Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System/compmod/system/componentmodel/DataObjectFieldAttribute.cs

@@ -0,0 +1,80 @@
+//------------------------------------------------------------------------------
+// <copyright file="DataObjectFieldAttribute.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.ComponentModel {
+
+    using System;
+    using System.Security.Permissions;
+
+    /// <devdoc>
+    /// Represents a field of a DataObject. Use this attribute on a field to indicate
+    /// properties such as primary key, identity, nullability, and length.
+    /// </devdoc>
+    [AttributeUsage(AttributeTargets.Property)]
+    public sealed class DataObjectFieldAttribute : Attribute {
+        private bool _primaryKey;
+        private bool _isIdentity;
+        private bool _isNullable;
+        private int _length;
+
+        public DataObjectFieldAttribute(bool primaryKey) : this(primaryKey, false, false, -1) {
+        }
+
+        public DataObjectFieldAttribute(bool primaryKey, bool isIdentity) : this(primaryKey, isIdentity, false, -1) {
+        }
+
+        public DataObjectFieldAttribute(bool primaryKey, bool isIdentity, bool isNullable) : this(primaryKey, isIdentity, isNullable, -1){
+        }
+
+        public DataObjectFieldAttribute(bool primaryKey, bool isIdentity, bool isNullable, int length) {
+            _primaryKey = primaryKey;
+            _isIdentity = isIdentity;
+            _isNullable = isNullable;
+            _length = length;
+        }
+
+        public bool IsIdentity {
+            get {
+                return _isIdentity;
+            }
+        }
+
+        public bool IsNullable {
+            get {
+                return _isNullable;
+            }
+        }
+
+        public int Length {
+            get {
+                return _length;
+            }
+        }
+
+        public bool PrimaryKey {
+            get {
+                return _primaryKey;
+            }
+        }
+
+        public override bool Equals(object obj) {
+            if (obj == this) {
+                return true;
+            }
+
+            DataObjectFieldAttribute other = obj as DataObjectFieldAttribute;
+            return (other != null) &&
+                (other.IsIdentity == IsIdentity) &&
+                (other.IsNullable == IsNullable) &&
+                (other.Length == Length) &&
+                (other.PrimaryKey == PrimaryKey);
+        }
+
+        public override int GetHashCode() {
+            return base.GetHashCode();
+        }
+    }
+}