Code:
/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / ProviderBase / DataReaderContainer.cs / 1 / DataReaderContainer.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //----------------------------------------------------------------------------- namespace System.Data.ProviderBase { using System; using System.Data; using System.Data.Common; using System.Diagnostics; internal abstract class DataReaderContainer { protected readonly IDataReader _dataReader; protected int _fieldCount; static internal DataReaderContainer Create(IDataReader dataReader, bool returnProviderSpecificTypes) { if (returnProviderSpecificTypes) { DbDataReader providerSpecificDataReader = (dataReader as DbDataReader); if (null != providerSpecificDataReader) { return new ProviderSpecificDataReader(dataReader, providerSpecificDataReader); } } return new CommonLanguageSubsetDataReader(dataReader); } protected DataReaderContainer(IDataReader dataReader) { Debug.Assert(null != dataReader, "null dataReader"); _dataReader = dataReader; } internal int FieldCount { get { return _fieldCount; } } internal abstract bool ReturnProviderSpecificTypes { get; } protected abstract int VisibleFieldCount { get; } internal abstract Type GetFieldType(int ordinal); internal abstract object GetValue(int ordinal); internal abstract int GetValues(object[] values); internal string GetName(int ordinal) { string fieldName = _dataReader.GetName(ordinal); Debug.Assert(null != fieldName, "null GetName"); return ((null != fieldName) ? fieldName : ""); } internal DataTable GetSchemaTable() { return _dataReader.GetSchemaTable(); } internal bool NextResult() { _fieldCount = 0; if (_dataReader.NextResult()) { _fieldCount = VisibleFieldCount; return true; } return false; } internal bool Read() { return _dataReader.Read(); } private sealed class ProviderSpecificDataReader : DataReaderContainer { private DbDataReader _providerSpecificDataReader; internal ProviderSpecificDataReader(IDataReader dataReader, DbDataReader dbDataReader) : base(dataReader) { Debug.Assert(null != dataReader, "null dbDataReader"); _providerSpecificDataReader = dbDataReader; _fieldCount = VisibleFieldCount; } internal override bool ReturnProviderSpecificTypes { get { return true; } } protected override int VisibleFieldCount { get { int fieldCount = _providerSpecificDataReader.VisibleFieldCount; Debug.Assert(0 <= fieldCount, "negative FieldCount"); return ((0 <= fieldCount) ? fieldCount : 0); } } internal override Type GetFieldType(int ordinal) { Type fieldType = _providerSpecificDataReader.GetProviderSpecificFieldType(ordinal); Debug.Assert(null != fieldType, "null FieldType"); return fieldType; } internal override object GetValue(int ordinal) { return _providerSpecificDataReader.GetProviderSpecificValue(ordinal); } internal override int GetValues(object[] values) { return _providerSpecificDataReader.GetProviderSpecificValues(values); } } private sealed class CommonLanguageSubsetDataReader : DataReaderContainer { internal CommonLanguageSubsetDataReader(IDataReader dataReader ) : base(dataReader) { _fieldCount = VisibleFieldCount; } internal override bool ReturnProviderSpecificTypes { get { return false; } } protected override int VisibleFieldCount { get { int fieldCount = _dataReader.FieldCount; Debug.Assert(0 <= fieldCount, "negative FieldCount"); return ((0 <= fieldCount) ? fieldCount : 0); } } internal override Type GetFieldType(int ordinal) { return _dataReader.GetFieldType(ordinal); } internal override object GetValue(int ordinal) { return _dataReader.GetValue(ordinal); } internal override int GetValues(object[] values) { return _dataReader.GetValues(values); } } } } // 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
- HttpHandlerAction.cs
- UpdateDelegates.Generated.cs
- RegexReplacement.cs
- D3DImage.cs
- SamlAdvice.cs
- DataObjectMethodAttribute.cs
- ExpandCollapseProviderWrapper.cs
- HttpFileCollectionWrapper.cs
- DataGridPagerStyle.cs
- ForeignKeyFactory.cs
- Metadata.cs
- DesignerTransactionCloseEvent.cs
- AnnotationHelper.cs
- MarginCollapsingState.cs
- SimpleMailWebEventProvider.cs
- StatusBarItemAutomationPeer.cs
- JavaScriptString.cs
- DataError.cs
- DEREncoding.cs
- ButtonBaseAutomationPeer.cs
- securestring.cs
- sqlcontext.cs
- WebPartCatalogAddVerb.cs
- AssemblyAttributes.cs
- SurrogateEncoder.cs
- ContextMenu.cs
- NativeRecognizer.cs
- XmlEntity.cs
- ReverseQueryOperator.cs
- ListViewHitTestInfo.cs
- ProcessThread.cs
- FileDataSourceCache.cs
- AssemblyBuilder.cs
- DesignerLoader.cs
- ScriptManager.cs
- HttpValueCollection.cs
- PointValueSerializer.cs
- ListDataBindEventArgs.cs
- safemediahandle.cs
- DataGridAddNewRow.cs
- SiteIdentityPermission.cs
- FixedSOMSemanticBox.cs
- StyleCollectionEditor.cs
- OdbcFactory.cs
- TabControl.cs
- SplineKeyFrames.cs
- ItemChangedEventArgs.cs
- PackUriHelper.cs
- TimeSpanFormat.cs
- FileSystemWatcher.cs
- DeclaredTypeValidator.cs
- basenumberconverter.cs
- IfJoinedCondition.cs
- LinqDataSourceUpdateEventArgs.cs
- XmlException.cs
- MediaElementAutomationPeer.cs
- DataServiceStreamResponse.cs
- WSSecureConversation.cs
- odbcmetadatacollectionnames.cs
- SmtpException.cs
- Delegate.cs
- CorrelationTokenTypeConvertor.cs
- RIPEMD160.cs
- ToolStripControlHost.cs
- DataGridViewColumnEventArgs.cs
- TrackingMemoryStream.cs
- PasswordRecovery.cs
- QueueProcessor.cs
- MostlySingletonList.cs
- WriteFileContext.cs
- Compress.cs
- ActivityDesignerResources.cs
- SqlCommandBuilder.cs
- ContentType.cs
- ConstraintStruct.cs
- BindingNavigator.cs
- DrawingGroup.cs
- Queue.cs
- Atom10FormatterFactory.cs
- ConfigurationFileMap.cs
- MembershipPasswordException.cs
- ColorMap.cs
- GridViewRowPresenterBase.cs
- ViewPort3D.cs
- ModuleBuilderData.cs
- XmlUTF8TextReader.cs
- VisualStyleInformation.cs
- InputBuffer.cs
- SecurityPolicySection.cs
- MultiSelectRootGridEntry.cs
- SqlNodeAnnotations.cs
- ViewStateModeByIdAttribute.cs
- ServiceContractDetailViewControl.cs
- ListViewDataItem.cs
- TextRangeEditLists.cs
- PackagePart.cs
- HelpInfo.cs
- QilIterator.cs
- LoginDesigner.cs
- StrongNameHelpers.cs