從Array VB.NET獲取DevExpress圖表系列值

Question

我試圖從SQL表中的數據設置DevExpress圖表系列。 除了圖表只采用最后一個系列的最后一個屬性外，一切都很順利。
我的代碼是：

con.Open() 'it opens SQL Connection
For i = 0 To (CheckedListBoxControl1.CheckedItems.Count - 1) 'list from ListBox        
    Lst.Add(CheckedListBoxControl1.CheckedItems(i).ToString) 'Putting Data in Array List
    Dim Strl As String = String.Format("Select * from VPRogressCumulative where fname like '{0}' and lname like  '{1}' order by id, no, CAST('1.' + date AS datetime)", ComboBox1.Text, Lst(i))

    Dim sqlCom As New SqlCommand(Strl)
    sqlCom.Connection = con
    Dim myDA As SqlDataAdapter = New SqlDataAdapter(sqlCom)
    Dim myDataSet As DataSet = New DataSet()
    myDA.Fill(myDataSet, "VPRogressCumulative")
    ChartControl1.DataSource = myDataSet
    ChartControl1.DataAdapter = myDA

    Dim ser As New Series(Lst(i), ViewType.Line)
    ChartControl1.Series.Add(ser)

    ser.ArgumentDataMember = "VPRogressCumulative.Date"
    ser.ValueDataMembers.AddRange(New String() {"VPRogressCumulative.Cumulative"})
Next
con.Close()

我相信我的問題在於：

Dim ser As New Series(Lst(i), ViewType.Line)
ChartControl1.Series.Add(ser)
ser.ArgumentDataMember = "VPRogressCumulative.Date"
ser.ValueDataMembers.AddRange(New String() {"VPRogressCumulative.Cumulative"})

最后兩行給出了同一系列的新屬性，我無法解決這個問題。

Answer 1

你的問題在這里：

ChartControl1.DataSource = myDataSet
ChartControl1.DataAdapter = myDA

在每個循環迭代中，您將創建新的DataSet ，它將覆蓋ChartControl1先前DataSource 。 您必須使用Series.DataSource而不是ChartControl.DataSource 。 您也可以使用DataTable而不是DataSet 。
這是一個例子：

'Your code:
'Dim myDataSet As DataSet = New DataSet()
'myDA.Fill(myDataSet, "VPRogressCumulative")
'ChartControl1.DataSource = myDataSet
'ChartControl1.DataAdapter = myDA

'Replace with this:
Dim myDataTable As DataTable = New DataTable("VPRogressCumulative")
myDA.Fill(myDataTable)

Dim ser As New Series(Lst(i), ViewType.Line)
ChartControl1.Series.Add(ser)

'Your code.
'ser.ArgumentDataMember = "VPRogressCumulative.Date"
'ser.ValueDataMembers.AddRange(New String() {"VPRogressCumulative.Cumulative"})

'Replace with this:
ser.DataSource = myDataTable
ser.ArgumentDataMember = "Date"
ser.ValueDataMembers.AddRange(New String() {"Cumulative"})