[转载]DataGridView实现添加合计行并始终显示在底部

(原创文章，转载请注明来源：/article/9380716.html)

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

效果如下