Code:
/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / whidbey / netfxsp / ndp / fx / src / Data / System / Data / ConstraintEnumerator.cs / 1 / ConstraintEnumerator.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data { using System; using System.Diagnostics; using System.Collections; using System.ComponentModel; ////// ConstraintEnumerator is an object for enumerating all constraints in a DataSet /// internal class ConstraintEnumerator { System.Collections.IEnumerator tables; System.Collections.IEnumerator constraints; Constraint currentObject; public ConstraintEnumerator(DataSet dataSet) { tables = (dataSet != null) ? dataSet.Tables.GetEnumerator() : null; currentObject = null; } public bool GetNext() { Constraint candidate; currentObject = null; while (tables != null) { if (constraints == null) { if (!tables.MoveNext()) { tables = null; return false; } constraints = ((DataTable)tables.Current).Constraints.GetEnumerator(); } if (!constraints.MoveNext()) { constraints = null; continue; } Debug.Assert(constraints.Current is Constraint, "ConstraintEnumerator, contains object which is not constraint"); candidate = (Constraint)constraints.Current; if (IsValidCandidate(candidate)) { currentObject = candidate; return true; } } return false; } public Constraint GetConstraint() { // If currentObject is null we are before first GetNext or after last GetNext--consumer is bad Debug.Assert (currentObject != null, "GetObject should never be called w/ null currentObject."); return currentObject; } protected virtual bool IsValidCandidate(Constraint constraint) { return true; } protected Constraint CurrentObject { get { return currentObject; } } } internal class ForeignKeyConstraintEnumerator : ConstraintEnumerator { public ForeignKeyConstraintEnumerator(DataSet dataSet) : base(dataSet) { } protected override bool IsValidCandidate(Constraint constraint) { return(constraint is ForeignKeyConstraint); } public ForeignKeyConstraint GetForeignKeyConstraint() { // If CurrentObject is null we are before first GetNext or after last GetNext--consumer is bad Debug.Assert (CurrentObject != null, "GetObject should never be called w/ null currentObject."); return(ForeignKeyConstraint)CurrentObject; } } internal sealed class ChildForeignKeyConstraintEnumerator : ForeignKeyConstraintEnumerator { // this is the table to do comparisons against DataTable table; public ChildForeignKeyConstraintEnumerator(DataSet dataSet, DataTable inTable) : base(dataSet) { this.table = inTable; } protected override bool IsValidCandidate(Constraint constraint) { return((constraint is ForeignKeyConstraint) && (((ForeignKeyConstraint)constraint).Table == table)); } } internal sealed class ParentForeignKeyConstraintEnumerator : ForeignKeyConstraintEnumerator { // this is the table to do comparisons against DataTable table; public ParentForeignKeyConstraintEnumerator(DataSet dataSet, DataTable inTable) : base(dataSet) { this.table = inTable; } protected override bool IsValidCandidate(Constraint constraint) { return((constraint is ForeignKeyConstraint) && (((ForeignKeyConstraint)constraint).RelatedTable == table)); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data { using System; using System.Diagnostics; using System.Collections; using System.ComponentModel; ////// ConstraintEnumerator is an object for enumerating all constraints in a DataSet /// internal class ConstraintEnumerator { System.Collections.IEnumerator tables; System.Collections.IEnumerator constraints; Constraint currentObject; public ConstraintEnumerator(DataSet dataSet) { tables = (dataSet != null) ? dataSet.Tables.GetEnumerator() : null; currentObject = null; } public bool GetNext() { Constraint candidate; currentObject = null; while (tables != null) { if (constraints == null) { if (!tables.MoveNext()) { tables = null; return false; } constraints = ((DataTable)tables.Current).Constraints.GetEnumerator(); } if (!constraints.MoveNext()) { constraints = null; continue; } Debug.Assert(constraints.Current is Constraint, "ConstraintEnumerator, contains object which is not constraint"); candidate = (Constraint)constraints.Current; if (IsValidCandidate(candidate)) { currentObject = candidate; return true; } } return false; } public Constraint GetConstraint() { // If