当我第一次使用Excel的时候，就为Excel的图表功能所倾倒，实在强大，并且那些图也挺漂亮了
。后来我尝试着在vb里面调用Excel所支持的vba功能，发现功能的确强大，就是十分繁琐。后来就考虑用vb在Excel外面包一层，写成对象，去掉我们不需要的特性。这样掉用起来就方便多了，所谓一劳永逸 :P。

在这里，我将像大家介绍一个用vb编写的饼图组件，你只需要给它几个简单的参数，就可以生成一副GIF格式的图片给你。调用例子如下：

Dim obj
Set obj = CreateObject("ChinaASPChart.pie")
obj.AddValue "男", 150
obj.AddValue "女", 45
obj.AddValue "不知道", 15
obj.ChartName = "性别比例图"
obj.FileName = "d:\123.gif"
obj.SaveChart


除了在vb里面可以调用，这段代码同样也可以在ASP里面调用。

下面编写我们的组件。

1.New project , 请选择activex dll，在project explorer面板上选择project1,然后在属性面板上修改其name为ChinaASPChart。同样把里面的class modules修改为pie

2.保存该project,将project存为chinaASPchart.vbp,将class1.cls存为pie.cls。

3.菜单project,选择菜单项References,然后请把Microsoft Active Server Pages Ojbect Library、Microsoft Excel 9.0 Object Library、COM+ Services Type Library选上。
注意：在NT4/win98上没有COM+ Service Type Library这个东东，应该选Microsoft Transaction Server Type Library

4.编辑pie.cls,代码如下：


注释：-------------------------------------------------------------------------------
Dim xl
Dim m_chartName
Dim m_chartData()
Dim m_chartType
Dim m_fileName
Public ErrMsg
Public foundErr
Dim iCount

Type m_Value
label As String
value As Double
End Type

Dim tValue As m_Value

Public Property Let ChartType(ChartType)
m_chartType = ChartType
End Property

Public Property Get ChartType()
ChartType = m_chartType
End Property

Public Property Let ChartName(ChartName)
m_chartName = ChartName
End Property

Public Property Get ChartName()
ChartName = m_chartName
End Property

Public Property Let FileName(fname)
m_fileName = fname
End Property
Public Property Get FileName()
FileName = m_fileName
End Property

Public Sub AddValue(label, value)
iCount = iCount + 1
ReDim Preserve m_chartData(iCount)
tValue.label = label
tValue.value = value
m_chartData(iCount) = tValue
End Sub

Public Sub SaveChart()
On Error Resume Next
Dim iSheet
Dim i
Set xl = New Excel.Application
xl.Application.Workbooks.Add
xl.Workbooks(1).Worksheets("sheet1").Activate
If Err.Number <> 0 Then
foundErr = True
ErrMsg = Err.Description
Err.Clear
Else
xl.Workbooks(1).Worksheets("sheet1").Cells("2,1").value = m_chartName
For i = 1 To iCount
xl.Worksheets("Sheet1").Cells(1, i + 1).value = m_chartData(i).label
xl.Worksheets("Sheet1").Cells(2, i + 1).value = m_chartData(i).value
Next
xl.Charts.Add
xl.ActiveChart.ChartType = m_chartType
xl.ActiveChart.SetSourceData xl.Sheets("Sheet1").Range("A1:" & Chr((iCount Mod 26) + Asc("A")) & "2"), 1
xl.ActiveChart.Location 2, "Sheet1"
With xl.ActiveChart
.HasTitle = True
.ChartTitle.Characters.Text = m_chartName
End With
xl.ActiveChart.ApplyDataLabels 2, False, _
True, False
With xl.Selection.Border
.Weight = 2
.LineStyle = 0
End With