Pull to refresh not working

Pull to refresh feauture not working

` _onRefresh=()=> {
this.setState({refreshing: true});
const{username}=this.state;
this.props.getInspiration({username,offset:0})
.then(r=>{
this.setState({posts.data.posts,refreshing: false})
});
}`

` 1}
data={this.state.posts}
renderItem={(item)=>}
/>`

If i set refreshing=true, the loading indicator shows, however when I pull to call my _onRefresh function, nothing happens.