值不能為空。 參數名稱：控制

Question

        <cc1:ConfirmButtonExtender DisplayModalPopupID="ModalPopupExtender4" ID="ConfirmButtonExtender4"
            runat="server" TargetControlID="lnkremoveloc" Enabled="False" OnClientCancel="RemoveLocations">
        </cc1:ConfirmButtonExtender>
        <cc1:ModalPopupExtender ID="ModalPopupExtender4" OkControlID="btnDisable" CancelControlID="btnCancel"
            BackgroundCssClass="modalBackground" PopupControlID="pnlRemove" TargetControlID="lnkremoveloc"
            runat="server">
        </cc1:ModalPopupExtender>
        <asp:Panel CssClass="modalPopup" ID="PnlRemove" runat="server">
            <!-- Common Popup Control Begin -->
            <table class="tblCommonPopup" width="400" cellpadding="0" cellspacing="0">
                <tr>
                    <td class="topLeft">
                    </td>
                    <td class="topMiddle">
                    </td>
                    <td class= "topRight">
                    </td>
                </tr>
                <tr>
                    <td colspan="5" class="middle" align="center">
                        <!-- Content Area Begin -->
                        <table>
                            <tr>
                                <td colspan="1" style="padding-top: 10px;" title="Select">


                                </td>
                                <td colspan="4" style="padding-top: 10px;" title="Location Name">

                                </td>
                            </tr>
                            <tr>
                                <td align="center" colspan="5">
                                    <input id="btnDisable" type="button" value="Disable" class="popupButton" />
                                    <input id="Cancel" type="button" value="Cancel" class="popupButton" />
                                </td>
                            </tr>
                        </table>
                        <!-- Content Area Ends -->
                    </td>
                </tr>
                <tr>
                    <td class="bottomLeft">
                    </td>
                    <td class="bottomMiddle">
                    </td>
                    <td class="bottomRight">
                    </td>
                </tr>
            </table>
            <!-- Common Popup Control End -->
        </asp:Panel>

Answer 1

該錯誤意味着存在一個Dependency屬性，該屬性的值為null，不允許其中一個值。 不幸的是，您僅粘貼了部分代碼，因此我無法知道它是哪個屬性-請粘貼您​​控件的完整代碼。