C# Bar Chart SpreadsheetGear API Sample

Excel-Compatible Samples for .NET

Description

Creating Excel-compatible Bar Charts is trivial to do with SpreadsheetGear. At its most basic level you call IShapes.AddChart(...) and then set the returned chart object to use a ChartType.BarStacked chart type (or one of the other bar-based chart types).

The below sample demonstrates this process and performs a few other tasks to properly setup the chart:

Opens an Excel workbook (ChartData.xlsx) pre-populated with chart source data located in the Defined Name "RegionalSales" which points to the range G2:K6.
Charts are positioned on the worksheet relative to the top-left edge of the worksheet (in Points); however, you might want to position the bar chart based on row / column indexes. SpreadsheetGear can take care of this conversion by using the IWorksheetWindowInfo.ColumnToPoints(double columnIndex) and RowToPoints(double rowIndex) methods.
Adds the chart at the specified worksheet location by calling IShapes.AddChart(double top, double left, double width, double height) and setting the source data for the chart by calling IChart.SetSourceData(IRange source, RowCol rowCol).
Sets the chart's type (IChart.ChartType) to ChartType.BarStacked. Other bar-based chart types are available, such as ChartType.BarStacked100, ChartType.BarClustered and others.
Additional chart options are configured, including:
- Setting the "gap width" via IChartGroup.GapWidth, i.e., the distance between bars as a percentage of the bar width.
- Adding a chart title by setting IChart.HasTitle to true, then setting the title text and other chart title options under the IChart.ChartTitle property.
- Accessing the "value" axis (X-axis) via the IChart.Axes[...] collection to apply a dashed line for the major gridlines.

Sample C# Source Code

// Open workbook with some data for the chart and get a reference to the active 
// sheet and its cells.
SpreadsheetGear.IWorkbook workbook = 
    SpreadsheetGear.Factory.GetWorkbook("ChartData.xlsx");
SpreadsheetGear.IWorksheet worksheet = workbook.ActiveWorksheet;
SpreadsheetGear.IRange cells = worksheet.Cells;

// Get a reference to the worksheet window info and shapes collection.
SpreadsheetGear.IWorksheetWindowInfo windowInfo = worksheet.WindowInfo;
SpreadsheetGear.Shapes.IShapes shapes = worksheet.Shapes;

// Add a chart to the worksheet's shape collection.
// NOTE: Calculate the coordinates of the chart by converting row and column
//       coordinates to points.  Use fractional row and column values to get 
//       coordinates anywhere in between row and column boundaries.
double left = windowInfo.ColumnToPoints(0.15);
double top = windowInfo.RowToPoints(0.5);
double right = windowInfo.ColumnToPoints(5.85);
double bottom = windowInfo.RowToPoints(13.5);
SpreadsheetGear.Charts.IChart chart =
    shapes.AddChart(left, top, right - left, bottom - top).Chart;

// Get the source data range from an existing defined name.
SpreadsheetGear.IRange source = workbook.Names["RegionalSales"].RefersToRange;

// Set the chart's source data range, plotting series in columns.
chart.SetSourceData(source, SpreadsheetGear.Charts.RowCol.Columns);

// Set the chart type to a stacked bar.
chart.ChartType = SpreadsheetGear.Charts.ChartType.BarStacked;

// Set the distance between bars as a percentage of the bar width.
chart.ChartGroups[0].GapWidth = 50;

// Add a chart title and change the font size.
chart.HasTitle = true;
chart.ChartTitle.Text = "Combined Sales by Quarter";
chart.ChartTitle.Font.Size = 12;

// Get a reference to the value axis and set the gridline dash style.
SpreadsheetGear.Charts.IAxis valueAxis =
    chart.Axes[SpreadsheetGear.Charts.AxisType.Value];
valueAxis.MajorGridlines.Format.Line.DashStyle =
    SpreadsheetGear.Shapes.LineDashStyle.Dash;