React Router语言 - - 在 listen() 中区分 goBack() 和 goForward()

Question

Issue

使用 React Router v4，如何使用listen()方法区分goBack()和goForward()调用？

据我所知，location和action参数没有提供足够的信息来区分。action论点对后退和前进都POP。

history.listen((location, action) => {
// action = 'POP' when goBack() and goForward() are called.
}

我正在使用历史节点模块。

目的

我有一个面包屑组件，其项目处于状态。当用户返回时，我需要弹出最后一个面包屑。

Answer 1

您可以从数组中的location对象收集所有key值，并使用它来确定键是按顺序在前一个键之前还是之后，并使用它来区分goBack和goForward。

例

const keys = [];
let previousKey;
history.listen((location, action) => {
const { key } = location;
// If there is no key, it was a goBack.
if (key === undefined) {
console.log('goBack')
return;
}
// If it's an entirely new key, it was a goForward.
// If it was neither of the above, you can compare the index 
// of `key` to the previous key in your keys array.  
if (!keys.includes(key)) {
keys.push(key);
console.log('goForward');
} else if (keys.indexOf(key) < keys.indexOf(previousKey)) {
console.log('goBack');
} else {
console.log('goForward');
}
previousKey = key;
});
history.push("/test");
history.push("/test/again");
setTimeout(() => history.goBack(), 1000);
setTimeout(() => history.goBack(), 2000);
setTimeout(() => history.goForward(), 3000);