2 // DataRowComparer_1.cs
5 // Atsushi Enomoto <atsushi@ximian.com>
7 // Copyright (C) 2008 Novell, Inc. http://www.novell.com
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
32 using System.Collections.Generic;
36 public sealed class DataRowComparer<TRow> : IEqualityComparer<TRow> where TRow : DataRow
38 static readonly DataRowComparer<TRow> default_instance = new DataRowComparer<TRow> ();
40 public static DataRowComparer<TRow> Default {
41 get { return default_instance; }
44 private DataRowComparer ()
48 // LAMESPEC: neither of the parameters throws ArgumentNullException if it's null
49 public bool Equals (TRow leftRow, TRow rightRow)
51 if (object.ReferenceEquals (leftRow, rightRow))
54 if (leftRow == null || rightRow == null)
57 int columnCount = leftRow.Table.Columns.Count;
58 if (columnCount != rightRow.Table.Columns.Count)
61 for (int i = 0; i < columnCount; i++)
62 if (!ColumnsEqual (leftRow [i], rightRow [i]))
67 bool ColumnsEqual (object leftCol, object rightCol)
69 if (object.ReferenceEquals (leftCol, rightCol))
72 if (leftCol == null || rightCol == null)
75 ValueType vt = leftCol as ValueType;
76 if (vt != null && vt.Equals (rightCol))
79 return leftCol.Equals (rightCol);
82 public int GetHashCode (TRow row)
85 throw new ArgumentNullException ("row");
87 DataTable table = row.Table;
89 throw new ArgumentException ("The source DataRow objects does not belong to a DataTable.");
91 DataColumnCollection columns = table.Columns;
92 int columnCount = columns.Count;
98 for (int i = 0; i < columnCount; i++) {
103 ret ^= o.GetHashCode ();