Error #1009: while loading datagrid in to appl

Question

Below exeption showing while trying to load datagrid in to my application..
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at mx.controls::DataGrid/createItemEditor()[E:\dev\4.0.0\frameworks\projects\framework\src\m x\controls\DataGrid.as:4325]
at mx.controls::DataGrid/itemEditorItemEditBeginHandler()[E:\dev\4.0.0\frameworks\projects\f ramework\src\mx\controls\DataGrid.as:5237]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\co re\UIComponent.as:12266]
at mx.controls::DataGrid/commitEditedItemPosition()[E:\dev\4.0.0\frameworks\projects\framewo rk\src\mx\controls\DataGrid.as:4093]
at mx.controls::DataGrid/updateDisplayList()[E:\dev\4.0.0\frameworks\projects\framework\src\ mx\controls\DataGrid.as:1804]
at mx.controls.listClasses::ListBase/validateDisplayList()[E:\dev\4.0.0\frameworks\projects\ framework\src\mx\controls\listClasses\ListBase.as:3962]
at mx.managers::LayoutManager/validateClient()[E:\dev\4.0.0\frameworks\projects\framework\sr c\mx\managers\LayoutManager.as:932]
at mx.core::UIComponent/validateNow()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\core \UIComponent.as:7631]
at mx.managers::PopUpManagerImpl/centerPopUp()[E:\dev\4.0.0\frameworks\projects\framework\sr c\mx\managers\PopUpManagerImpl.as:485]
at mx.managers::PopUpManager$/centerPopUp()[E:\dev\4.0.0\frameworks\projects\framework\src\m x\managers\PopUpManager.as:213]

Answer 1

this is my code for datagrid... please check..
<commoncomponents:ListDatagrid id="reportGroupDetailsListDG"
                                               dataProvider="{ReportGroupDetailsModelLocator.getInstance().reportGroupVO.reportDefinitio nList}"
                                               width="100%"
                                               keyDown="{reportGroupDetailsHelper.handleDataGridKeyDown(event,
                                                         Constants.VIEW_REPORT_GROUP,modelLocator.reportGroupVO.reportDefinitionList,ReportGroupDe tailComponent,'EX', -1);}"
                                               keyUp="{reportGroupDetailsHelper.handleHotKeys(modelLocator.reportGroupVO.reportDefinitio nList,event,
                                                                                 EventConstants.REPORT_GROUP_EVENT,Constants.LIST_REPORT_GROUP_DETAILS,
                                                                                     reportGroupDetailsHelper.displayError, Constants.PAGE_REPORT_GROUP, -1);}"
                                               >
                    <commoncomponents:columns>
                        <mx:DataGridColumn width="20"
                                           headerText=""
                                           dataField="userAction"
                                           rendererIsEditor="true"
                                           visible="{(reportGroupDetailsHelperVO.state == Constants.STATE_EDIT ||
                                           reportGroupDetailsHelperVO.state == Constants.STATE_ADD_NEW) ? true : false}">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <commoncomponents:BDCUserActionTextInput height="10"
                                                  width="10"
                                                  fontFamily="Arial"
                                                  fontWeight="bold"
                                                  textAlign="center"
                                                  maxChars="1"
                                                  restrict="XE"
                                                  text="{data.userAction}"
                                                  includeInLayout="{parentDocument.reportGroupDetailsHelperVO.state == Constants.STATE_EDIT ? true : false}">
                                        <commoncomponents:keyDown>
                                                <![CDATA[
                                                    ListItemVO(ReportGroupDetailsModelLocator.getInstance().reportGroupVO.reportDefinitionLis t.getItemAt
                                                        (event.currentTarget.document.reportGroupDetailsListDG.selectedIndex)).userAction
                                                    = event.target.text;
                                                  ]]>
                                        </commoncomponents:keyDown>
                                    <mx:Script>
                                        <![CDATA[
                                        import com.bnymellon.bds.bdc.ui.model.reportgroup.ReportGroupDetailsModelLocator;;
                                        import com.bnymellon.bds.bdc.ui.vos.ListItemVO;
                                        import com.bnymellon.bds.bdc.ui.utility.Constants;
                                        ]]>
                                    </mx:Script>
                                    </commoncomponents:BDCUserActionTextInput>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                        <mx:DataGridColumn editable="false"
                                           headerText="Report Name"
                                           dataField="command" width="120">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <mx:HBox paddingLeft="5">
                                        <mx:Text styleName="normalText"
                                                 text="{data.command}"/>
                                    </mx:HBox>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                        <mx:DataGridColumn editable="false"
                                           headerText="Access Level Id"
                                           dataField="accountScopeID" width="150">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <mx:HBox paddingLeft="5">
                                        <mx:Text styleName="normalText"
                                                 text="{data.reportGroupScopeId}"/>
                                    </mx:HBox>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                        <mx:DataGridColumn editable="false"
                                           headerText="Security ID"
                                           dataField="security" width="140">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <mx:HBox paddingLeft="5">
                                        <mx:Text styleName="normalText"
                                                 text="{data.security}"/>
                                    </mx:HBox>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                        <mx:DataGridColumn editable="false"
                                           headerText="Qualifier"
                                           dataField="reportParam">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <mx:HBox paddingLeft="5">
                                        <mx:Text styleName="normalText" width="100%"
                                                 text="{data.parameter}"/>
                                    </mx:HBox>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                        <mx:DataGridColumn editable="false"
                                           headerText="FileType"
                                           dataField="fileFormat" width="80">
                            <mx:itemRenderer>
                                <mx:Component>
                                    <mx:HBox paddingLeft="5">
                                        <mx:Text styleName="normalText"
                                                 text="{'.' + data.fileFormat}"/>
                                    </mx:HBox>
                                </mx:Component>
                            </mx:itemRenderer>
                        </mx:DataGridColumn>
                    </commoncomponents:columns>
                </commoncomponents:ListDatagrid>