Question

说我正在使用以下类型的模块：

interface AwesomeLibrary {
    name: string;
    query: Object;
}

我想将query类型转换为另一个界面：

interface Query {
    startDate: string;
    endDate: string;
    showAll: boolean;
}

让我们说有一个函数回调给我AwesomeLibrary。我想将query强制转换为Query。现在这就是我的全部：

functionCb(response: AwesomeLibrary) {
    // This works fine
    let query: Query = response.query as Query;
    // Now, query.startDate is available
    // Do stuff to query
    // At the end, I want to send response back to another function, so I do
    response.query = query;
    otherFunction(response);

    // This does not work, but basically what I want:
    response.query = response.query as Query;
    // Then do stuff to response.query directly
    // Here response.query.startDate is not available, instead I have to use response.query['startDate']

    // Even this does not work:
    let query: Query = response.query as Query;
    response.query = query;
}

思想？

Answer 1

你可以像这样输入：

(response.query as Query).startDate = (new Date()).toUTCString();

或者你可以有另一个变量：

let response2 = response as AwesomeLibrary & { query: Query };
response2.query.startDate = (new Date()).toUTCString();

您还可以接收此类型的参数：

function functionCb(response: AwesomeLibrary & { query: Query }) {
    response.query.startDate = (new Date()).toUTCString();
}

但是在调用此函数时你需要进行转换。

打字稿类型转换现有变量

1 个答案: