linq一般用法

最一般的用法

 1             var rows =
 2                    from c in dataTrue.AsEnumerable()
 3                    from t in dataPre.AsEnumerable()
 4                    where t[0].ToString().StartsWith(c[1].ToString())
 5                    select new
 6                    {
 7                        ID = c[0],
 8                        dayTime = this.StrDateConvertDateToString(c[1].ToString()),
 9
10                        value = c[2],
11                        pre1 = t[1],
12                        pre2 = t[2],
13                        pre3 = t[3],
14
15                        valueu = c[3],
16                        pre1u = t[4],
17                        pre2u = t[5],
18                        pre3u = t[6],
19
20                        valuem = c[4],
21                        pre1m = t[7],
22                        pre2m = t[8],
23                        pre3m = t[9],
24
25                        valuec = c[5],
26                        pre1c = t[10],
27                        pre2c = t[11],
28                        pre3c = t[12]
29                    };
30             rows = rows.Distinct();
31
32            // rows = rows.Distinct();
33
34
35             DataTable dt = new DataTable();
36             dt.Columns.Add("ID", typeof(string));
37             dt.Columns.Add("dayTime", typeof(string));
38             dt.Columns.Add("value", typeof(string));
39             dt.Columns.Add("pre1", typeof(string));
40             dt.Columns.Add("pre2", typeof(string));
41             dt.Columns.Add("pre3", typeof(string));
42
43
44             dt.Columns.Add("valueu", typeof(string));
45             dt.Columns.Add("pre1u", typeof(string));
46             dt.Columns.Add("pre2u", typeof(string));
47             dt.Columns.Add("pre3u", typeof(string));
48
49
50             dt.Columns.Add("valuem", typeof(string));
51             dt.Columns.Add("pre1m", typeof(string));
52             dt.Columns.Add("pre2m", typeof(string));
53             dt.Columns.Add("pre3m", typeof(string));
54
55
56
57             dt.Columns.Add("valuec", typeof(string));
58             dt.Columns.Add("pre1c", typeof(string));
59             dt.Columns.Add("pre2c", typeof(string));
60             dt.Columns.Add("pre3c", typeof(string));
61             //插入id
62             rows.ToList().ForEach(kv => dt.Rows.Add(kv.ID, kv.dayTime, kv.value, kv.pre1, kv.pre2, kv.pre3, kv.valueu, kv.pre1u, kv.pre2u, kv.pre3u, kv.valuem, kv.pre1m, kv.pre2m, kv.pre3m, kv.valuec, kv.pre1c, kv.pre2c, kv.pre3c));
63
64
65             this.dg1.DataContext = null;
66             this.dg1.DataContext = dt;
67             this.dg1.Items.Refresh();