public class FormatController : Controller
{
    // GET: Format
    public ActionResult FormatIndex()
    {
        return View();
    }
}

<script src="http://cdnjs.cloudflare.com/ajax/libs/jszip/2.5.0/jszip.min.js">
</script>
<script type="text/javascript">
    function setBold() {
        var flex = wijmo.Control.getControl("#fSheet");
        flex.applyCellsStyle({ fontWeight: 'bold' });
    }
    function changeFont() {
        var flex = wijmo.Control.getControl("#fSheet");
        flex.applyCellsStyle({ fontFamily: 'Unicode' });
    }
    function changeFontSize() {
        var flex = wijmo.Control.getControl("#fSheet");
        flex.applyCellsStyle({ fontSize: '18px' });
    }
    function setColor() {
        var flex = wijmo.Control.getControl("#fSheet");
        flex.applyCellsStyle({ backgroundColor: '#CCCCFF' });
    }
    function align() {
        var flex = wijmo.Control.getControl("#fSheet");
        flex.applyCellsStyle({ textAlign: 'Right' });
    }
</script>

<div>
<input id="font" type="button" onclick="changeFont()" value="フォントを変更" />
<input id="bold" type="button" onclick="setBold()" value="大胆" />
<input id="cellColor" type="button" onclick="setColor()" value="色" />
<input id="fontSize" type="button" onclick="changeFontSize()" value="フォントサイズ" />
<input id="textAlign" type="button" onclick="align()" value="中央に排す" />
<br />
    <c1-flex-sheet class="flexSheet" id="fSheet" Height="500" 
Width="1500" file-path="~/Content/FlexSheet/QuarterlyData.xlsx">
    </c1-flex-sheet>
</div>