如何在异步ASP.NET Web服务调用上定义客户端超时？

HttpClient client = new HttpClient();
client.Timeout = TimeSpan.FromSeconds(5);

using System.Threading.Tasks;

async Task CallWebServiceAsync()
{
    HttpClient client = new HttpClient();
    client.Timeout = TimeSpan.FromSeconds(5);

    // 发起异步调用
    Task<string> responseTask = client.GetStringAsync("https://example.com/api");

    // 等待指定的超时时间
    await Task.Delay(TimeSpan.FromSeconds(5));

    // 检查异步操作是否已完成
    if (!responseTask.IsCompleted)
    {
        // 取消异步操作或执行相应的处理逻辑
        client.CancelPendingRequests();
        // 其他处理逻辑...
    }
    else
    {
        // 异步操作已完成，获取结果
        string response = await responseTask;
        // 处理响应结果...
    }
}