C# 将 Json 对象转换为 DataTable以及[WebMethod]方法接收前端传入的JsonArray的方法、抛出 JsonSerializationException的原因

绝地灬酷狼 2024-02-29 03:48 22阅读 0赞

其他的一些转化可以参考我的另一篇文章[https://blog.csdn.net/munangs/article/details/133950243][https_blog.csdn.net_munangs_article_details_133950243]

## 将Json 数据转换为 DataTable ##

**未被JSON.stringify处理之前的数据张这样**

[
             {
        
                "Id":"0",
                "Username":"Vreeswijk",
                "ProfilePicture":"media/user/0.png"
             },
             {
        
                "Id":"1",
                "Username":"Mony",
                "ProfilePicture":"media/user/12.png"
             }
          ]

在前台用js JSON.stringify处理过才传给后台，后台进行处理
    //GET请求
    public void test(string printList)
    
    var dt = (DataTable)JsonConvert.DeserializeObject(printList,typeof(DataTable));
    
    //传递给数据库
    SqlParameter[] sql = new SqlParameter[1];
    sql[0] = new SqlParameter('dt',dt);
    
    //GET请求
    public void test(string printList)
    
    var dt = (DataTable)JsonConvert.DeserializeObject(printList,typeof(DataTable));
    
    //传递给数据库
    SqlParameter[] sql = new SqlParameter[1];
    sql[0] = new SqlParameter('dt',dt);
    ----------------------------------------------------------------------------------
    //如果是在JSON中获取
    {
        
       "data": [
             {
        
                "Id":"0",
                "Username":"Vreeswijk",
                "ProfilePicture":"media/user/0.png"
             },
             {
        
                "Id":"1",
                "Username":"Mony",
                "ProfilePicture":"media/user/12.png"
             }
          ]
    }
    
    var jObject = JObject.Parse(json);
    var printList= jObject["printList"] as string;
    
    var dt = (DataTable)JsonConvert.DeserializeObject(printList,typeof(DataTable));
    
    //传递给数据库
    SqlParameter[] sql = new SqlParameter[1];
    sql[0] = new SqlParameter('dt',dt);

## 其他将 Json 对象转换为 DataTable方法，其一 ##

string s = "{\n  \"Flag\": 1,\n  \"Data\": [\n    {\n      \"id\": 37,\n      \"pid\": \"105226\",\n      \"PName\": \"韩友庆\",\n      \"IName\": \"X线计算机体层（CT）平扫（1层-8层）\",\n      \"CName\": \"超声五室\",\n      \"Times\": \"10:00:00-14:00:00\",\n      \"checkdate\": \"2023-07-12T00:00:00\"\n    },\n    {\n      \"id\": 38,\n      \"pid\": \"105219\",\n      \"PName\": \"翟金花\",\n      \"IName\": \"X线计算机体层（CT）平扫（1层-8层）\",\n      \"CName\": \"超声五室\",\n      \"Times\": \"10:00:00-14:00:00\",\n      \"checkdate\": \"2023-07-12T00:00:00\"\n    }\n  ],\n  \"Msg\": \"\"\n}";
     JObject json = JObject.Parse(s);
    JArray array = new JArray();
    var d = json["Data"];
    foreach(var a in d){
        
        array.Add(a);
    }
               
    dt = JsonConvert.DeserializeObject<DataTable>(array.ToString());

抛出 JsonSerializationException的原因  
“容器”必须是 JArray。

错误的简单示例:

JObject query = new JObject();
    JObject results = new JObject();
     
    results.Add("Name", "Blue Umbrella");
    results.Add("Price", 100);
     
    query.Add("results", results);
     
    DataTable dt = (DataTable)JsonConvert.DeserializeObject(query.ToString(), (typeof(DataTable)));

## 其二 ##

1、使用Newtonsoft.Json库，将JSON数据转换为实体类，其中实体类的属性要和JSON数据的键值对应起来。

public class Student
    {
        
    	public string Name {
         get; set; }
    	public string Age {
         get; set; }
    	public string Sex {
         get; set; }
    }

2、使用反射机制，将实体类的属性值转换为DataTable的列名，即DataTable的列名就是实体类的属性名。

// 定义DataTable
    DataTable dt = new DataTable();
    // 反射实体类属性
    PropertyInfo[] propertyInfos = typeof(Student).GetProperties();
    // 将实体类属性转换为DataTable的列名
    foreach (PropertyInfo propertyInfo in propertyInfos)
    {
        
         dt.Columns.Add(propertyInfo.Name);
    }

3、将JSON数据转换为实体类的对象，将实体类对象的属性值转换为DataTable的行数据，完成JSON数据转换为DataTable的过程。

// 将JSON数据转换为实体类对象
    Student student = JsonConvert.DeserializeObject<Student>(json);
    // 将实体类对象的属性值转换为DataTable的行数据
    DataRow dr = dt.NewRow();
    foreach (PropertyInfo propertyInfo in propertyInfos)
    {
        
        dr[propertyInfo.Name] = propertyInfo.GetValue(student);
    }
    dt.Rows.Add(dr);

