การ หาผลรวมของ datagrid ทั้งหมดตามรูปที่แนบมาเลย ครับ

GridView1. FooterRow. Cells[2]. FindControl("Label2")) .Text = myDataSet. Tables[0]. Compute("sum(amount)", ""). ToString()

 public partial class _Default : System.Web.UI.Page
    {
        int i=0;
        double TotalPrice =0.0;


       

        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
          if(e.Row.RowType == DataControlRowType.DataRow)
          {
                i++;
                TotalPrice+=Convert.ToDouble(DataBinder.Eval(e.Row.DataItem,"UnitPrice"));
          }
          else if(e.Row.RowType == DataControlRowType.Footer)
          {
              e.Row.Font.Bold=true;
              e.Row.Cells[0].Text="ราคารวม:";
              e.Row.Cells[2].Text=TotalPrice.ToString("#,###0.00");
          }
        }

        Me.DataGridView1.DataSource = dt
        Me.DataGridView1.Columns.Clear()

        Dim column As DataGridViewTextBoxColumn

        column = New DataGridViewTextBoxColumn()
        column.DataPropertyName = "voucherno"
        column.HeaderText = "เลขที่ใบเบิก"
        column.Width = 85
        Me.DataGridView1.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DataPropertyName = "itemcode"
        column.HeaderText = "รหัสสินค้า"
        column.Width = 85
        Me.DataGridView1.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DefaultCellStyle.Format = "0.00"
        column.DataPropertyName = "mainquantity"
        column.HeaderText = "จำนวนที่เบิก"
        column.Width = 75
        Me.DataGridView1.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DefaultCellStyle.Format = "0.00"
        column.DataPropertyName = "price"
        column.HeaderText = "ราคารวม"
        column.Width = 80
        Me.DataGridView1.Columns.Add(column)

    Private Sub DataGridView1_CellValueChanged(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
    Handles DataGridView1.CellValueChanged
        Dim Sum As Decimal
        If e.ColumnIndex = 2 Then
            For Each dgr As DataGridViewRow In Me.DataGridView1.Rows
                If dgr.Cells(2).Value IsNot DBNull.Value Then
                    Sum += dgr.Cells(2).Value
                End If
            Next
            MessageBox.Show("จำนวนที่รวม = " & Sum)
        ElseIf e.ColumnIndex = 3 Then
            For Each dgr As DataGridViewRow In Me.DataGridView1.Rows
                If dgr.Cells(3).Value IsNot DBNull.Value Then
                    Sum += dgr.Cells(3).Value
                End If
            Next
            MessageBox.Show("จำนวนเงินรวม = " & Sum)
        End If
    End Sub

Sub scap()
        Dim dt As New DataTable
        Dim mycommand As New OdbcCommand
        Dim Adapter As OdbcDataAdapter
        Dim ds As DataSet = New DataSet
        Dim cn As New OdbcConnection("dsn=costmo;uid=sa;pwd=")
        cn.Open()

        Dim cmd = " select voucherno,itemcode,mainquantity,inoutvaluei  " & _
                  "  from inventoryflowdtl " & _
                  " where  mono = '" & voucherno & "'  and approved = '1' and reasonindex = '4' and inout = '1' "

        mycommand.Connection = cn
        mycommand.CommandText = cmd

        Adapter = New OdbcDataAdapter(mycommand)
        'Dim Adapter As SqlDataAdapter
        Adapter.Fill(ds, "table2")
        dt = ds.Tables("table2")
        cn.Close()

        Me.DataGridView3.DataSource = dt
        Me.DataGridView3.Columns.Clear()

        Dim column As DataGridViewTextBoxColumn

        column = New DataGridViewTextBoxColumn()
        column.DefaultCellStyle.BackColor = Color.BlanchedAlmond
        column.DataPropertyName = "voucherno"
        column.HeaderText = "เลขที่ใบเบิก"
        column.Width = 80
        Me.DataGridView3.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DataPropertyName = "itemcode"
        column.HeaderText = "รหัส SCG"
        column.ReadOnly = True
        column.Width = 70
        Me.DataGridView3.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DefaultCellStyle.Format = "0.00"
        column.DataPropertyName = "mainquantity"
        column.HeaderText = "จำนวนที่คืน"
        column.ReadOnly = True
        column.Width = 70
        Me.DataGridView3.Columns.Add(column)

        column = New DataGridViewTextBoxColumn()
        column.DefaultCellStyle.Format = "0.00"
        column.DataPropertyName = "inoutvaluei"
        column.HeaderText = "ราคารวม"
        column.ReadOnly = True
        column.Width = 70
        Me.DataGridView3.Columns.Add(column)

    End Sub

        SumValue(2)
        SumValue(3)

    Private Sub DataGridView1_CellValueChanged(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
   Handles DataGridView1.CellValueChanged
        If e.ColumnIndex = 2 Or e.ColumnIndex = 3 Then
            SumValue(e.ColumnIndex)
        End If
    End Sub

    Private Sub SumValue(ByVal ColumnIndex As Integer)
        Dim Sum As Decimal
        For Each dgr As DataGridViewRow In Me.DataGridView1.Rows
            If dgr.Cells(ColumnIndex).Value IsNot DBNull.Value Then
                Sum += dgr.Cells(ColumnIndex).Value
            End If
        Next
        MessageBox.Show("ผลรวมของ" & Me.DataGridView1.Columns(ColumnIndex).HeaderText & " = " & Sum)
    End Sub