TypeScript提取响应. -预期0个类型参数，但得到1个 [英] TypeScript Fetch response.Json<T> - Expected 0 type arguments, but got 1

问题描述

原谅我的无知，但是我试图在TypeScript中实现访存，并且我一直在浏览示例，但无法对其进行编译.我是TypeScript和Promise的新手，我找到了以下示例:

forgive my ignorance but I am trying to implement a fetch in TypeScript and I have been going through the examples but cannot get it to compile. I am new to TypeScript and Promise and I found this example:

如何在打字稿中使用提取

我正在尝试实现这一点:

And I am trying to implement this:

private api<T>(url: string): Promise<T> {
        return fetch(url)
          .then(response => {
            if (!response.ok) {
              throw new Error(response.statusText)
            }
            return response.json<T>()
          })          
}

但是编译器显示错误:

[ts]期望使用0个类型的参数，但得到1个.

[ts] Expected 0 type arguments, but got 1.

我不确定问题出在哪里，但是基本上我正在尝试实现一个包装API调用以返回项目数组的类，并且我已经尝试了async/await，但似乎没有任何工作.任何帮助将不胜感激.

I am not sure what the problem is but basically I am trying to implement a class which wraps the API calls to return an array of items and I have experimented with async/await and nothing seems to quite work. Any help would be greatly appreciated.

推荐答案

似乎签名不再存在，相反使用以下代码:

Seems that signature is not there anymore, Instead use this code:

response.json().then(data => data as T);

是的，这将为您返回强类型的数据. 下面是完整的代码片段.

Yeah, that will return you a strong typed data. Below the complete code snipped.

private api<T>(url: string): Promise<T> {
    return fetch(url)
      .then(response => {
        if (!response.ok) {
          throw new Error(response.statusText)
        }
        return response.json().then(data => data as T);
      })          
}

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