setState改变后Marker不生效（数组减少）

Created by: jnzw1986

render() { return <MapView ref={ref => this.mapView = ref} style={styles.body}>

      {
          this.state.dataSource.map((item,i)=>this.renderExpenseItem(item,i))
      }

  </MapView>

}

renderExpenseItem(dataItem , i) { key=${i}${Date.now()} var keyvalue = ${i}${Date.now()} console.log("_keyvalue=="+${keyvalue}); return <Marker key = {keyvalue} title='自定义 View' icon={() => {${i}+ "_title"} } coordinate={dataItem} /> }

_changeNilAction = () => { this.setState({ dataSource:[] }) }