“System.ArgumentNullException”类型的第一次机会异常在 mscorlib.dll 中发生 其他信息: 值不能为 null

1  #region//向PFXJ表中插入Ln项集，并返回Ln,参数为Ln的后选项(Cn)
 2         public string[,] LnInsertToPFXJ(string[,] L, int minSupport)
 3         {
 4             int hang = L.GetLength(0);
 5             int lie = L.GetLength(1);
 6 
 7             string[,] Cn = new string[hang, lie];
 8             int max = 0;//得到的Ln的实际行数            
 9 
10             for (int i = 0; i < hang; i++)
11             {
12                 StreamReader sr = new StreamReader("My.txt", Encoding.GetEncoding("gb2312"));
13                 string line = string.Empty;
14                 int zhiChiPinDu = 0;
15                 int num = 0;//用来判断是否二维数组的行中元素满足条件
16                 string strLn = string.Empty;//存候选项集元素
17                 while ((line = sr.ReadLine()) != null)
18                 {
19                     for(
20                         
21                         int j = 0; j < lie; j++)
22                     {
23                         if (line.Contains(L[i, j]))/*此处抛出异常，对应堆栈中的中的> HouseSale.exe!HouseSale.Apriori.LnInsertToPFXJ(string[,] L, int minSupport) 行 294 C#*/
24                         {
25                             int lineLen = line.Length;
26                             if (L[i, j].Length == 3 && lineLen > 3 && (line.Substring(lineLen - 4, 1) == "I"))
27                             {
28                                 int len = line.IndexOf(L[i, j]);
29                                 string str = line.Substring(len + 3, 1);
30                                 if (str == "I")
31                                 {
32                                     num += 1;
33                                 }
34                             }
35                             else
36                             {
37                                 num += 1;
38                             }
39                         }
40                     }
41                     if (num == lie)
42                     {
43                         zhiChiPinDu += 1;
44                     }
45                     num = 0;
46                 }
47                 sr.Close();
48                 if (zhiChiPinDu >= minSupport)
49                 {
50                     for (int j = 0; j < lie; j++)
51                     {
52                         strLn += (L[i, j] + ",");
53 
54                     }
55                     strLn = strLn.Substring(0, strLn.Length - 1);
56                     string sql = "insert into PFXJ values('" + lie.ToString() + "','" + strLn + "','" + zhiChiPinDu.ToString() + "')";
57                     ErpApplication erp = new ErpApplication();
58 
59                     erp.Esql(sql);
60 
61 
62                     max += 1;
63 
64                     string myStr = string.Empty;
65                     for (int j = 0; j < lie; j++)
66                     {
67                         if (strLn.Contains(","))
68                         {
69                             int dLen = strLn.IndexOf(",");
70                             myStr = strLn.Substring(0, dLen);
71 
72                             Cn[max - 1, j] = myStr;
73                             strLn = strLn.Substring(dLen + 1, strLn.Length - dLen - 1);
74                         }
75                         else
76                         {
77                             Cn[max - 1, j] = strLn;
78                         }
79                     }
80                 }
81 
82                 strLn = string.Empty;
83             }

调用堆栈如下：

[外部代码]

> HouseSale.exe!HouseSale.Apriori.LnInsertToPFXJ(string[,] L, int minSupport) 行 294 C#

HouseSale.exe!HouseSale.Apriori.MyApriori(string[] Id, int minSupport) 行 169 C#

HouseSale.exe!HouseSale.DigDataForm.button5_Click(object sender, System.EventArgs e) 行 97 C#

[外部代码]

HouseSale.exe!HouseSale.ChooseForm.button5_Click(object sender, System.EventArgs e) 行 205 C#

[外部代码]

HouseSale.exe!HouseSale.Program.Main() 行 21 C#

[外部代码]