Añadiendo un boton

src/webparts/homeDetailsList/components/HomeDetailsList.tsx

@@ -6,6 +6,7 @@ import { DetailsList, DetailsListLayoutMode, Selection, IColumn } from 'office-u
 import { MarqueeSelection } from 'office-ui-fabric-react/lib/MarqueeSelection';
 import { Fabric } from 'office-ui-fabric-react/lib/Fabric';
 import { mergeStyles } from 'office-ui-fabric-react/lib/Styling';
+import { PrimaryButton } from '@microsoft/office-ui-fabric-react-bundle';
 
 
 const exampleChildClass = mergeStyles({
@@ -89,7 +90,12 @@ export default class HomeDetailsList extends React.Component<IHomeDetailsListPro
 
   public render(): React.ReactElement<IHomeDetailsListProps> {
     const { items, itemsAux, selectionDetails } = this.state;
-   
+    const {disabled, checked} = this.props
+    
+    function _alertClicked(): void {
+      alert('Clicked');
+    }
+    
 
     return (
       <Fabric>
@@ -115,6 +121,11 @@ export default class HomeDetailsList extends React.Component<IHomeDetailsListPro
             checkButtonAriaLabel="Row checkbox"
             onItemInvoked={this._onItemInvoked}
           />
+          <br />
+          <PrimaryButton text="Añadir Productos" onClick={_alertClicked} allowDisabledFocus disabled={disabled} checked={checked} />
+          <div>
+
+          </div>
         </MarqueeSelection>
       </Fabric>
     );

src/webparts/homeDetailsList/components/IHomeDetailsListProps.ts

 export interface IHomeDetailsListProps {
   description: string;
+  disabled?: boolean;
+  checked?: boolean;
 }