如何更改HttpRequestMessage的标头值-HowtochangeaheadervalueofHttpRequestMessage

In a validation setup I want to change the value of a header of a HttpRequestMessage.

在验证设置中，我想更改HttpRequestMessage的标头的值。

In a HttpClientHandler I have the following code:

在HttpClientHandler中，我有以下代码：

protected override async Task 
               SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
     //some condition when to alter the header

    //does not work: value is read only
    request.Headers.Single(c => c.Key == "FooHeader").Value = 
               new List({"aha!"}); 

    //does not work: cannot apply indexer
    request.Headers["FooHeader"] = "aha!"

    //does work but seems a bit overkill, besides I need to check if it exists
    request.Headers.Remove("FooHeader");
    request.Headers.Add("FooHeader", "aha!");
}

Is there a more intuitive way to achieve this?

有更直观的方法来实现这一目标吗？

1 个解决方案

public static class HttpRequestHeadersExtensions
{
    public static void Set(this HttpRequestHeaders headers, string name, string value)
    {
        if (headers.Contains(name)) headers.Remove(name);
        headers.Add(name, value);
    }
}

request.Headers.Set("FooHeader", "aha!");
request.Headers.Set("FooHeader", "ahaha!");