[]
Gets or sets the image used as the collapse indicator in the outline column.
This image is displayed for grouped rows when the outline column shows a collapse indicator for the current outline level.
ImageSource CollapseIndicator { get; set; }
Property CollapseIndicator As ImageSource
worksheet.Range["A1:A3"].Value = new object[,] {{"Name"}, {"Node 1"}, {"Node 1.1"}};
worksheet.Range["A3"].IndentLevel = 1;
IOutlineColumn outlineColumn = worksheet.OutlineColumn;
outlineColumn.ColumnIndex = 0;
outlineColumn.CollapseIndicator = new ImageSource(
new MemoryStream(new byte[] {(byte) 137, 80, 78, 71, 13, 10, 26, 10}),
ImageType.PNG);
ImageSource indicator = outlineColumn.CollapseIndicator;