如果字段存在，C# 计数

Question

下面是一个执行 API 调用的脚本，它检索一些 ReportID（从数据库表中），将它们传递给一个单独运行它们的方法，最后查看每个是否包含字段 Name_First。

我需要帮助的是创建一个计数，它会告诉我有多少报告包含字段 Name_First，有多少不包含字段，以及在所有报告中包含字段 Name_First 的百分比是多少。

目前，该脚本会查询两个 ReportID (12300,12301) 进行测试。一份报告中包含字段 Name_First，而另一份则没有。从我编写的 foreach 循环中，我的目标是计算每次有空值和每次没有空值时，得到一个总数，然后将非空值除以两者的总和。但是，当我运行此脚本时，控制台位于

                Console.WriteLine(total);
                Console.WriteLine(total_noFirstName);
                Console.WriteLine(total_FirstName);

返回值 0、0 和 0。我认为我在这里遇到了范围问题，但我不太确定。如果我能得到一些帮助来解决这个问题，我将非常感激。

谢谢！

---

using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;

namespace NameFirstSearch
{
   class Program
{

    static void Main(string[] args)
    {
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;

        const string username = "Username";
        const string password = "Password";



        const string baseUrl = "https://test.com/rest/services/";


        const string queryString = "query?q=Select * From Report Where ReportID in (12300,12301)";
        const string queryNameFirst = "getreport/";

        var client = new HttpClient();

        client.BaseAddress = new Uri(baseUrl);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        var auth = Convert.ToBase64String(Encoding.Default.GetBytes(username + ":" + password));
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", auth);

        //GetReports(client, queryString).Wait();
        var  reportsList = GetReports(client, queryString).Result;
        GetNameFirst(client, queryNameFirst, reportsList).Wait();

        Console.ReadLine();

    }



    static async Task<List<Properties>> GetReports(HttpClient client, string queryString)
    {

        List<Properties> result = new List<Properties>();

        var response = await client.GetAsync(queryString);

        // Check for a successfull result
        if (response.IsSuccessStatusCode)
        {
            var json = await response.Content.ReadAsStringAsync();

            result = JsonConvert.DeserializeObject<List<Properties>>(json);
        }
        else
        {
            // Error code returned
            Console.WriteLine("No records found on first method.");
        }

        return result;

    }


    static async Task GetNameFirst(HttpClient client, string queryNameFirst, List<Properties> results)
    {
        string reportType = ".json";

        foreach (var item in results)
        {
            var output = await client.GetAsync(queryNameFirst + item.ReportID + reportType);


            if (output.IsSuccessStatusCode)
            {
                var allText = await output.Content.ReadAsStringAsync();

                var fields = JsonConvert.DeserializeObject<List<FirstName>>(allText);

                var test = JsonConvert.SerializeObject(fields);

                Console.WriteLine(test);

                int total_FirstName = 0;
                int total_noFirstName = 0;
                int total = total_FirstName + total_noFirstName;
                foreach (var split in fields)
                {

                    if (split.Name_First != null)
                    {
                        total_FirstName++;

                    }
                    else if (split.Name_First == null)
                    {

                        total_noFirstName++;

                    }

                }
                Console.WriteLine(total);
                Console.WriteLine(total_noFirstName);
                Console.WriteLine(total_FirstName);

            }
            else
            {
                // Error code returned
                Console.WriteLine("No records found on second method.");
            }

        }

    }



}
}

---

类属性

int ReportID {get; set;}

---

类名

string Name_First {get; set;}

---

Console.WriteLine(test) 处的结果；

 [{"Name_First":"Mario"}]
 [{"Name_First":null}]

---

Console.WriteLine(allText);的结果

 [{"Name_First":"Mario","Entry_ID":"72313"}]
 [{"Name_Last":"Rincon Recio","Entry_ID":"72313"}]

Answer 1

如果你想在一个循环中保持计数，你需要在循环之外声明计数器变量，否则它们会被重新初始化。使用问题中的数据，相关循环应如下所示：

    List<string> allTexts = new List<string>
    { @"[{""Name_First"":""Mario"",""Entry_ID"":""72313""}]",
      @"[{""Name_Last"":""Rincon Recio"",""Entry_ID"":""72313""}]" };

    int total_FirstName = 0;
    int total_noFirstName = 0;

    foreach(var allText in allTexts)
    {
        var fields = JsonConvert.DeserializeObject<List<FirstName>>(allText);
        var test = JsonConvert.SerializeObject(fields);
        Console.WriteLine(test);

        foreach (var split in fields)
        {
            if (split.Name_First != null)
            {
                total_FirstName++;
            }
            else
            {
                total_noFirstName++;
            }
        }
    }
    int total = total_FirstName + total_noFirstName;
    Console.WriteLine(total);
    Console.WriteLine(total_noFirstName);
    Console.WriteLine(total_FirstName);

输出：

 [{"Name_First":"Mario"}]
 [{"Name_First":null}]
 2
 1
 1