javascript - 为什么单击我的按钮时没有出现进度条

Question

我做了一些计算，这个过程需要时间，所以我使用 RadProgressArea 。我希望当我单击进行计算的按钮时出现进度条，但进度条根本不出现！

 <telerik:RadProgressManager ID="Radprogressmanager1" runat="server" />

    <script type="text/javascript">
        //<![CDATA[
        function onClientProgressBarUpdating(progressArea, args) {
            progressArea.updateVerticalProgressBar(args.get_progressBarElement(), args.get_progressValue());
            args.set_cancel(true);
        }
        //]]>
    </script>

---

<tr>
            <td colspan="2">
                &nbsp;
                <telerik:RadButton ID="btn_cal_real" runat="server" OnClick="btn_cal_real_Click"
                    Text="Calc">
                    <Icon PrimaryIconCssClass="rbConfig" PrimaryIconLeft="4" PrimaryIconTop="4" />
                </telerik:RadButton>
            </td>
        </tr>
    </table>
    <br />
    <div class="qsf-demo-canvas">
        <telerik:RadProgressArea runat="server" ID="RadProgressArea1" OnClientProgressBarUpdating="onClientProgressBarUpdating">
            <ProgressTemplate>
                <div class="rpaInner">
                    <div class="rpaHeader">
                        <strong>Total Progress</strong>
                    </div>
                    <div class="rpaBody">
                        <dl>
                            <dt class="rpaStatFirst">Total Progress Percent</dt>
                            <dd class="rpaStatFirst">
                                <span runat="server" id="PrimaryPercent"></span>%</dd>
                            <dt>Total Progress:</dt>
                            <dd>
                                <span runat="server" id="PrimaryValue"></span>
                            </dd>
                            <dt>Time Elapsed:</dt>
                            <dd>
                                <span runat="server" id="TimeElapsed"></span>
                            </dd>
                            <dt>Time Estimated:</dt>
                            <dd>
                                <span runat="server" id="TimeEstimated"></span>
                            </dd>
                            <dt>Transfer Speed:</dt>
                            <dd>
                                <span runat="server" id="Speed"></span>
                            </dd>
                        </dl>
                    </div>
                </div>
            </ProgressTemplate>
        </telerik:RadProgressArea>
    </div>