有下面一段代码

Dim g As New GroupTableBuilder("统计表1", DataTables("采购主表"))
g.Groups.AddDef("订货日期", DateGroupEnum.Year, "年")
g.Groups.AddDef("厂家名称")
g.Totals.AddDef("采购含税合计")
g.SubTotal = True
g.Build()

想做几个按钮， 本年采购额， 上一年采购额， 下一年采购额， 代码如何写呢？

设置条件不就行？年加减1

http://www.foxtable.com/help/topics/2720.htm

Dim y As Integer = Date.Today.Year
Dim dt1 As New Date(y, 1, 1)
Dim dt2 As New Date(y, 12, 31)
Dim g As New GroupTableBuilder("统计表1", DataTables("采购主表")，"订货日期 >= #" & dt1 & "# And 订货日期 <= #" & dt2 & "#" )
g.Groups.AddDef("订货日期", DateGroupEnum.Year, "年")
g.Groups.AddDef("厂家名称")
g.Totals.AddDef("采购含税合计")
g.SubTotal = True
g.Build()

Tables ("统计汇总_Table1" ). DataSource = g.BuildDataSource()

Dim y As Integer = Date.Today.Year
Dim dt1 As New Date(y, 1, 1)
Dim dt2 As New Date(y, 12, 31)
Dim g As New GroupTableBuilder("统计表1", DataTables("采购主表"),"订货日期 >= #" & dt1 & "# And 订货日期 <= #" & dt2 & "#" )
g.Groups.AddDef("订货日期", DateGroupEnum.Year, "年")
g.Groups.AddDef("厂家名称")
g.Totals.AddDef("采购含税合计")
g.SubTotal = True
g.Build()
Tables ("统计汇总_Table1" ). DataSource = g.BuildDataSource()

Dim Chart As WinForm.Chart \'定义一个图表变量
Dim Series As WinForm.ChartSeries \'定义一个图系变量
Dim t As Table = Tables("统计表1") \'定义一个变量t引用数据表
Chart= e.Form.Controls("Chart1") \' 引用窗口中的图表
Chart.SeriesList.Clear() \'清除图表原来的图系
Series = Chart.SeriesList.Add() \'增加一个图系
Chart.ChartType = ChartTypeEnum.Bar
Series.Length = t.Rows.Count \'图系的数据点数等于表的行数
For i As Integer = 0 To t.Rows.Count - 1 \'指定每个数据点的位置
    Series.X(i) = t.Rows(i)("厂家名称") \'指定水平坐标
    Series.Y(i) = t.Rows(i)("采购含税合计") \'指定垂直坐标
    Series.DataLabelText = "{#YVAL}"
Next

这段代码哪里有问题呢？

Dim y As Integer = Date.Today.Year
Dim dt1 As New Date(y, 1, 1)
Dim dt2 As New Date(y, 12, 31)
Dim g As New GroupTableBuilder("统计表1", DataTables("采购主表"),"订货日期 >= #" & dt1 & "# And 订货日期 <= #" & dt2 & "#" )
g.Groups.AddDef("订货日期", DateGroupEnum.Year, "年")
g.Groups.AddDef("厂家名称")
g.Totals.AddDef("采购含税合计")
g.SubTotal = True
Tables ("统计汇总_Table1" ). DataSource = g.BuildDataSource()

Dim Chart As WinForm.Chart \'定义一个图表变量
Dim Series As WinForm.ChartSeries \'定义一个图系变量
Dim t As Table = Tables ("统计汇总_Table1" )
Chart= e.Form.Controls("Chart1") \' 引用窗口中的图表
Chart.SeriesList.Clear() \'清除图表原来的图系
Series = Chart.SeriesList.Add() \'增加一个图系
Chart.ChartType = ChartTypeEnum.Bar
Series.Length = t.Rows.Count \'图系的数据点数等于表的行数
For i As Integer = 0 To t.Rows.Count - 1 \'指定每个数据点的位置
    Series.X(i) = t.Rows(i)("厂家名称") \'指定水平坐标
    Series.Y(i) = t.Rows(i)("采购含税合计") \'指定垂直坐标
    Series.DataLabelText = "{#YVAL}"
Next

看完