我想做的是将我渲染的旧数组中的值插入到新数组中。
现在它可以完美地呈现我想要的数据，但是当我将它插入新数组时它变成 [id : undefined]
如何调用我从 ListView 呈现的 ticketId 以保存到 myState 数组中？
class SeactionSeating extends React.Component {
state = { ticket: [], myState: [] };
componentWillMount() {
const tempticket = [];
let i;
let k = 1;
let x;
for (i = 1; i <= 50; i++) {
k++;
if (i < 10) {
x = 'north';
} else if (i < 20) {
x = 'south';
} else if (i < 30) {
x = 'west';
} else if (i < 40) {
x = 'east';
}
tempticket.push({ ticketId: i, row: k, gate: x });
}
this.setState({ ticket: tempticket });
this.setState({ myState: [] });
//i deliberately leave mystate empty so that i can push new array later
}
render() {
const ticketTemp = () => {
this.state.myState.push({ id: ticketId });
console.log(this.state.myState);
};
return (
<Container>
<View style={styles.listViewTitlePanel}>
<Text> hello there</Text>
</View>
<Content>
<ScrollView>
<List>
{ this.state.ticket.map((item, i) => (
<ListItem
roundAvatar
key={i}
avatar={
<View >
<Text>{item.ticketId}</Text>
</View>
}
title={
<View>
<Text>ROW :{item.row}</Text>
</View>
}
subtitle={
<View>
<Text>GATE :{item.gate}</Text>
</View>
}
//call ticketTemp
onPress={ticketTemp}
/>
))
}
</List>
</ScrollView>
</Content>
</Container>
);
}
}
最佳答案
您应该将 trackId 传递给您的 ticketTemp 函数，它可以将此值推送到 myState 数组中。我就是这么做的。并且我将ticketTemp 函数转移到render 函数之外，因为修改状态的函数不能在render 内部。
你的代码必须是这样的:
class SeactionSeating extends React.Component {
state = { ticket: [], myState: [] };
componentWillMount() {
const tempticket = [];
let i;
let k = 1;
let x;
for (i = 1; i <= 50; i++) {
k++;
if (i < 10) {
x = 'north';
} else if (i < 20) {
x = 'south';
} else if (i < 30) {
x = 'west';
} else if (i < 40) {
x = 'east';
}
tempticket.push({ ticketId: i, row: k, gate: x });
}
this.setState({ ticket: tempticket });
// this.setState({ myState: [] }); //this line must be removed
//i deliberately leave mystate empty so that i can push new array later
}
ticketTemp(ticketId) {
this.state.myState.push({ id: ticketId });
console.log(this.state.myState);
};
render() {
return (
<Container>
<View style={styles.listViewTitlePanel}>
<Text> hello there</Text>
</View>
<Content>
<ScrollView>
<List>
{ this.state.ticket.map((item, i) => (
<ListItem
roundAvatar
key={i}
avatar={
<View >
<Text>{item.ticketId}</Text>
</View>
}
title={
<View>
<Text>ROW :{item.row}</Text>
</View>
}
subtitle={
<View>
<Text>GATE :{item.gate}</Text>
</View>
}
//call ticketTemp
onPress={() => this.ticketTemp(item.ticketId)}
/>
))
}
</List>
</ScrollView>
</Content>
</Container>
);
}
}
我做了一些改变，现在我运行没有错误，谢谢
关于javascript - React-native 将渲染数组中的值插入到新数组中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46335922/