ajax：前后端json传值写法

女爷i 2021-09-15 07:08 397阅读 0赞

ajax中的contentType有多种类型，默认是contentType=application/x-www-form-urlencoded;charset=utf-8;，如果设置contentType=application/json;charset=utf-8;那就会发生在后台无法通过context.Request.Form\[\]获取参数的情况，下面我就post、get两种方式进行梳理。

## post传值 ##

前台代码，data是json字符串：

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后台取值：

public void ProcessRequest(HttpContext context)
    {
        try
        {
            #region Form取值(不行)
            //string contentType = context.Request.Form["contentType"].ToString();
            //string param2 = context.Request.Form["param2"].ToString();
            #endregion
    
            #region InputStream取值（可以）
            Stream stream = context.Request.InputStream;
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            string parameters = Encoding.Default.GetString(bytes);
            JObject jObject = (JObject)JsonConvert.DeserializeObject(parameters);
            string contentType = jObject["contentType"].ToString();
            string param2 = jObject["param2"].ToString(); 
            #endregion 
        }
        catch (Exception ex)
        {
            context.Response.Write("error");
        }
    }

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前台代码，data是json对象：

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后台取值：

public void ProcessRequest(HttpContext context)
    {
        try
        {
            #region Form取值(不行)
            //string contentType = context.Request.Form["contentType"].ToString();
            //string param2 = context.Request.Form["param2"].ToString();
            #endregion
    
            #region InputStream取值（不行）
            Stream stream = context.Request.InputStream;
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            string parameters = Encoding.Default.GetString(bytes);
            JObject jObject = (JObject)JsonConvert.DeserializeObject(parameters);
            string contentType = jObject["contentType"].ToString();
            string param2 = jObject["param2"].ToString(); 
            #endregion 
        }
        catch (Exception ex)
        {
            context.Response.Write("error");
        }
    }

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## get传值 ##

前台代码，data是json字符串：

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后台取值：

public void ProcessRequest(HttpContext context)
    {
        try
        {
            #region QueryString取值（不行）
            //string contentType = context.Request.QueryString["contentType"].ToString();
            //string param2 = context.Request.QueryString["param2"].ToString();
            #endregion
    
            #region InputStream取值（不行）
            Stream stream = context.Request.InputStream;
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            string parameters = Encoding.Default.GetString(bytes);
            JObject jObject = (JObject)JsonConvert.DeserializeObject(parameters);
            string contentType = jObject["contentType"].ToString();
            string param2 = jObject["param2"].ToString();
            #endregion
        }
        catch (Exception ex)
        {
            context.Response.Write("error");
        }
    }

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前台代码，data是json对象：

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后台取值：

public void ProcessRequest(HttpContext context)
    {
        try
        {
            #region QueryString取值（可以）
            string contentType = context.Request.QueryString["contentType"].ToString();
            string param2 = context.Request.QueryString["param2"].ToString();
            #endregion
    
            #region InputStream取值（不行）
            //Stream stream = context.Request.InputStream;
            //byte[] bytes = new byte[stream.Length];
            //stream.Read(bytes, 0, bytes.Length);
            //string parameters = Encoding.Default.GetString(bytes);
            //JObject jObject = (JObject)JsonConvert.DeserializeObject(parameters);
            //string contentType = jObject["contentType"].ToString();
            //string param2 = jObject["param2"].ToString();
            #endregion
        }
        catch (Exception ex)
        {
            context.Response.Write("error");
        }
    }

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## 总结 ##

当contentType=application/json;charset=utf-8;时，post传值只有在data是json字符串后台用InputStream进行解析，才能获取参数；   
当contentType=application/json;charset=utf-8;时，get传值只有在data是json对象后台用QueryString进行解析，才能获取参数。