mcs/class/referencesource/System.Data/System/Data/RelationshipConverter.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="RelationshipConverter.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 // <owner current="true" primary="false">Microsoft</owner>
   7 // <owner current="false" primary="false">Microsoft</owner>
   8 //------------------------------------------------------------------------------
   9
  10 namespace System.Data {
  11     using System;
  12     using System.ComponentModel;
  13     using System.ComponentModel.Design.Serialization;
  14     using System.Globalization;
  15
  16     sealed internal class RelationshipConverter : ExpandableObjectConverter {
  17
  18         // converter classes should have public ctor
  19         public RelationshipConverter() {
  20         }
  21
  22
  23         /// <devdoc>
  24         ///    <para>Gets a value indicating whether this converter can
  25         ///       convert an object to the given destination type using the context.</para>
  26         /// </devdoc>
  27         public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
  28             if (destinationType == typeof(InstanceDescriptor)) {
  29                 return true;
  30             }
  31             return base.CanConvertTo(context, destinationType);
  32         }
  33
  34         /// <devdoc>
  35         ///      Converts the given object to another type.  The most common types to convert
  36         ///      are to and from a string object.  The default implementation will make a call
  37         ///      to ToString on the object if the object is valid and if the destination
  38         ///      type is string.  If this cannot convert to the desitnation type, this will
  39         ///      throw a NotSupportedException.
  40         /// </devdoc>
  41         public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
  42             if (destinationType == null) {
  43                 throw new ArgumentNullException("destinationType");
  44             }
  45
  46             System.Reflection.ConstructorInfo ctor = null;
  47             object[] values = null;
  48
  49             if (destinationType == typeof(InstanceDescriptor) && value is DataRelation) {
  50                 DataRelation rel = (DataRelation) value;
  51                 DataTable parentTable = rel.ParentKey.Table;
  52                 DataTable childTable = rel.ChildKey.Table;
  53
  54                 if (System.Data.Common.ADP.IsEmpty(parentTable.Namespace) && System.Data.Common.ADP.IsEmpty(childTable.Namespace)) {
  55                     ctor = typeof(DataRelation).GetConstructor(new Type[] { typeof(string) /*relationName*/, typeof(string) /*parentTableName*/, typeof(string) /*childTableName */,
  56                         typeof(string[]) /*parentColumnNames */, typeof(string[])  /*childColumnNames*/, typeof(bool) /*nested*/ } );
  57
  58                     values = new object[] { rel.RelationName, rel.ParentKey.Table.TableName, rel.ChildKey.Table.TableName,rel.ParentColumnNames, rel.ChildColumnNames, rel.Nested };
  59                 }
  60                 else {
  61                     ctor = typeof(DataRelation).GetConstructor(new Type[] { typeof(string)/*relationName*/, typeof(string)/*parentTableName*/, typeof(string)/*parentTableNamespace*/,
  62                         typeof(string)/*childTableName */, typeof(string)/*childTableNamespace */,
  63                         typeof(string[])/*parentColumnNames */, typeof(string[]) /*childColumnNames*/, typeof(bool) /*nested*/} );
  64
  65                     values = new object[] { rel.RelationName, rel.ParentKey.Table.TableName, rel.ParentKey.Table.Namespace, rel.ChildKey.Table.TableName,
  66                         rel.ChildKey.Table.Namespace, rel.ParentColumnNames, rel.ChildColumnNames, rel.Nested };
  67                 }
  68
  69                 return new InstanceDescriptor(ctor, values);
  70             }
  71
  72             return base.ConvertTo(context, culture, value, destinationType);
  73         }
  74     }
  75 }
  76