关于C#中的Static 关键字，用法和作用不必多说，大家耳熟能详的有 静态类、字段、方法、属性、运算符、事件和构造函数等等

静态方法，

public static void TestStaticMethod()
{
//...
}

类中的静态属性声明，

class TestA
{
    static int a = 10;
    //...

    public TestA(){}
}

最近在看项目代码想重构时，发现下面这段代码：我搞不懂为何要声明为static 的呀？我想请问的是我什么时候应该使用static声明一个方法？有最佳实践吗？

 public static HttpResponse GetResponse(HttpRequest request)
        {
            HttpWebRequest httpWebRequest = GetWebRequest(request);
            
            HttpResponse httpResponse = new HttpResponse(httpWebRequest.RequestUri.AbsoluteUri);
            HttpWebResponse httpWebResponse = null;
            try
            {
                httpWebResponse = (HttpWebResponse) httpWebRequest.GetResponse();
            }
            catch (WebException ex)
            {
                if (ex.Response != null)
                {
                    httpWebResponse = (HttpWebResponse) ex.Response;
                }
                else
                {
                    throw new ClientException(ex.ToString());
                }
            }
            catch (Exception ex)
            {
                throw new ClientException(ex.ToString());
            }
            return httpResponse;
        }