## \[WebMethod\]方法接收前端传入的JsonArray的方法 ##

**第一种方法：可以这样接收前端传入的jsonArray字符串到一个类的数组中，然后遍历该数组取值**  
这种方法需要创建PointConfig类

class PointConfig
            {
        
                public string ptcrossing {
         get; set; }
                public string ptcrossingId {
         get; set; }
                public string camId {
         get; set; }
                public string pointid {
         get; set; }
                public string ptdirection {
         get; set; }
                public string ptGoSet {
         get; set; }
                public string ptGoEn {
         get; set; }
                public string ptLeftSet {
         get; set; }
                public string ptLeftEn {
         get; set; }
                public string ptRightSet {
         get; set; }
                public string ptRightEn {
         get; set; }
                public string ptname {
         get; set; }
                public string ptmainX {
         get; set; }
                public string ptmainY {
         get; set; }
                public string ptsubX {
         get; set; }
                public string ptsubY {
         get; set; }
                public string ptframediffX {
         get; set; }
                public string ptframediffY {
         get; set; }
                public string ptgreenlightX {
         get; set; }
                public string ptgreenlightY {
         get; set; }
                public string ptredlightX {
         get; set; }
                public string ptredlightY {
         get; set; }
                public string ptmainvalid {
         get; set; }
                public string ptsubvalid {
         get; set; }
                public string ptframediffvalid {
         get; set; }
                public string ptqueuelengthvalid {
         get; set; }
                public string ptcheckmethod {
         get; set; }
                public string ptchanneltypeA {
         get; set; }
                public string ptchanneltypeB {
         get; set; }
                public string cameraName {
         get; set; }
                public string xgr {
         get; set; }
            }

[WebMethod]
        public static string checkPointConfigUpdateRecord(string pointObj)
        {
        
            PointConfig[] pointConfigs = JsonConvert.DeserializeObject<PointConfig[]>(pointObj);
           for (int i = 0; i < pointConfigs.Length; i++)
           {
        
                string crossingName_str = pointConfigs[i].ptcrossing.Trim();
                string crossingId_str = pointConfigs[i].ptcrossingId.Trim();
                string cameraId_str = pointConfigs[i].camId.Trim();
                string cameraName_str = pointConfigs[i].cameraName.Trim();
                string dir_str = pointConfigs[i].ptdirection.Trim();
                string i_go_str = pointConfigs[i].ptGoSet.Trim();
                string i_left_str = pointConfigs[i].ptLeftSet.Trim();
                string i_right_str = pointConfigs[i].ptRightSet.Trim();
                string laneName_str = pointConfigs[i].ptname.Trim();
                string main_x_str = pointConfigs[i].ptmainX.Trim();
                string main_y_str = pointConfigs[i].ptmainY.Trim();
                string mainPointValid_str = pointConfigs[i].ptmainvalid.Trim();
                string sub_x_str = pointConfigs[i].ptsubX.Trim();
                string sub_y_str = pointConfigs[i].ptsubY.Trim();
                string subPointValid_str = pointConfigs[i].ptsubvalid.Trim();
                string frame_x_str = pointConfigs[i].ptframediffX.Trim();
                string frame_y_str = pointConfigs[i].ptframediffY.Trim();
                string frameValid_str = pointConfigs[i].ptframediffvalid.Trim();
                string green_x_str = pointConfigs[i].ptgreenlightX.Trim();
                string green_y_str = pointConfigs[i].ptgreenlightY.Trim();
                string red_x_str = pointConfigs[i].ptredlightX.Trim();
                string red_y_str = pointConfigs[i].ptredlightY.Trim();
                string queueValid_str = pointConfigs[i].ptqueuelengthvalid.Trim();
                string calcMathod_str = pointConfigs[i].ptcheckmethod.Trim();
                string channelType_A_str = pointConfigs[i].ptchanneltypeA.Trim();
                string channelTypee_B_str = pointConfigs[i].ptchanneltypeB.Trim();
               string xgr_str = pointConfigs[i].xgr.Trim();
                string xgsj_str = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
                sb.Append("insert into 
    
    pointConfig(crossingName,crossingId,cameraId,cameraName,dir,i_go,i_left,i_right,laneName,main_x,main_y,mainPointValid,sub_x,sub_y,subPointValid,frame_x,frame_y,frameValid,green_x,green_y,red_x,red_y,queueValid,calcMathod,channelType_A,channelTypee_B,xgr,xgsj) " +
                    "values('" + crossingName_str + "','" + crossingId_str + "','" + cameraId_str + "','" + cameraName_str + "','" + dir_str + "','" + i_go_str + "','" + i_left_str + "','" +
                    i_right_str + "','" + laneName_str + "','" + main_x_str + "','" + main_y_str + "','" + mainPointValid_str + "','" + sub_x_str + "','" +
                    sub_y_str + "','" + subPointValid_str + "','" + frame_x_str + "','" + frame_y_str + "','" + frameValid_str + "','" + green_x_str + "','" + green_y_str + "','" + red_x_str + "','" + red_y_str + "','" + queueValid_str + "','" + calcMathod_str + "','" +
                    channelType_A_str + "','" + channelTypee_B_str + "','" + xgr_str + "','" + xgsj_str + "');");
                }
     }

