無法在MS圖表控件中動態更改SeriesChartType

Question

我正在使用MS Chart控件（版本3.5.0）。 我通過使用設計器（拖放）添加了它。 我從“屬性”->“系列”->“集合”中刪除了默認的“ Series1”，以便該圖表不包含任何數據。

我在運行時基於罐裝查詢將數據添加到SQLite DB。 像這樣：

Dim SQL As String = "SELECT * FROM ageLength ORDER BY month"
Dim cmd As New SQLiteCommand(SQL)
Dim SqLiteConnection1 As SQLiteConnection = New SQLiteConnection()
SqLiteConnection1.ConnectionString = "Data Source=" & My.Application.Info.DirectoryPath & "\Data\UserData.db3;"
cmd.Connection = SqLiteConnection1
Dim da As New SQLiteDataAdapter(cmd)
Dim ds As New DataSet()
da.Fill(ds, "ageLength")

Dim Series1 As Series = New Series()
Dim Series2 As Series = New Series()
Series1.Name = "Pcnt2nd"
Series1.ChartType = SeriesChartType.Spline
Series2.Name = "Pcnt98th"
Series2.ChartType = SeriesChartType.Spline
Chart1.Series.Add("Pcnt2nd")
Chart1.Series.Add("Pcnt98th")

Chart1.Series("Pcnt2nd").XValueMember = "month"
Chart1.Series("Pcnt2nd").YValueMembers = "Pcnt2nd"
Chart1.Series("Pcnt98th").XValueMember = "month"
Chart1.Series("Pcnt98th").YValueMembers = "Pcnt98th"
Chart1.DataSource = ds.Tables(0)

數據顯示在圖表上，但是它是條形圖。 我將其設置為對兩個系列都使用樣條線類型。 我不確定我錯過了什么。 任何輸入，不勝感激。

Answer 1

經過一番混亂之后，我找到了解決方案：我刪除了這兩行：

Series1.ChartType = SeriesChartType.Spline
Series2.ChartType = SeriesChartType.Spline

然后添加以下兩行：

Chart1.Series("Pcnt2nd").ChartType = DataVisualization.Charting.SeriesChartType.Line
Chart1.Series("Pcnt98th").ChartType = DataVisualization.Charting.SeriesChartType.Line

不知道為什么會這樣...但是在那里。