        DDLA.Items.Add("35");
        DDLA.Items.Add("40");
        DDLA.Items.Add("45");
        DDLA.Items.Add("50");
        DDLA.Items.Add("55");
        DDLA.Items.Add("60");
        DDLA.Items.Add("65");
        DDLA.Items.Add("70");
        DDLA.Items.Add("75");
        DDLA.Items.Add("80");
        DDLA.Items.Add("85");
        DDLA.Items.Add("90");
        DDLA.Items.Add("95");
        DDLA.Items.Add("100");

        DDLW.ID = "ddl_Achieved";
        DDLW.Items.Add("Select");
        DDLW.Items.Add("5");
        DDLW.Items.Add("10");
        DDLW.Items.Add("15");
        DDLW.Items.Add("20");
        DDLW.Items.Add("25");
        DDLW.Items.Add("30");
        DDLW.Items.Add("35");
        DDLW.Items.Add("40");
        DDLW.Items.Add("45");
        DDLW.Items.Add("50");
        DDLW.Items.Add("55");
        DDLW.Items.Add("60");
        DDLW.Items.Add("65");
        DDLW.Items.Add("70");
        DDLW.Items.Add("75");
        DDLW.Items.Add("80");
        DDLW.Items.Add("85");
        DDLW.Items.Add("90");
        DDLW.Items.Add("95");
        DDLW.Items.Add("100");

        lblO.ID = "LabelO" + i.ToString();
        lblW.Text = "LabelW" + i.ToString();
        lblA.ID = "LabelA" + i.ToString();

        lblO.Text = "Objective " + " " + (i + 1).ToString() + " : ";
        lblW.Text = " Weightage" + " " + (i + 1).ToString() + " : ";
        lblA.Text = " Achieved " + " " + (i + 1).ToString() + " : ";


        //Add the labels and textboxes to the Panel.
        Panel1.Controls.Add(lblO);
        Panel1.Controls.Add(TxtBoxO);

        Panel1.Controls.Add(lblW);
        Panel1.Controls.Add(DDLW);

        Panel1.Controls.Add(lblA);
        Panel1.Controls.Add(DDLA);
    }
}

Answer 1

将事件处理程序附加到for循环中的所有下拉列表中，如此

 DDLA.AutoPostBack = true;
 DDLA.SelectedIndexChanged += DDLA_SelectedIndexChanged;

DDLW.AutoPostBack = true;
DDLW.SelectedIndexChanged += DDLW_SelectedIndexChanged;

然后

事件中的

    protected void DDLA_SelectedIndexChanged(object sender, EventArgs e)
            {
               // typecast sender as dropdown list and logic to calculate selected value
            }
    protected void DDLW_SelectedIndexChanged(object sender, EventArgs e)
            {
               // typecast sender as dropdown list and logic to calculate selected value
            }

希望这有帮助

如何从面板中的下拉列表中获取选定值并进行计算？

1 个答案: