//setDefaultStyle
activeSheet.setRowCount(5, GC.Spread.Sheets.SheetArea.viewport);
activeSheet.setColumnCount(5, GC.Spread.Sheets.SheetArea.viewport);

    //Set the default styles.
    var defaultStyle = new GC.Spread.Sheets.Style();
    defaultStyle.backColor = "LemonChiffon";
    defaultStyle.foreColor = "Red";
    defaultStyle.formatter = "0.00";
    defaultStyle.hAlign = GC.Spread.Sheets.HorizontalAlign.center;
    defaultStyle.borderLeft = new GC.Spread.Sheets.LineBorder("Green",GC.Spread.Sheets.LineStyle.medium);
    defaultStyle.borderTop = new GC.Spread.Sheets.LineBorder("Green",GC.Spread.Sheets.LineStyle.medium);
    defaultStyle.borderRight = new GC.Spread.Sheets.LineBorder("Green",GC.Spread.Sheets.LineStyle.medium);
    defaultStyle.borderBottom = new GC.Spread.Sheets.LineBorder("Green",GC.Spread.Sheets.LineStyle.medium);
    activeSheet.setDefaultStyle(defaultStyle, GC.Spread.Sheets.SheetArea.viewport);

    var rowCount = activeSheet.getRowCount();
    var colCount = activeSheet.getColumnCount();
    for(var i = 0; i < rowCount; i++){
        for(var j = 0; j < colCount; j++){
            activeSheet.setValue(i, j, i+j, GC.Spread.Sheets.SheetArea.viewport);
        }
    }