GridToolbar

Copy Codeclass App extends React.Component {
   state = {
      data: [
           {'Column1':'A1', 'Column2':'A2'},
           {'Column1':'B1', 'Column2':'B2'},
           {'Column1':'C1', 'Column2':'C2'}
       ]
   }

   customClick = () => {
       alert("Custom handler in custom toolbar");
   }
   render() {
       return (
          <Grid data={this.state.data}>
               <GridToolbar>
                   <button
                       title="Click"
                       className="k-button k-primary"
                       onClick={this.customClick}
                   >Click
                   </button>
               </GridToolbar>
           </Grid>
       );
   }
}
ReactDOM.render(
   <App />,
   document.querySelector('my-app')
);