从C＃将系列添加到Excel图表（气泡图）

Question

I have written a table in excel from c#. i want to plot a bubble chart from this data using c#. With the code given below I have managed to add just one series for TCB_A. Column B is y value and Column C is bubble size for series TCB_A. How can I add the other 3 series (for TCB_B, TCB_C and TCB_D) as well? any help will be greatly appreciated.

 Excel.Shape chart_shape 
=worksheet.Shapes.AddChart(Excel.XlChartType.xlBubble, 250, 10, 440, 150);
Excel.Chart chart = chart_shape.Chart;
Excel.SeriesCollection series = 
(Excel.SeriesCollection)chart.SeriesCollection();
Excel.Series series1 = series.NewSeries();
Excel.Range x_range = worksheet.get_Range("A2:A7");
Excel.Range range_a = worksheet.get_Range("B2", "C7");
//tcb_a
Excel.Series a = (Excel.Series)chart.SeriesCollection(1);
chart.SetSourceData(range_a);
a.XValues = x_range;
a.Name = "TCB_A";

if I also put the code given below then it overwrites my existing series with new data and i get only 1 series as a result.

Excel.Range range_b = worksheet.get_Range("D2", "E7");
Excel.Series b = (Excel.Series)chart.SeriesCollection(1);  
chart.SetSourceData(range_b);
b.XValues = x_range;
b.Name = "TCB_B";

Answer 1

The following code auto-generated the 4 series:

 Excel.Range range_a = worksheet.get_Range("A2", "I7");

The first cell A1, if selected in chart data-selection range, tends to create unusual series. Or, if u wish to keep the cell A1 in the selection range, just set its value blank.