DataGridView实现添加合计行并始终显示在底部

 DataGridView中没有合适的方法来冻结底部的合计行，这里用一种比较简单的方式实现。

1. 数据部分的DataGridView，不带任何滚动框

2.合计部分的DataGridView,带有横向滚动框

3.在画面上添加一个纵向滚动框

实现的主要思路就是用合计行的横向滚动框控制两个DataGridView的横向滚动，右侧的纵向滚动狂控制数据部分的DataGridView，效果看起来就是合计行始终显示。

 

该例实现了合计行的自动计算，取数据的部分是用程序做的DataTable

 

DataGridViewSumRow类

Public Class DataGridViewSumRowClass DataGridViewSumRow

 

    Private dt As DataTable

    Dim dtSum As DataTable

    Private ROW_HEIGHT As Integer = 21 ''行高

 

Private Sub DataGridViewSumRow_Load()

Sub DataGridViewSumRow_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        VScrollBar1.Visible = False

    End Sub

 

    Private Sub Button1_Click()Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

 

        dt = GetData()

        Me.DataGridView1.DataSource = dt

        Me.DataGridView1.RowTemplate.Height = ROW_HEIGHT

 

        GetSumData()

 

        ''行数超过当前页显示时显示纵向滚动条

        If dt.Rows.Count > 13 Then

 

            VScrollBar1.Visible = True

            ''总长度为 （所有行数 - 画面一页显示行数） × 行高

            VScrollBar1.Maximum = (Me.DataGridView1.Rows.Count - Me.DataGridView1.DisplayedRowCount(False)) * ROW_HEIGHT

            VScrollBar1.Minimum = 0

            VScrollBar1.SmallChange = 21

            VScrollBar1.LargeChange = 50

 

        End If

 

    End Sub

 

 

    ''' <summary>

    ''' 合计取得设定

    ''' </summary>

    ''' <remarks></remarks>

 

    Private Sub GetSumData()Sub GetSumData()

        Dim dr As DataRow

 

        dtSum = New DataTable("TEST")

 

        dtSum = dt.Clone

 

        Dim rdm As Random = New Random

        dr = dtSum.NewRow()

        dr(0) = "合计"

 

        For i As Integer = 1 To dt.Columns.Count - 1

            dr(i) = dt.Compute("Sum(" + dt.Columns(i).ColumnName + ")", "true")

        Next

        dtSum.Rows.Add(dr)

 

        Me.DataGridViewSum.DataSource = dtSum

        Me.DataGridViewSum.Rows(0).DefaultCellStyle.BackColor = Color.Brown

        Me.DataGridViewSum.ReadOnly = True

        Me.DataGridViewSum.SelectionMode = DataGridViewSelectionMode.FullRowSelect

 

    End Sub

 

    ''' <summary>

    ''' 数据取得

    ''' </summary>

    ''' <returns></returns>

    ''' <remarks></remarks>

 

    Public Function GetData()Function GetData() As DataTable

 

        Dim dt As DataTable

        Dim dr As DataRow

 

        dt = New DataTable("TEST")

        dt.Columns.Add(New DataColumn("号码", GetType(String)))

        dt.Columns.Add(New DataColumn("数量1", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量2", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量3", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量4", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量5", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量6", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量7", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量8", GetType(Integer)))

        dt.Columns.Add(New DataColumn("数量9", GetType(Integer)))

 

        Dim rdm As Random = New Random

 

        For i As Integer = 10 To 80

            dr = dt.NewRow()

            dr(0) = "00" & i.ToString

            For j As Integer = 1 To 9

                dr(j) = rdm.Next(1000, 5000)

            Next

            dt.Rows.Add(dr)

        Next

 

        Return dt

    End Function

 

    ''' <summary>

    ''' 纵滚动条事件

    ''' </summary>

    ''' <param name="sender"></param>

    ''' <param name="e"></param>

    ''' <remarks></remarks>

    Private Sub VScrollBar1_Scroll()Sub VScrollBar1_Scroll(ByVal sender As Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles VScrollBar1.Scroll

        'Debug.WriteLine(e.NewValue.ToString)

        Me.DataGridView1.FirstDisplayedScrollingRowIndex = e.NewValue  ROW_HEIGHT

 

    End Sub

 

    Private Sub Button2_Click()Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Me.Close()

    End Sub

 

 

    ''' <summary>

    ''' 合计DataGridView的滚动条事件

    ''' </summary>

    ''' <param name="sender"></param>

    ''' <param name="e"></param>

    ''' <remarks></remarks>

 

    Private Sub DataGridViewSum_Scroll()Sub DataGridViewSum_Scroll(ByVal sender As Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles DataGridViewSum.Scroll

        Me.DataGridView1.HorizontalScrollingOffset = e.NewValue

    End Sub

 

    ''' <summary>

    ''' 数据变更后重新合计

    ''' </summary>

    ''' <param name="sender"></param>

    ''' <param name="e"></param>

    ''' <remarks></remarks>

    Private Sub DataGridView1_CellValueChanged()Sub DataGridView1_CellValueChanged(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged

        If e.ColumnIndex <= 0 Then

            Exit Sub

        End If

        ''DetaGridView中数据变化后重新合计

        Me.DataGridViewSum(e.ColumnIndex, 0).Value = dt.Compute("Sum(" + dt.Columns(e.ColumnIndex).ColumnName + ")", "true")

    End Sub

 

 

    ''' <summary>

    ''' 响应鼠标滚轴事件

    ''' </summary>

    ''' <param name="sender"></param>

    ''' <param name="e"></param>

    ''' <remarks></remarks>

    Private Sub DataGridViewSumRow_MouseWheel()Sub DataGridViewSumRow_MouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseWheel

 

        If VScrollBar1.Visible = False Then

            Exit Sub

        End If

 

        If VScrollBar1.Value - ROW_HEIGHT < 0 And e.Delta > 0 Then

            VScrollBar1.Value = VScrollBar1.Minimum

            Exit Sub

        End If

 

        If VScrollBar1.Value + ROW_HEIGHT > VScrollBar1.Maximum And e.Delta < 0 Then

            VScrollBar1.Value = VScrollBar1.Maximum

            Exit Sub

        End If

 

        Try

            VScrollBar1.Value -= CInt(e.Delta / Math.Abs(e.Delta) * ROW_HEIGHT)

        Catch ex As Exception

            Debug.WriteLine("###########################")

            Debug.WriteLine("VScrollBar1.Value = " & VScrollBar1.Value)

            Debug.WriteLine("e.Delta = " & e.Delta)

            Debug.WriteLine("###########################")

        End Try

        Me.DataGridView1.FirstDisplayedScrollingRowIndex = VScrollBar1.Value  ROW_HEIGHT

 

    End Sub

End Class