currentObject is null we are before first GetNext or after last GetNext--consumer is bad Debug.Assert (currentObject != null, "GetObject should never be called w/ null currentObject."); return currentObject; } protected virtual bool IsValidCandidate(Constraint constraint) { return true; } protected Constraint CurrentObject { get { return currentObject; } } } internal class ForeignKeyConstraintEnumerator : ConstraintEnumerator { public ForeignKeyConstraintEnumerator(DataSet dataSet) : base(dataSet) { } protected override bool IsValidCandidate(Constraint constraint) { return(constraint is ForeignKeyConstraint); } public ForeignKeyConstraint GetForeignKeyConstraint() { // If CurrentObject is null we are before first GetNext or after last GetNext--consumer is bad Debug.Assert (CurrentObject != null, "GetObject should never be called w/ null currentObject."); return(ForeignKeyConstraint)CurrentObject; } } internal sealed class ChildForeignKeyConstraintEnumerator : ForeignKeyConstraintEnumerator { // this is the table to do comparisons against DataTable table; public ChildForeignKeyConstraintEnumerator(DataSet dataSet, DataTable inTable) : base(dataSet) { this.table = inTable; } protected override bool IsValidCandidate(Constraint constraint) { return((constraint is ForeignKeyConstraint) && (((ForeignKeyConstraint)constraint).Table == table)); } } internal sealed class ParentForeignKeyConstraintEnumerator : ForeignKeyConstraintEnumerator { // this is the table to do comparisons against DataTable table; public ParentForeignKeyConstraintEnumerator(DataSet dataSet, DataTable inTable) : base(dataSet) { this.table = inTable; } protected override bool IsValidCandidate(Constraint constraint) { return((constraint is ForeignKeyConstraint) && (((ForeignKeyConstraint)constraint).RelatedTable == table)); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- QueryExecutionOption.cs
- validation.cs
- PopOutPanel.cs
- CacheVirtualItemsEvent.cs
- FontWeightConverter.cs
- LicenseContext.cs
- Delegate.cs
- SpeechEvent.cs
- ZoomPercentageConverter.cs
- ReliabilityContractAttribute.cs
- Mouse.cs
- HttpResponseBase.cs
- ListViewDesigner.cs
- Console.cs
- util.cs
- Parameter.cs
- FormatControl.cs
- Application.cs
- ProxyGenerator.cs
- LineInfo.cs
- DesignerActionUIStateChangeEventArgs.cs
- BinaryFormatterWriter.cs
- ClientConfigurationSystem.cs
- RuleRef.cs
- SafeIUnknown.cs
- datacache.cs
- XmlDictionaryReaderQuotas.cs
- FlowDocumentReaderAutomationPeer.cs
- UserControlParser.cs
- CustomErrorsSection.cs
- SchemaTableOptionalColumn.cs
- ObjectView.cs
- PolyQuadraticBezierSegment.cs
- FreezableDefaultValueFactory.cs
- Themes.cs
- BidPrivateBase.cs
- Grammar.cs
- BinaryVersion.cs
- DbConnectionHelper.cs
- SerializerDescriptor.cs
- ComponentEditorPage.cs
- WebResourceUtil.cs
- externdll.cs
- ServiceContractGenerator.cs
- BuildProviderInstallComponent.cs
- DbProviderSpecificTypePropertyAttribute.cs
- OdbcFactory.cs
- UnsafeNativeMethodsMilCoreApi.cs
- AccessDataSourceView.cs
- SqlWebEventProvider.cs
- TextTreeFixupNode.cs
- ParentQuery.cs
- OdbcInfoMessageEvent.cs
- SchemaNamespaceManager.cs
- SqlOuterApplyReducer.cs
- GridViewRowCollection.cs
- LocalBuilder.cs
- AsymmetricKeyExchangeDeformatter.cs
- TypeDependencyAttribute.cs
- RoleServiceManager.cs
- RemotingServices.cs
- EncoderExceptionFallback.cs
- ViewKeyConstraint.cs
- DomNameTable.cs
- URIFormatException.cs
- DrawingContextWalker.cs
- LoginStatusDesigner.cs
- HttpCapabilitiesEvaluator.cs
- MonthChangedEventArgs.cs
- PerformanceCountersBase.cs
- Attributes.cs
- OleDbInfoMessageEvent.cs
- _NegoStream.cs
- CheckBoxBaseAdapter.cs
- MetadataPropertyCollection.cs
- XmlReflectionMember.cs
- BindingGroup.cs
- GridPattern.cs
- CommonDialog.cs
- TableAdapterManagerNameHandler.cs
- ObjectTokenCategory.cs
- Internal.cs
- BooleanFunctions.cs
- TreeViewImageIndexConverter.cs
- SoapMessage.cs
- ContainerFilterService.cs
- TreeBuilderXamlTranslator.cs
- DbXmlEnabledProviderManifest.cs
- AutoGeneratedFieldProperties.cs
- StylusCaptureWithinProperty.cs
- NetPipeSection.cs
- RuntimeConfigurationRecord.cs
- MarkupCompilePass1.cs
- IUnknownConstantAttribute.cs
- TraceListeners.cs
- AuthenticateEventArgs.cs
- IfAction.cs
- SvcMapFile.cs
- DataGridViewAccessibleObject.cs
- FloatUtil.cs