Code:
/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / 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.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- UserInitiatedNavigationPermission.cs
- SoapReflectionImporter.cs
- BufferedGraphicsContext.cs
- ObjectTag.cs
- XmlSchemaGroupRef.cs
- SortKey.cs
- Attributes.cs
- HostSecurityManager.cs
- XslVisitor.cs
- StyleSheetDesigner.cs
- TemplateField.cs
- StringFreezingAttribute.cs
- TraceLog.cs
- InstanceNameConverter.cs
- DataTableClearEvent.cs
- SchemaEntity.cs
- ListControl.cs
- IfAction.cs
- DesignerActionService.cs
- PiiTraceSource.cs
- UIElement.cs
- Context.cs
- RangeValueProviderWrapper.cs
- DrawingAttributes.cs
- UnmanagedMemoryStreamWrapper.cs
- MergablePropertyAttribute.cs
- CachedCompositeFamily.cs
- ContextMenuStripGroup.cs
- EventTask.cs
- BulletedListEventArgs.cs
- SequentialOutput.cs
- OutputCacheProfileCollection.cs
- CacheHelper.cs
- CodeExpressionCollection.cs
- ProjectedSlot.cs
- XmlEventCache.cs
- Typeface.cs
- X509Certificate.cs
- MetadataArtifactLoaderCompositeFile.cs
- CookielessHelper.cs
- BindingRestrictions.cs
- QilPatternVisitor.cs
- TimelineGroup.cs
- AssemblySettingAttributes.cs
- CqlParser.cs
- TouchEventArgs.cs
- ActivationServices.cs
- ImpersonationOption.cs
- DBSqlParserColumn.cs
- MemoryFailPoint.cs
- DateTimeParse.cs
- MinMaxParagraphWidth.cs
- Schema.cs
- HttpListenerElement.cs
- DrawingVisual.cs
- TokenBasedSetEnumerator.cs
- IdnMapping.cs
- ExceptionValidationRule.cs
- SmtpReplyReader.cs
- DelayedRegex.cs
- TextEditorCharacters.cs
- Point3D.cs
- LinkArea.cs
- DateTimeConverter2.cs
- DataGridViewToolTip.cs
- NativeMethods.cs
- NativeCppClassAttribute.cs
- DbDataRecord.cs
- RegexCompilationInfo.cs
- ArrayExtension.cs
- XmlSchemaValidator.cs
- PasswordBox.cs
- HtmlGenericControl.cs
- BulletDecorator.cs
- WebControlToolBoxItem.cs
- DictionaryEntry.cs
- TemplateKeyConverter.cs
- ArgumentValue.cs
- Expr.cs
- RuntimeEnvironment.cs
- SecurityHelper.cs
- TransformerTypeCollection.cs
- StaticFileHandler.cs
- TableMethodGenerator.cs
- ClientApiGenerator.cs
- ExtentCqlBlock.cs
- InheritanceAttribute.cs
- UntypedNullExpression.cs
- HttpResponseHeader.cs
- RuntimeResourceSet.cs
- TextElementCollectionHelper.cs
- FileLevelControlBuilderAttribute.cs
- IndependentlyAnimatedPropertyMetadata.cs
- SerializationStore.cs
- RelativeSource.cs
- PhysicalFontFamily.cs
- DrawingCollection.cs
- ScrollChangedEventArgs.cs
- SoapInteropTypes.cs
- ValidatingReaderNodeData.cs