c# - 数字输出全为零？

Question

我想读入一个包含人口普查数据的文件。根据这些数据，我需要输出给定地区的人口数量以及特定年龄段的人口数量。

问题是我的输出显示全为零，除了“18 岁以下”行显示 100。作为引用，正在读取的文件有 100 人和 22 个地区。

这是我的代码:

class Program
{
    static void Main(string[] args)
    {
        FileStream fStream = new FileStream("censusdata.txt", FileMode.Open, FileAccess.Read);
        StreamReader inFile = new StreamReader(fStream);

        string input = "";
        int age = 0;
        int district = 0;
        const int AGE = 5;
        const int DISTRICT = 22;
        string[] fields;
        bool ageBool = true;
        bool distBool = true;
        int[] ageCount = new int[AGE];
        int[] ageRange = new int[AGE] { 0, 18, 30, 45, 64 };
        int[] districtCount = new int[DISTRICT];
        int[] districtRange = new int[DISTRICT];

        input = inFile.ReadLine();
        while(input != null)
        {
            fields = input.Split(',');
            input = inFile.ReadLine();

            if (ageBool)
            {
                validDataAge(fields, input, age, ageBool);
                getValuePerAge(age, ageCount, ageRange);
            }
            else
                Console.WriteLine("error");

            if (distBool)
            {
                validDataDistrict(fields, input, district, distBool);
                getValuePerDistrict(district, districtCount, districtRange);
            }
            else
                Console.WriteLine("error");
        }
        displayOutput(districtCount, ageCount);
    }

    static bool validDataAge(string[] fieldsArray, string inputData, int a, bool age)
    {
        if (int.TryParse(fieldsArray[0], out a))
        {
            age = true;
            return age;
        }
        else
        {
            age = false;
            return age;
        }
    }

    static bool validDataDistrict(string[] fieldsArray, string inputData, int d, bool district)
    {
        if (int.TryParse(fieldsArray[3], out d))
        {
            district = true;
            return district;
        }
        else
        {
            district = false;
            return district;
        }
    }

    static void getValuePerDistrict(int d, int[] districtCountArray, int[] districtRangeArray)
    {
        for (int x = 1; x <= districtRangeArray.Length; x++)
        {
            if (x == d)
                districtCountArray[x]++;
        }

    }

    static void getValuePerAge(int a, int[] ageCountArray, int[] ageRangeArray)
    {
        int index = ageRangeArray.Length - 1;
        while(a < ageRangeArray[index])
            index--;


        ageCountArray[index]++;
    }

    public static void displayOutput(int[] districtCountArray, int[] ageCountArray)
    {
        for (int x = 0; x < districtCountArray.Length; x++)
        {
            Console.WriteLine("District " + (x + 1) + ": Population = " + districtCountArray[x]);
        }

        Console.WriteLine("");
        Console.WriteLine("");
        Console.WriteLine("");
        Console.WriteLine("");


        Console.WriteLine("Age Under 18: Population = " + ageCountArray[0]);
        Console.WriteLine("Ages 18-30: Population = " + ageCountArray[1]);
        Console.WriteLine("Ages 31-45: Population = " + ageCountArray[2]);
        Console.WriteLine("Ages 46-64: Population = " + ageCountArray[3]);
        Console.WriteLine("65 & Over: Population = " + ageCountArray[4]);

    }
}

这是输出:

District 1: Population = 0District 2: Population = 0District 3: Population = 0District 4: Population = 0District 5: Population = 0District 6: Population = 0District 7: Population = 0District 8: Population = 0District 9: Population = 0District 10: Population = 0District 11: Population = 0District 12: Population = 0District 13: Population = 0District 14: Population = 0District 15: Population = 0District 16: Population = 0District 17: Population = 0District 18: Population = 0District 19: Population = 0District 20: Population = 0District 21: Population = 0District 22: Population = 0Age Under 18: Population = 100Ages 18-30: Population = 0Ages 31-45: Population = 0Ages 46-64: Population = 065 & Over: Population = 0Press any key to continue . . .

Answer 1

您需要在 validDataAge 方法中将 int a 设为 out int a:

static bool validDataAge(string[] fieldsArray, string inputData, out int a, bool age)
{
    if (int.TryParse(fieldsArray[0], out a))
    {
        age = true;
        return age;
    }
    else
    {
        age = false;
        return age;
    }
}

但是，作为进一步的建议，该方法可以写成:

static bool validDataAge(string inputData, out int a)
{
    return int.TryParse(inputData, out a);
}

但是，validDataAge 与 int.TryParse 的功能基本相同，因此您可以完全删除 validDataAge。