**第二种方法：可以这样接收前端传入的jsonArray字符串到一个类的数组中，然后遍历该数组取值**

[WebMethod]
        public static string checkPointConfigUpdateRecord(string pointObj)
        {
        
            JavaScriptSerializer serializer = new JavaScriptSerializer();
    
            object[] jsonArray = (object[])serializer.DeserializeObject(pointObj);
            StringBuilder sb = new StringBuilder();
            if (jsonArray.Length<1)
            {
        
                return "{\"result\":false}";
            }
            for(int i = 0; i < jsonArray.Length; i++)
            {
        
                object pointConfig = jsonArray[i];
                // 然后将该元素转换为JSON对象
                string json1 = serializer.Serialize(pointConfig);
                Dictionary<string, object> json = (Dictionary<string, object>)serializer.DeserializeObject(json1);
    
                string crossingName_str = json["ptcrossing"].ToString().Trim();
                string crossingId_str = json["ptcrossingId"].ToString().Trim();
                string cameraId_str = json["camId"].ToString().Trim();
                string cameraName_str = json["cameraName"].ToString().Trim();
    
                string dir_str = json["ptdirection"].ToString().Trim();
                string i_go_str = json["ptGoSet"].ToString().Trim();
                string i_left_str = json["ptLeftSet"].ToString().Trim();
                string i_right_str = json["ptRightSet"].ToString().Trim();
                string laneName_str = json["ptname"].ToString().Trim();
    
                string main_x_str = json["ptmainX"].ToString().Trim();
                string main_y_str = json["ptmainY"].ToString().Trim();
                string mainPointValid_str = json["ptmainvalid"].ToString().Trim();
    
                string sub_x_str = json["ptsubX"].ToString().Trim();
                string sub_y_str = json["ptsubY"].ToString().Trim();
                string subPointValid_str = json["ptsubvalid"].ToString().Trim();
    
                string frame_x_str = json["ptframediffX"].ToString().Trim();
                string frame_y_str = json["ptframediffY"].ToString().Trim();
                string frameValid_str = json["ptframediffvalid"].ToString().Trim();
    
                string green_x_str = json["ptgreenlightX"].ToString().Trim();
                string green_y_str = json["ptgreenlightY"].ToString().Trim();
                string red_x_str = json["ptredlightX"].ToString().Trim();
                string red_y_str = json["ptredlightY"].ToString().Trim();
                string queueValid_str = json["ptqueuelengthvalid"].ToString().Trim();
    
    
    
                string calcMathod_str = json["ptcheckmethod"].ToString().Trim();
                string channelType_A_str = json["ptchanneltypeA"].ToString().Trim();
                string channelTypee_B_str = json["ptchanneltypeB"].ToString().Trim();
    
                string xgr_str = json["xgr"].ToString().Trim();
                string xgsj_str = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
    
    
            
                sb.Append("insert into pointConfig(crossingName,crossingId,cameraId,cameraName,dir,i_go,i_left,i_right,laneName,main_x,main_y,mainPointValid,sub_x,sub_y,subPointValid,frame_x,frame_y,frameValid,green_x,green_y,red_x,red_y,queueValid,calcMathod,channelType_A,channelTypee_B,xgr,xgsj) " +
                "values('" + crossingName_str + "','" + crossingId_str + "','" + cameraId_str + "','" + cameraName_str + "','" + dir_str + "','" + i_go_str + "','" + i_left_str + "','" +
                i_right_str + "','" + laneName_str + "','" + main_x_str + "','" + main_y_str + "','" + mainPointValid_str + "','" + sub_x_str + "','" +
                sub_y_str + "','" + subPointValid_str + "','" + frame_x_str + "','" + frame_y_str + "','" + frameValid_str + "','" + green_x_str + "','" + green_y_str + "','" + red_x_str + "','" + red_y_str + "','" + queueValid_str + "','" + calcMathod_str + "','" +
                channelType_A_str + "','" + channelTypee_B_str + "','" + xgr_str + "','" + xgsj_str + "');");
    
            }
    
            int jg = SqlHelper.ExecuteNoneQuery(sb.ToString(), new SqlParameter[] {
         });
    
            if (jg >= 0)
            {
        
                return "{\"result\":true}";
            }
            else
            {
        
    
                return "{\"result\":false}";
            }
      }

[https_blog.csdn.net_munangs_article_details_133950243]: https://blog.csdn.net/munangs/article/details/133950243