Arrowheads SpreadsheetGear API Sample

// Create a new workbook and some local variables.
SpreadsheetGear.IWorkbook workbook = SpreadsheetGear.Factory.GetWorkbook();
SpreadsheetGear.IWorksheet worksheet = workbook.ActiveWorksheet;
SpreadsheetGear.IWorksheetWindowInfo windowInfo = worksheet.WindowInfo;

// Create an IEnumerable out of the various ArrowheadStyle enum options.  Note that
// "Mixed" and "None" are excluded since these aren't applicable to this sample.
var arrowheadStyles = Enum.GetValues(typeof(SpreadsheetGear.Shapes.ArrowheadStyle))
    .OfType<SpreadsheetGear.Shapes.ArrowheadStyle>()
    .Where(a => a != SpreadsheetGear.Shapes.ArrowheadStyle.Mixed &&
        a != SpreadsheetGear.Shapes.ArrowheadStyle.None)
    .ToList();

// Similarly, create an IEnumerable of ArrowheadLength options, excluding "Mixed".
var arrowheadLengths = Enum.GetValues(typeof(SpreadsheetGear.Shapes.ArrowheadLength))
    .OfType<SpreadsheetGear.Shapes.ArrowheadLength>()
    .Where(a => a != SpreadsheetGear.Shapes.ArrowheadLength.Mixed)
    .ToList();

// Similarly, create an IEnumerable of ArrowheadWidth options, excluding "Mixed".
var arrowheadWidths = Enum.GetValues(typeof(SpreadsheetGear.Shapes.ArrowheadWidth))
    .OfType<SpreadsheetGear.Shapes.ArrowheadWidth>()
    .Where(a => a != SpreadsheetGear.Shapes.ArrowheadWidth.Mixed)
    .ToList();

// Expand cell size so a line and its arrowheads better fits.
worksheet.Cells.RowHeight = 38;
worksheet.Cells.ColumnWidth = 26;

// Will use these two IRanges to "navigate" around the worksheet.  Since one IRange 
// represents an entire row and the other an entire column, we can take the 
// intersection of the two with IRange.Intersect(...) to isolate a specific cell
// and add a line into it.
SpreadsheetGear.IRange currentRow = worksheet.Cells["2:2"];
SpreadsheetGear.IRange currentColumn = worksheet.Cells["B:B"];
            
// To demonstrate including or omitting an End Arrowhead, we'll setup this counter
// to only add an End Arrowhead on every other line added.
int counter = 0;
            
// Loop through various Arrowhead Styles--one style for each column across the sheet.
foreach (SpreadsheetGear.Shapes.ArrowheadStyle arrowheadStyle in arrowheadStyles)
{
    // Take intersection of "currentColumn" and Row 1:1 to isolate the row header
    // cell and set its value to the Arrowhead Style.
    SpreadsheetGear.IRange rowHeaderCell = currentColumn.Intersect(worksheet.Cells["1:1"]);
    rowHeaderCell.Value = arrowheadStyle.ToString();

    // Loop through each Arrowhead Width
    foreach (SpreadsheetGear.Shapes.ArrowheadWidth arrowheadWidth in arrowheadWidths)
    {
        // Also loop through each Arrowhead Length
        foreach (SpreadsheetGear.Shapes.ArrowheadLength arrowheadLength in arrowheadLengths)
        {
            // Take intersection of "currentRow" and Column A to isolate the column 
            // header cell and set its value to the ArrowheadWidth and ArrowheadLength
            // enum values
            // being used.
            SpreadsheetGear.IRange headerCol = 
                currentRow.Intersect(worksheet.Cells["A:A"]);
            headerCol.Value = $"Arrowhead Width: {arrowheadWidth}\r\n" +
                $"Arrowhead Height: {arrowheadLength}";

            // Take intersection of current row and column to isolate the cell that we
            // will add the line to.
            SpreadsheetGear.IRange currentCell = currentRow.Intersect(currentColumn);

            // Calculate the position of the line.
            double xStart = windowInfo.ColumnToPoints(currentCell.Column) + 20;
            double yStart = windowInfo.RowToPoints(currentCell.Row) + 15;
            double xEnd = windowInfo.ColumnToPoints(currentCell.Column + 1) - 20;
            double yEnd = windowInfo.RowToPoints(currentCell.Row + 1) - 15;

            // Add the line and get its ILineFormat.
            SpreadsheetGear.Shapes.IShape lineShape = worksheet.Shapes.AddLine(xStart, 
                yStart, xEnd, yEnd);
            SpreadsheetGear.Shapes.ILineFormat lineFormat = lineShape.Line;

            // Set the Arrowhead Style, Width and Length values.
            lineFormat.BeginArrowheadStyle = arrowheadStyle;
            lineFormat.BeginArrowheadWidth = arrowheadWidth;
            lineFormat.BeginArrowheadLength = arrowheadLength;

            // For every other line added, will do the same for the End Arrowhead.
            if (counter % 2 == 0)
            {
                lineFormat.EndArrowheadStyle = arrowheadStyle;
                lineFormat.EndArrowheadWidth = arrowheadWidth;
                lineFormat.EndArrowheadLength = arrowheadLength;
            }

            // Set the weight of the line to 5 Points.
            lineFormat.Weight = 5;

            // Choose a random Theme Color to apply to this line.
            lineFormat.ForeColor.ThemeColor = PickRandomThemeColor();

            // Move the currentRow down one row and advance the End Arrowhead counter.
            currentRow = currentRow.Offset(1, 0);
            counter++;
        }
    }
    // Move the currentColumn right one column and reset the currentRow back to 2:2.
    currentColumn = currentColumn.Offset(0, 1);
    currentRow = worksheet.Cells["2:2"];
}

// Setup some formatting of the header content.
worksheet.Cells["1:1"].HorizontalAlignment = SpreadsheetGear.HAlign.Center;
worksheet.Cells["1:1,A:A"].VerticalAlignment = SpreadsheetGear.VAlign.Center;
worksheet.Cells["1:1,A:A"].Font.Bold = true;

private static Random _rand = new Random();
private static SpreadsheetGear.Themes.ColorSchemeIndex PickRandomThemeColor()
{
    // Construct a List from the ColorSchemeIndex enum that consists of the 6 "Accent"
    // colors as well as Text1 (black).
    var colors = Enum.GetValues(typeof(SpreadsheetGear.Themes.ColorSchemeIndex))
        .OfType<SpreadsheetGear.Themes.ColorSchemeIndex>()
        .Where(c => 
            c.ToString().Contains("Accent") || 
            c == SpreadsheetGear.Themes.ColorSchemeIndex.Text1)
        .ToList();

    // Return random color from list.
    return colors[_rand.Next(colors.Count())];
}