---

前言

一般http请求都是由浏览器端发送的，当然C#也可以借助一些类来达到发送请求，这样就可以使用C#来作为前端访问我们java/python后端了

---

一、Http工具类

示例：在这里我们来使用两种方式访问后端的接口

1.HttpWebRequest

推荐该方式，封装后可返回response数据然后进行逻辑处理

class HttpRequest
{
    public static string baseUrl = "http://localhost:8089";

    public static String createGet(String url)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(baseUrl + url);
        request.Method = "GET";
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        Stream getStream = response.GetResponseStream();
        StreamReader streamreader = new StreamReader(getStream);
        String result = streamreader.ReadToEnd();
        streamreader.Close();
        return result;
    }

    public static String createPost(String url, string postDataStr)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(baseUrl + url);
        request.Method = "POST";
        request.ContentType = "application/json;charset=UTF-8";
        request.ContentLength = postDataStr.Length;
        StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
        writer.Write(postDataStr);
        writer.Flush();
        writer.Close();
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        string encoding = response.ContentEncoding;
        if (encoding == null || encoding.Length < 1)
        {
            encoding = "UTF-8";
        }
        StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
        string retString = reader.ReadToEnd();
        reader.Close();
        return retString;
    }
}

在这里我们可以把结果封装为一个Result类

class Result
{
     public string message { get; set; }
     public Object data { get; set; }
     public int status { get; set; }
 }

点击第一个测试按钮，然后在米革命空间引入using Newtonsoft.Json就可以使用JsonConvert来转换结果为Result了

private void btnLogin_Click(object sender, EventArgs e)
{
    String str = HttpRequest.createPost("/api/user/login?account=xxx&password=xxx", "");
    Result result = JsonConvert.DeserializeObject<Result>(str);
    Console.WriteLine(result);
    if (result.status == 100)
    {
        MessageBox.Show("SUCCESS", "HI");
    }
}

2.HttpClient

在该方式中演示转为对象实体类

public class AngelHttpClient
{

    private HttpClient httpClient;

    public AngelHttpClient()
    {
        httpClient = new HttpClient() { BaseAddress = new Uri("http://127.0.0.1:8089") };
        httpClient.Timeout = new TimeSpan(0, 0, 0, 3);
    }

    public SysUserVO userLogin(string account, string password)
    {
        string url = "/api/user/user_login?account="+account+"&password="+password;
        HttpResponseMessage response = new HttpResponseMessage();
        try
        {
            response = httpClient.PostAsync(url, null).Result;
            string respStr = response.Content.ReadAsStringAsync().Result;
            LogHelper.WriteLog("respStr:" + respStr);
            var respData = JsonHelper.DeserializeAnonymousType(respStr, new { data = new SysUserVO(), message = "", status = 101 });
            if (respData.status != 100)
            {
                /*MessageBox.Show("登录失败！" + respData.message);*/
                Console.WriteLine("登录失败！" + respData.message);
                return null;
            }
            /*SysUserVO person = JsonHelper.DeserializeJsonToObject<SysUserVO>(respData.data);*/
            return respData.data;
        }
        catch (Exception ex)
        {
            LogHelper.WriteLog("HTTP request failed." + ex);
            return null;
        }
    }

}

我们先来建SysUser和SysUserVO，VO继承SysUser并添加了个token属性

public class SysUser
{
    public int userId { get; set; }
    public string userAccount { get; set; }
    public string userPasswd { get; set; }
    public string userName { get; set; }
    public bool deleteFlag { get; set; }
    public override string ToString()
    {
        return "userName: " + userName + ", userAccount:" + userAccount;
    }
}

public class SysUserVO : SysUser
{
    public string token { get; set; }
    public override string ToString()
    {
        return "userName: " + userName + ", userAccount:" + userAccount + ", token:"+token;
    }
}

然后我们就可以去测试了，JsonHelper代码在下面

private void btnSuper_Click(object sender, EventArgs e)
{
    AngelHttpClient angelHttpClient = new AngelHttpClient();
    SysUserVO s = angelHttpClient.userLogin("xxx", "xxx");
    Console.WriteLine(s);
}

二、转换结果

1.JsonHelper

可以使用帮助类然后将response中的data封装为实体类对象

class JsonHelper
{

    /// <summary>
    /// 将对象序列化为JSON格式
    /// </summary>
    public static string SerializeObject(object o)
    {
        string json = JsonConvert.SerializeObject(o);
        return json;
    }

    /// <summary>
    /// 解析JSON字符串生成对象实体
    /// </summary>
    public static T DeserializeJsonToObject<T>(string json) where T : class
    {
        JsonSerializer serializer = new JsonSerializer();
        StringReader sr = new StringReader(json);
        object o = serializer.Deserialize(new JsonTextReader(sr), typeof(T));
        T t = o as T;
        return t;
    }

    /// <summary>
    /// 解析JSON数组生成对象实体集合
    /// </summary>
    public static List<T> DeserializeJsonToList<T>(string json) where T : class
    {
        JsonSerializer serializer = new JsonSerializer();
        StringReader sr = new StringReader(json);
        object o = serializer.Deserialize(new JsonTextReader(sr), typeof(List<T>));
        List<T> list = o as List<T>;
        return list;
    }

    /// <summary>
    /// 反序列化JSON到给定的匿名对象.
    /// </summary>
    public static T DeserializeAnonymousType<T>(string json, T anonymousTypeObject)
    {
        T t = JsonConvert.DeserializeAnonymousType(json, anonymousTypeObject);
        return t;
    }

}

2.LogHelper

简单的日志输出

class LogHelper
{

    public static readonly log4net.ILog loginfo = log4net.LogManager.GetLogger("loginfo");
    public static readonly log4net.ILog logerror = log4net.LogManager.GetLogger("logerror");

    public static void WriteLog(string info)
    {
        if (loginfo.IsInfoEnabled)
        {
            loginfo.Info(info);
        }
    }

    public static void WriteLog(string info, Exception ex)
    {
        if (logerror.IsErrorEnabled)
        {
            logerror.Error(info, ex);
        }
    }

}

---

总结

感谢观看