更新状态的正确方式是什么，是一个嵌套对象，在与钩子反应？
export Example = () => {
const [exampleState, setExampleState] = useState(
{masterField: {
fieldOne: "a",
fieldTwo: {
fieldTwoOne: "b"
fieldTwoTwo: "c"
}
}
})
如何使用setexamplestat将examplestat更新为a（附加字段）？
const a = {
masterField: {
fieldOne: "a",
fieldTwo: {
fieldTwoOne: "b",
fieldTwoTwo: "c"
}
},
masterField2: {
fieldOne: "c",
fieldTwo: {
fieldTwoOne: "d",
fieldTwoTwo: "e"
}
},
}
}
b（更改值）？
const b = {masterField: {
fieldOne: "e",
fieldTwo: {
fieldTwoOne: "f"
fieldTwoTwo: "g"
}
}
})
您可以像这样传递新值
setExampleState({...exampleState, masterField2: {
fieldOne: "c",
fieldTwo: {
fieldTwoOne: "d",
fieldTwoTwo: "e"
}
},
}})
如果有人正在搜索useState（），则为object挂起更新
- Through Input
const [state, setState] = useState({ fName: "", lName: "" });
const handleChange = e => {
const { name, value } = e.target;
setState(prevState => ({
...prevState,
[name]: value
}));
};
<input
value={state.fName}
type="text"
onChange={handleChange}
name="fName"
/>
<input
value={state.lName}
type="text"
onChange={handleChange}
name="lName"
/>
***************************
- Through onSubmit or button click
setState(prevState => ({
...prevState,
fName: 'your updated value here'
}));
