Question

我想读取小数值并使用它做出决定。如果值大于0.75则存储一个案例否则不存在。我正在划分4/5，答案是0.8，但变量是存储0而不是0.8。

班级代码如下：

    float value;

    List<crime> finalList = new List<crime>();
    Dictionary<int,float> finalDictionary = new Dictionary<int,float>(); 


    public float matching()
    {
        string crimeType = null;
        string keys = null;
        List<crime> keywordsFromOldCrimes = new List<crime>();
        List<String> keywordsFromCrimes = new List<string>();

        List<string> commonWords = new List<string>();
        SqlConnection conn = new SqlConnection(@"Data Source=DELL\SQLEXPRESS;initial catalog=CDMIS;integrated security=True;MultipleActiveResultSets=true;");
        SqlCommand commd = new SqlCommand("select * from crime where id=0 ", conn);
        SqlCommand commd1 = new SqlCommand("select * from crime", conn);
        SqlCommand commd2 = new SqlCommand("select crime.id , crime.crimeType, crime.keywords from crime inner join FIR on crime.FIRid= FIR.id where FIR.incidentDate in (select from FIR where datepart(yy, incidentDate)>2015)", conn);
        SqlCommand com3 = new SqlCommand("select * from crime where crimedate >= '2015-01-01'",conn);
        SqlDataReader read1;
        SqlDataReader read2;
        try
        {
            conn.Open();
            read1 = commd.ExecuteReader();
            while (read1.Read())
            {
                crimeType = read1.GetString(read1.GetOrdinal("crimeType"));
                keys = read1.GetString(read1.GetOrdinal("keywords"));
            }
        }
        catch (Exception exp)
        {
            throw exp;
        }

        read1.Close();
        List<string> keywords = keys.Split(',').ToList();

       // read2 = commd2.ExecuteReader();
        //while (read2.Read())
        //{
        //    keywords.Add(new crime()
        //    {
        //        id = read2.GetInt32(read2.GetOrdinal("id")),
        //        keywords = read2.GetString(read2.GetOrdinal("keywords")),
        //        crimeType = read2.GetString(read2.GetOrdinal("crimeType"))
        //    });
        //}
        //read2.Close();
        //foreach (var word in keyword)
        //{
        //    if (word.keywords == keys)
        //    {

        //    }
        //}
        read1 = com3.ExecuteReader();
        while (read1.Read())
        {
            keywordsFromOldCrimes.Add(new crime()
            {
                id = read1.GetInt32(read1.GetOrdinal("id")),
                caseStatus = read1.GetString(read1.GetOrdinal("caseStatus")),
                crimeType = read1.GetString(read1.GetOrdinal("crimeType")),
                details = read1.GetString(read1.GetOrdinal("details")),
                keywords = read1.GetString(read1.GetOrdinal("keywords")),

            });
        }

        foreach (var crime in keywordsFromOldCrimes)
        {
             keywordsFromCrimes = crime.keywords.Split(',').ToList();
             commonWords = keywords.Intersect(keywordsFromCrimes).ToList();
             value = commonWords.Count() / keywords.Count();
             Console.Write(value);
             if (value > 0.75)
             {
                 finalDictionary.Add(crime.id, value);
             }
             else
             {
                 Console.Write("nothing common");
             }
        }

        return (value);
    }

}

问题在于以下部分：

    foreach (var crime in keywordsFromOldCrimes)
    {
         keywordsFromCrimes = crime.keywords.Split(',').ToList();
         commonWords = keywords.Intersect(keywordsFromCrimes).ToList();
         value = commonWords.Count() / keywords.Count();
         Console.Write(value);
         if (value > 0.75)
         {
             finalDictionary.Add(crime.id, value);
         }
         else
         {
             Console.Write("nothing common");
         }
    }

根据我的数据库中的数据，commonWords.count（）= 4的值和keywords.count（）= 5的值，因此变量“value”中的答案应为“0.8”，但它为“0”。

Answer 1

这部分

commonWords.Count() / keywords.Count()

是整数除法，需要将其转换为浮动才能使其正常工作

commonWords.Count() / (float) keywords.Count()

在c＃代码中读取十进制值时遇到问题

1 个答案: