Question

我有一个WPF应用程序，我用它来从Web API中提取数据。

登录后，我存储令牌，并根据您可以访问API。

案例1：登录，获取令牌，点击按钮获取数据：

private async void button1_Click(object sender, RoutedEventArgs e)
{
    getMovies();
}

实施方法

private void getMovies()
{
    var accessToken = token;
    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
    client.BaseAddress = new Uri("http://localhost:5001/movies/");
    client.DefaultRequestHeaders.Accept.Add(
        new MediaTypeWithQualityHeaderValue("application/json"));
    HttpResponseMessage response = client.GetAsync("get").Result;
    if (response.IsSuccessStatusCode)
    {
        MessageBox.Show(response.Content.ReadAsStringAsync().Result);
    }
    else
    {
        MessageBox.Show("Movies not Found");
    }
}

我收到了401。

案例2：我从Start方法调用API（与上面相同的代码）：从API获取数据

public async void Start(object sender, RoutedEventArgs e)
{
    getMovies();
}

这怎么可能？如何在Start方法之外访问我的API？

Answer 1

首先应该重构该方法以遵循通常建议的语法

string baseUrl = "http://localhost:5001/movies/"

private async Task getMoviesAsync() {
    var accessToken = token; //assuming token is being retrieved and set somewhere else
    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = 
        new AuthenticationHeaderValue("Bearer", accessToken);
    client.BaseAddress = new Uri(baseUrl);
    client.DefaultRequestHeaders.Accept
        .Add(new MediaTypeWithQualityHeaderValue("application/json"));
    var response = await client.GetAsync("get");
    if (response.IsSuccessStatusCode) {
        MessageBox.Show( await response.Content.ReadAsStringAsync());
    } else {
        MessageBox.Show("Movies not Found");
    }
}

并调用如下

private async void button1_Click(object sender, RoutedEventArgs e) {
    await getMoviesAsync();
}

通常不建议在永远调用时创建HttpClient，但这对于当前的问题来说是偏离主题的。

WPF应用访问Web API的奇怪行为

1 个答案: