我們在很多時候，都要顯示TreeView或TreeGrid. 像jqGrid這種控件可以顯示TreeGrid.
但是jqGrid要想顯示正確，必須在傳遞給它數據之前，要將數據集按父子關係排序好。即：
ID|ParenetID|value
-------------------
1 |0 |....
2 |1 |....
3 |2 |....
4 |1 |....
1 private void button1_Click(object sender, EventArgs e) 2 { 3 DataSet ds = new DataSet(); 4 5 DataTable dt = new DataTable(); 6 7 dt.Columns.AddRange(new DataColumn[] 8 { 9 new DataColumn("SysID"), 10 new DataColumn("ParentSysID") , 11 new DataColumn("SomeValue") , 12 new DataColumn ("depth"), 13 new DataColumn ("seqNo",typeof(int)) 14 }) ; 15 16 DataRow dr = dt.NewRow(); 17 dr[0] = "1"; 18 dr[1] = "0"; 19 dr[2] = "value"; 20 dr[3] = "0"; 21 dr[4] = 1; 22 dt.Rows.Add(dr); 23 24 dr = dt.NewRow(); 25 dr[0] = "2"; 26 dr[1] = "1"; 27 dr[2] = "value"; 28 dr[3] = "1"; 29 dr[4] = 3; 30 dt.Rows.Add(dr); 31 32 dr = dt.NewRow(); 33 dr[0] = "3"; 34 dr[1] = "1"; 35 dr[2] = "value"; 36 dr[3] = "1"; 37 dr[4] = 2; 38 dt.Rows.Add(dr); 39 40 dr = dt.NewRow(); 41 dr[0] = "4"; 42 dr[1] = "2"; 43 dr[2] = "value"; 44 dr[3] = "2"; 45 dr[4] = 1; 46 dt.Rows.Add(dr); 47 48 dr = dt.NewRow(); 49 dr[0] = "5"; 50 dr[1] = "0"; 51 dr[2] = "value"; 52 dr[3] = "0"; 53 dr[4] = 10; 54 dt.Rows.Add(dr); 55 56 dr = dt.NewRow(); 57 dr[0] = "6"; 58 dr[1] = "0"; 59 dr[2] = "value"; 60 dr[3] = "0"; 61 dr[4] = 5; 62 dt.Rows.Add(dr); 63 64 dr = dt.NewRow(); 65 dr[0] = "7"; 66 dr[1] = "5"; 67 dr[2] = "value"; 68 dr[3] = "1"; 69 dr[4] = 1; 70 dt.Rows.Add(dr); 71 72 DataTable dt1 = dt.Clone(); 73 var d = dt.AsEnumerable().Min(m => m.Field<string>("depth")); 74 var a = dt.AsEnumerable().Select(m => { return new {sysid = m.Field<string>("sysID"),seqno = m.Field<int>("seqNo"), depth = m.Field<string>("depth") }; }).OrderBy(k => k.depth); 75 var c = a.First().depth; 76 var k1 = a.First().sysid; 77 78 RecrusionLook<string,string>(dt, dt1, d, default(string)); 79 80 } 81 82 private void RecrusionLook<T,K>(DataTable source, DataTable target, T depth, K parentSysID) 83 { 84 var result = from r in source.AsEnumerable() 85 where (r.Field<T>("depth").Equals(depth) || depth == null || depth.Equals(default(T))) && (r.Field<K>("ParentSysID").Equals(parentSysID) || parentSysID == null || parentSysID.Equals(default(K))) 86 orderby r.Field<int>("seqNo") 87 select r; 88 89 //result.Select(i => { target.ImportRow(i); RecrusionLook(source, target, "", i.Field<string>("sysID")); return; }); 90 foreach (var row in result) 91 { 92 target.ImportRow(row); 93 RecrusionLook<T, K>(source, target, default(T), row.Field<K>("sysID")); 94 } 95 96 }