如果你想推特定的索引，你可以这样做:

   const handleAddAfterIndex = index => {
       setTheArray(oldItems => {
            const copyItems = [...oldItems];
            const finalItems = [];
            for (let i = 0; i < copyItems.length; i += 1) {
                if (i === index) {
                    finalItems.push(copyItems[i]);
                    finalItems.push(newItem);
                } else {
                    finalItems.push(copyItems[i]);
                }
            }
            return finalItems;
        });
    };

// Save search term state to React Hooks with spread operator and wrapper function

// Using .concat(), no wrapper function (not recommended)
setSearches(searches.concat(query))

// Using .concat(), wrapper function (recommended)
setSearches(searches => searches.concat(query))

// Spread operator, no wrapper function (not recommended)
setSearches([...searches, query])

// Spread operator, wrapper function (recommended)
setSearches(searches => [...searches, query])

https://medium.com/javascript-in-plain-english/how-to-add-to-an-array-in-react-state-3d08ddb2e1dc

你可以在自定义状态的末尾追加数据数组:

  const [vehicleData, setVehicleData] = React.useState<any[]>([]);
  setVehicleData(old => [...old, ...newArrayData]);

例如，在下面，你会看到一个axios的例子:

  useEffect(() => {
    const fetchData = async () => {
      const result = await axios(
        {
          url: `http://localhost:4000/api/vehicle?page=${page + 1}&pageSize=10`,
          method: 'get',
        }
      );
      setVehicleData(old => [...old, ...result.data.data]);
    };

    fetchData();
  }, [page]);

我尝试了上面的方法将一个对象推入useState中的对象数组，但在使用TypeScript时出现以下错误:

类型“TxBacklog[] | undefined”必须有一个“符号”。Iterator的方法，返回一个Iterator .ts(2488)

tsconfig的设置。Json显然是正确的:

{
   "compilerOptions": {
   "target": "es6",
   "lib": [
      "dom",
      "dom.iterable",
      "esnext",
      "es6",
],

这个方法解决了问题(我的示例代码):

接口:

   interface TxBacklog {
      status: string,
      txHash: string,
   }

状态变量:

    const [txBacklog, setTxBacklog] = React.useState<TxBacklog[]>();

将新对象推入数组:

    // Define new object to be added
    const newTx = {
       txHash: '0x368eb7269eb88ba86..',
       status: 'pending'
    };
    // Push new object into array
    (txBacklog) 
       ? setTxBacklog(prevState => [ ...prevState!, newTx ])
       : setTxBacklog([newTx]);

最推荐的方法是同时使用包装函数和展开运算符。例如，如果你像这样初始化了一个名为name的状态，

控制[names, setNames] = useState(]

你可以像这样推到这个数组，

setNames(names => [...names, newName])

希望这能有所帮助。

如果你想推特定的索引，你可以这样做:

   const handleAddAfterIndex = index => {
       setTheArray(oldItems => {
            const copyItems = [...oldItems];
            const finalItems = [];
            for (let i = 0; i < copyItems.length; i += 1) {
                if (i === index) {
                    finalItems.push(copyItems[i]);
                    finalItems.push(newItem);
                } else {
                    finalItems.push(copyItems[i]);
                }
            }
            return finalItems;
        });
    };