我是 React Native 的新手。我向 webservice 发出了一个获取请求，并将响应输入到一个列表中(我使用 native-base)。
我的问题是在 Android 上，对 web 服务的请求需要很长时间，例如最长 1 分钟，但在 iOS 上最长持续 20 秒，在网络上不超过 2 秒。
我认为我没有正确使用 React 的生命周期。谁能解释我如何升级它(如果可能的话)？或者如果我做错了就改变。
getTerrains() {
this.setState({
show: true
});
fetch(url, {
method: "POST",
headers: {
Accept: "application/text",
"Content-Type": "application/x-www-form-urlencoded"
},
body:
"surfaceID=" +
this.state.surface +
"&p_heureDebut=" +
this.state.start +
"&p_date=" +
this.state.date
}
)
.then(response =>
(*console.log(response)*, response.text())
)
.then(responseText => {
parseString(responseText, function(err, result) {
responseText = result;
});
let hTerrains = [];
for (let i = 0; i < responseText.Terrains.creneau.length; i++) {
let hStart = [];
let hEnd = [];
let terDesign = [];
let terIds = [];
hStart.push(responseText.Terrains.creneau[i].HEURE_DEBUT.toString());
hEnd.push(responseText.Terrains.creneau[i].HEURE_FIN.toString());
terDesign.push(
responseText.Terrains.creneau[i].TER_DESIGNATION.toString()
);
terIds.push(responseText.Terrains.creneau[i].TER_ID.toString());
hTerrains.push({
designation: terDesign,
st: hStart,
en: hEnd,
idT: terIds
});
this.setState({
// add for each element in this.state.rTerrains a table of values
tDesign: terDesign,
tStart: hStart,
tEnd: hEnd,
terID: terIds
});
}
this.setState({
rTerrains: hTerrains,
show: false
});
})
.catch(console.log);
}
和渲染:
renderTerrains() {
let terStart = [];
let index = 0;
let idTerrains = [];
let temp = "";
for (let item of this.state.rTerrains) {
idTerrains.push(item.designation);
terStart.push(
<ListItem key={index++} noBorder style={{ maxHeight: 60 }}>
<Left
style={
Platform.OS === "android"
? Platform.Version <= 22 ? { maxWidth: 30 } : { maxWidth: 50 }
: { maxWidth: 50 }
}
>
{temp.toString() !== item.designation.toString() ? (
<Text style={{ color: "#6abe51" }}>T{item.designation} </Text>
) : (
<Text />
)}
</Left>
<Body
style={{
alignItems: "center",
flexDirection: "row",
flex: 1,
minWidth: 80
}}
>
<Text style={styles.blue_color}>
{" "}
de {item.st} à {item.en}{" "}
</Text>
</Body>
<Right style={{ minWidth: 90 }}>
<Button
light
active
onPress={() => {
this.setState({
id: item.designation,
begin: item.st,
finish: item.en,
tId: item.idT
});
this.handleChangeValidation();
}}
>
<Text uppercase style={{ color: "#6abe51" }}>
Réserver
</Text>
</Button>
</Right>
</ListItem>
);
temp = item.designation;
}
return terStart;
}
构造函数和状态:
constructor(props) {
super(props);
this.state = {
date:
Platform.OS === "android"
? today.getDate() +
"/" +
(today.getMonth() + 1) +
"/" +
today.getFullYear()
: today.getMonth() +
1 +
"/" +
today.getDate() +
"/" +
today.getFullYear(),
dates: [],
surface: 1,
surfaces: [],
start: ("0" + today.getHours()).slice(-2),
hours: [],
rTerrains: [],
begin: "",
tStart: [],
finish: "",
tEnd: [],
id: "",
tDesign: []
};
this.getTerrains = this.getTerrains.bind(this);
this.getPlayer = this.getPlayer.bind(this);
this.addReservation = this.addReservation.bind(this);
this.handleChangeDate = this.handleChangeDate.bind(this);
this.handleChangeSurface = this.handleChangeSurface.bind(this);
this.handleChangeStart = this.handleChangeStart.bind(this);
this.handleChangeValidation = this.handleChangeValidation.bind(this);
this.handleChangeCreation = this.handleChangeCreation.bind(this);
}
以及这些函数的调用:
<Content>
<ListItem>
<Button
style={{alignItems: 'center', flex: 1, backgroundColor: '#06407e', borderRadius: 15}}
onPress={this.getTerrains}>
<Text style={{alignItems: 'center', textAlign: 'center', flex: 1}}>Rechercher</Text>
</Button>
</ListItem>
</Content>
<Content style={{margin: 2, backgroundColor: "white"}}>
<Content style={{margin: 20}}>
<Text
uppercase
style={styles.blue_color}>Terrains disponibles : </Text>
</Content>
<List>
{
this.renderTerrains()
}
</List>
</Content>
console.log(response) 的结果:
Response {
"_bodyInit": "<?xml version=\"1.0\" encoding=\"utf-8\"?>
<Terrains>
<creneau>
<TER_ID>3b5403ba-14fd-4317-aeef-7d2e56c7c479</TER_ID>
<TER_DESIGNATION>1</TER_DESIGNATION>
<HEURE_DEBUT>20:00</HEURE_DEBUT>
<HEURE_FIN>21:00</HEURE_FIN>
</creneau>
<creneau>
<TER_ID>b671dc7c-4f18-4e2d-900c-0c41529ad190</TER_ID>
<TER_DESIGNATION>12</TER_DESIGNATION>
<HEURE_DEBUT>20:00</HEURE_DEBUT>
<HEURE_FIN>21:00</HEURE_FIN>
</creneau>
<creneau>
<TER_ID>9f84fbc0-b797-4e58-adbf-43695ef88d3f</TER_ID>
<TER_DESIGNATION>3</TER_DESIGNATION>
<HEURE_DEBUT>20:00</HEURE_DEBUT>
<HEURE_FIN>21:00</HEURE_FIN>
</creneau>
<creneau>
<TER_ID>4e2f4322-85d0-44eb-b210-a7e35a2edeb1</TER_ID>
<TER_DESIGNATION>5</TER_DESIGNATION>
<HEURE_DEBUT>20:00</HEURE_DEBUT>
<HEURE_FIN>21:00</HEURE_FIN>
</creneau>
<creneau>
<TER_ID>d6c7d508-fb72-4d91-a5f7-fc17d040f528</TER_ID>
<TER_DESIGNATION>7</TER_DESIGNATION>
<HEURE_DEBUT>20:00</HEURE_DEBUT>
<HEURE_FIN>21:00</HEURE_FIN>
</creneau>
</Terrains>",
"headers": Headers {
"map": Object {
"cache-control": Array [
"private, max-age=0",
],
"content-length": Array [
"1064",
],
"content-type": Array [
"text/xml; charset=utf-8",
],
"date": Array [
"Fri, 02 Feb 2018 12:25:56 GMT",
],
"server": Array [
"Microsoft-IIS/8.5",
],
"x-aspnet-version": Array [
"4.0.30319",
],
"x-powered-by": Array [
"ASP.NET",
],
},
},
"ok": true,
"status": 200,
"statusText": undefined,
"type": "default",
}
最佳答案
不是fetch API的问题，是解析海量响应数据的问题，因为解析数据在react-native中是一个非常昂贵的任务，需要优化，在 ListView 中，如果可以的话，可以提供更好的解决方案分享您的回复数据。
关于android - react native 获取请求非常慢的android，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48578371/