Extraire des données à partir de JSON liste de Réagir natif

Je veux analyser un fichier JSON et l'affichage des données sur l'écran. Je suis en mesure d'afficher toutes les données en utilisant le code suivant, mais je veux afficher seulement entryDate et sysol. Est-il possible d'utiliser une boucle for dans _onPressButtonGET() et d'afficher des données-il seulement?

       import React, { Component } from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View,
Navigator,
TouchableOpacity,
Image,
TouchableHighlight,
Alert,
TextInput
} from 'react-native';
import Button from 'react-native-button'
import {Actions} from 'react-native-router-flux'
import Home from './Home'
export class Temp extends Component{
constructor(props) {
super(props);
this.state = {
data: '',
data1:'',
textinput:'',
entryDate:[]
}
state={
shouldShow: false
}
}
componentDidMount(){
this._onPressButtonGET();
} 
_onPressButtonPOST(){
fetch(URL, {
method: "POST",  
headers: { 
'Accept': 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({
"entryDate":"3/2/2017 2:00 AM", 
"systol": this.state.textinput,
"mobileType":"ANDROID",
"userName":"menutest",
})})
.then((response) => response.json())
.then((responseData) => {
Alert.alert(                              
"Blood pressure data",
"Blood pressure data - " + JSON.stringify(responseData)
)
}).catch((error) => {
Alert.alert('problem while adding data');
})
.done(); 
}
_onPressButtonGET(){
fetch(url, {
method: "POST",
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
},
body: JSON.stringify({"mobileType":"ANDROID","userName":"menutest"})})
.then((response) => response.json())
.then((responseData) => {
this.setState({ data : JSON.stringify(responseData) })
data["list"].map(d => this.state.entryDate.push(d.entryDate));
this.setState({ entryDate: jsonResponse.entryDate, systol: responseData.systol })
}).catch((error) => {
Alert.alert('problem while getting data');
})
.done();
}
render(){
return(
<View>
<TouchableHighlight onPress={this._onPressButtonPOST.bind(this)}>
<Text>Add</Text> 
</TouchableHighlight>
<TouchableOpacity style= {{left:300,top:-20, }}
onPress={()=>{ this.setState({ shouldShow: !this.state.shouldShow })}}
><Text>Edit</Text></TouchableOpacity>
{this.state.shouldShow ? <TextInput placeholder='systol' 
onChangeText={(text) => this.setState({textinput: text})}
/> : null}
<TouchableHighlight onPress={this._onPressButtonGET.bind(this)}>
<Text>show</Text>
</TouchableHighlight>
this.state.entryDate.map( d => (<Text>{d}</Text>));
<Text>{this.state.entryDate}</Text> //not displaying anythong
<Text>{this.state.data && JSON.parse(this.state.data)['entryDate']}</Text> //not displaying anything
<Text>hello{this.state.data}</Text> //printing all data 
</View>
);
}
}
module.exports = Temp;

JSON:

{
"List": [
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "120"
},
{
"entryDate": "03/02/2017",
"entryDateTime": "03/02/2017 2:00 AM",
"entryTime": "2:00 AM",
"systol": "120"
}
]
}