c#与webapi交互

public static string HttpConnectToServer(string ServerPage,string strData)
    {
        string postData =strData;
        //解决乱码问题
        byte[] dataArray = Encoding.UTF8.GetBytes(postData);
        //创建请求
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(ServerPage);
        request.Method = "POST";
        request.ContentLength = dataArray.Length;
        request.ContentType = "application/json;charset=UTF-8";
        //创建输入流
        Stream dataStream = null;
        try
        {
            dataStream = request.GetRequestStream();
        }
        catch (Exception)
        {
            return null;//连接服务器失败
        }

        //发送请求
        dataStream.Write(dataArray, 0, dataArray.Length);
        dataStream.Close();
        //读取返回消息
        string res = string.Empty;
        try
        {
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            res = reader.ReadToEnd();
            reader.Close();
        }
        catch (Exception ex)
        {
            return null;//连接服务器失败
        }
        return res;
    }