Hello Ying,

Thank you for posting in our community.

If you want to provide a custom template which will be applied when a cell is in edit mode, you can make use of the igxCellEditor directive. To do this, you need to pass an ng-template with the igxCellEditor directive and properly bind your custom control to the cell.editValue:

<igx-column field="Locations" header="Available At" [editable]="true" [filterable]="false" width="220px">
	<ng-template igxCell let-cell="cell">
		{{ parseArray(cell.value) }}
	</ng-template>
	<ng-template igxCellEditor let-cell="cell" let-value>
		<igx-combo type="line" [(ngModel)]="cell.editValue" [displayKey]="'shop'" [data]="locations" width="220px"></igx-combo>
	</ng-template>
</igx-column>

My suggestion is to take a look at our sample from the documentation page about grid cell editing and edit templates.