很简单,把_替换成vbcrlf即可,如
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
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
Series.Length = 4
For i As Integer = 0 To 3
Series.X(i) = i '指定水平坐标
Series.Y(i) = 100
Chart.AxisX.SetValueLabel(i, "a" & vbcrlf & "b") '指定字符表示
Next
Chart.AxisX.AnnoWithLabels = True '启用字符标示