Javascript 如何侦听react钩子中的redux状态更改?
我有多个表单和按钮,用户可以编辑现在我想显示一个按钮保存,如果redux的状态改变 现场演示: 这是我的reduxJavascript 如何侦听react钩子中的redux状态更改?,javascript,reactjs,input,redux,react-redux,Javascript,Reactjs,Input,Redux,React Redux,我有多个表单和按钮,用户可以编辑现在我想显示一个按钮保存,如果redux的状态改变 现场演示: 这是我的redux const initialState = { firstName: "Kunta ", lastName: "Kinte", age: 35, country: "Ghana", color: "#000" }; const DetailsReducer = (state = in
const initialState = {
firstName: "Kunta ",
lastName: "Kinte",
age: 35,
country: "Ghana",
color: "#000"
};
const DetailsReducer = (state = initialState, action) => {
const { name, value } = action;
return { ...state, [name]: value };
};
export default DetailsReducer;
下面是我的js代码,如果redux状态发生变化,它将显示save按钮
import React, { useState, useEffect } from "react";
import { useSelector, useDispatch } from "react-redux";
const Settings = () => {
const fields = useSelector((state) => state);
const dispatch = useDispatch();
const [saveBtn, setSaveBtn] = useState(false);
useEffect(() => {
setSaveBtn(true); // show save btn if there is changes in state
}, []);
console.log(fields.firstName);
return (
<div>
<div>
<h1>Edit </h1>
First Name:{" "}
<input
name="firstname"
value={fields.firstName}
onChange={(e) =>
dispatch({ name: "firstName", value: e.target.value, type: "" })
}
/>
{saveBtn === true && <button className="btn-save">save </button>}
</div>
</div>
);
};
export default Settings;
[1]: https://codesandbox.io/s/multiple-inputs-kkm6l?file=/src/Components/Settings.js:0-816
import React,{useState,useffect}来自“React”;
从“react-redux”导入{useSelector,useDispatch};
常量设置=()=>{
常量字段=使用选择器((状态)=>状态);
const dispatch=usedpatch();
const[saveBtn,setSaveBtn]=useState(false);
useffect(()=>{
setSaveBtn(true);//如果状态发生更改,则显示save btn
}, []);
console.log(fields.firstName);
返回(
编辑
名字:{'}
分派({name:“firstName”,值:e.target.value,类型:”“})
}
/>
{saveBtn==true&&save}
);
};
导出默认设置;
[1]: https://codesandbox.io/s/multiple-inputs-kkm6l?file=/src/Components/Settings.js:0-816
我需要做什么来解决这个问题?您可以尝试以下方法:
<input
name="firstname"
value={fields.firstName}
onChange={(e) =>
dispatch({ name: "firstName", value: e.target.value, type: "" }, setSaveBtn(true))
}
/>
你可以这样做。移除效果挂钩,将setSaveBtn移动到input onChange,然后单击save,将setSaveBtn设置为false
import React, { useState, useEffect } from "react";
import { useSelector, useDispatch } from "react-redux";
const Settings = () => {
const fields = useSelector((state) => state);
const dispatch = useDispatch();
const [saveBtn, setSaveBtn] = useState(false);
console.log(fields.firstName);
return (
<div>
<div>
<h1>Edit </h1>
First Name:{" "}
<input
name="firstname"
value={fields.firstName}
onChange={(e) => {
dispatch({ name: "firstName", value: e.target.value, type: "" })
setSaveBtn(true)
}}
/>
{saveBtn === true &&
<button
onClick={() => setSaveBtn(false)}
className="btn-save">save </button>}
</div>
</div>
);
};
export default Settings;
import React,{useState,useffect}来自“React”;
从“react-redux”导入{useSelector,useDispatch};
常量设置=()=>{
常量字段=使用选择器((状态)=>状态);
const dispatch=usedpatch();
const[saveBtn,setSaveBtn]=useState(false);
console.log(fields.firstName);
返回(
编辑
名字:{'}
{
分派({name:“firstName”,值:e.target.value,类型:”“})
setSaveBtn(真)
}}
/>
{saveBtn===true&&
setSaveBtn(假)}
className=“btn保存”>保存}
);
};
导出默认设置;
所以我需要在ech输入上执行此设置VAEBTN?这是错误的,我只想要一个函数,它可以检测状态是否发生了变化,然后做些什么
import React, { useState, useEffect } from "react";
import { useSelector, useDispatch } from "react-redux";
const Settings = () => {
const fields = useSelector((state) => state);
const dispatch = useDispatch();
const [saveBtn, setSaveBtn] = useState(false);
console.log(fields.firstName);
return (
<div>
<div>
<h1>Edit </h1>
First Name:{" "}
<input
name="firstname"
value={fields.firstName}
onChange={(e) => {
dispatch({ name: "firstName", value: e.target.value, type: "" })
setSaveBtn(true)
}}
/>
{saveBtn === true &&
<button
onClick={() => setSaveBtn(false)}
className="btn-save">save </button>}
</div>
</div>
);
};
export default Settings;