Question

I am trying to add data to a gridview, for example if we select a value from a dropdown, enter a value in a textbox and then click on a button then that data is displayed in a gridview.

I successfully did this but my problem is when I then enter some other text and select other value then the previous record is hidden and a new record is displayed. I want to display both the records which I add.

Should I do this in a loop or something ?

Protected Sub pAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles pAdd.Click

      Dim DT= New DataTable()
        Dim DR As DataRow = dtbl.NewRow()
        DT.Columns.Add(New DataColumn("ID"))
        DT.Columns.Add(New DataColumn("Name"))
        DT.Columns.Add(New DataColumn("Type"))

        DR (0) = TEXT_1.Text
        DR (1) = ddl_name.SelectedItem.Text
        DR (2) = ddl_type.SelectedItem.Text
        DT.Rows.Add(drw1)

        gridv.DataSource = DT
       gridv.DataBind()
    End Sub

Answer 1

 protected void btnAdd_Click(object sender, EventArgs e)
    {

        if (Session["dt"] == null)
        {
            dt = new DataTable();
            dt.Columns.Add("FirstColumn");
            dt.Columns.Add("SecondColumn");
        }
        else
        {
            dt = (DataTable)Session["dt"];
        }

        DataRow row = dt.NewRow();
        row["FirstColumn"] = text_User.Text;
        row["SecondColumn"] = ddl_Use.SelectedIndex;
        dt.Rows.Add(row);
        Session["dt"] = dt;
        gv_grid.DataSource = dt;
        gv_grid.DataBind();
    }

Answer 2

我已经完成了使用这个

Private Sub AddToGrid()
    If ViewState("table") IsNot Nothing Then 
        Dim dtable As DataTable = DirectCast(ViewState("table"), DataTable)
        Dim drow As DataRow = Nothing
        If dtable.Rows.Count > 0 Then
            For i As Integer = 1 To dtable.Rows.Count
               drow = dtable.NewRow()
                drow("ID") = TEXT_1.Text
                drow("Name") = ddl_name.SelectedItem.Text
          drow("Type") = ddl_type.SelectedItem.Text
            Next
            dtable.Rows.Add( drow)
            ViewState("table") =dtable
             gridv.DataSource = dtable
             gridv.DataBind()
        End If
    End If
End Sub

Maintain data of DataTable during postback using session

2 个答案: