Javascript 反应:反应选择的默认值
我有一个简单的列表,其中使用Javascript 反应:反应选择的默认值,javascript,reactjs,Javascript,Reactjs,我有一个简单的列表,其中使用.map显示循环选择 一切正常,但每个select的初始默认值不是数组列表中的值 如何为列表中的每个选择设置defaultValue import React,{useState}来自“React”; 从“反应选择”导入选择; 功能选择项(道具){ const[value,setValue]=React.useState(props.list[0]); 返回( { 设置值(新值); props.onChange(newValue.value); }} value={
.map
显示循环选择
一切正常,但每个select
的初始默认值不是数组列表中的值
如何为列表中的每个选择设置defaultValue
import React,{useState}来自“React”;
从“反应选择”导入选择;
功能选择项(道具){
const[value,setValue]=React.useState(props.list[0]);
返回(
{
设置值(新值);
props.onChange(newValue.value);
}}
value={value}
/>
);
}
导出默认值()=>{
常数animationsList=[
{value:“animation1”,标签:“Dance”},
{值:“动画2”,标签:“翻转”},
{值:“animation3”,标签:“Salsa”}
];
常量反应列表=[
{
id:“1”,
动画:“动画1”
},
{
id:“2”,
动画:“动画2”
},
{
id:“3”,
动画:“动画3”
}
];
const[links,setLinks]=useState(reactList);
const onChange=(索引,动画)=>{
常量克隆链接=[…链接];
克隆链接[索引]。动画=动画;
设置链接(克隆链接);
console.log(克隆链接);
};
返回(
{links.map((url,indexurl)=>(
-
onChange(indexurl,动画)}
list={animationsList}
defaultValue={url.animation.value}
/>
))}
);
};
不需要在SelectItem
组件中设置新状态
值
或默认值
必须是列表中用于选项的对象
这是最新消息
功能选择项(道具){
返回(
{
props.onChange(newValue.value);
}}
value={props.value}
/>
);
}
导出默认值()=>{
常数animationsList=[
{value:“animation1”,标签:“Dance”},
{值:“动画2”,标签:“翻转”},
{值:“animation3”,标签:“Salsa”}
];
常量反应列表=[
{
id:“1”,
动画:“动画1”
},
{
id:“2”,
动画:“动画2”
},
{
id:“3”,
动画:“动画3”
}
];
const[links,setLinks]=useState(reactList);
const onChange=(索引,动画)=>{
常量克隆链接=[…链接];
克隆链接[索引]。动画=动画;
设置链接(克隆链接);
console.log(克隆链接);
};
返回(
{links.map((url,indexurl)=>(
-
onChange(indexurl,动画)}
list={animationsList}
值={animationsList.find(
(aL)=>aL.value==url.animation
)}
/>
))}
);
};
非常感谢。你能解释一下这句话吗(aL)=>aL.value==url.animation
@AlyaKra我正在animationlist
中找到对象。值
和动画
属性在这两个对象之间是相等的。我明白了。再次非常感谢。很高兴能帮忙。如果您的问题得到解决,您能否将此标记为正确答案?
import React, { useState } from "react";
import Select from "react-select";
function SelectItem(props) {
const [value, setValue] = React.useState(props.list[0]);
return (
<Select
options={props.list}
onChange={(newValue) => {
setValue(newValue);
props.onChange(newValue.value);
}}
value={value}
/>
);
}
export default () => {
const animationsList = [
{ value: "animation1", label: "Dance" },
{ value: "animation2", label: "Flip" },
{ value: "animation3", label: "Salsa" }
];
const reactList = [
{
id: "1",
animation: "animation1"
},
{
id: "2",
animation: "animation2"
},
{
id: "3",
animation: "animation3"
}
];
const [links, setLinks] = useState(reactList);
const onChange = (index, animation) => {
const cloneLinks = [...links];
cloneLinks[index].animation = animation;
setLinks(cloneLinks);
console.log(cloneLinks);
};
return (
<div>
<ul>
<div>
{links.map((url, indexurl) => (
<li key={url.id}>
<div>
<SelectItem
onChange={(animation) => onChange(indexurl, animation)}
list={animationsList}
defaultValue={url.animation.value}
/>
</div>
</li>
))}
</div>
</ul>
</div>
);
};
function SelectItem(props) {
return (
<Select
options={props.list}
onChange={(newValue) => {
props.onChange(newValue.value);
}}
value={props.value}
/>
);
}
export default () => {
const animationsList = [
{ value: "animation1", label: "Dance" },
{ value: "animation2", label: "Flip" },
{ value: "animation3", label: "Salsa" }
];
const reactList = [
{
id: "1",
animation: "animation1"
},
{
id: "2",
animation: "animation2"
},
{
id: "3",
animation: "animation3"
}
];
const [links, setLinks] = useState(reactList);
const onChange = (index, animation) => {
const cloneLinks = [...links];
cloneLinks[index].animation = animation;
setLinks(cloneLinks);
console.log(cloneLinks);
};
return (
<div>
<ul>
<div>
{links.map((url, indexurl) => (
<li key={url.id}>
<div>
<SelectItem
onChange={(animation) => onChange(indexurl, animation)}
list={animationsList}
value={animationsList.find(
(aL) => aL.value === url.animation
)}
/>
</div>
</li>
))}
</div>
</ul>
</div>
);
};