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/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / Common / dbenumerator.cs / 1305376 / dbenumerator.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.Common { using System; using System.Collections; using System.Data; using System.Data.ProviderBase; using System.Diagnostics; using System.ComponentModel; public class DbEnumerator : IEnumerator { internal IDataReader _reader; internal IDataRecord _current; internal SchemaInfo[] _schemaInfo; // shared schema info among all the data records internal PropertyDescriptorCollection _descriptors; // cached property descriptors private FieldNameLookup _fieldNameLookup; // MDAC 69015 private bool closeReader; // users must get enumerators off of the datareader interfaces public DbEnumerator(IDataReader reader) { if (null == reader) { throw ADP.ArgumentNull("reader"); } _reader = reader; } public DbEnumerator(IDataReader reader, bool closeReader) { // MDAC 68670 if (null == reader) { throw ADP.ArgumentNull("reader"); } _reader = reader; this.closeReader = closeReader; } public object Current { get { return _current; } } /*public IDataRecord Current { get { return _current; } }*/ /* virtual internal IDataRecord NewRecord(SchemaInfo[] si, object[] values, PropertyDescriptorCollection descriptors) { return new DbDataRecord(si, values, descriptors); } virtual internal void GetValues(object[] values) { _reader.GetValues(values); } */ public bool MoveNext() { if (null == _schemaInfo) { BuildSchemaInfo(); } Debug.Assert(null != _schemaInfo && null != _descriptors, "unable to build schema information!"); _current = null; if (_reader.Read()) { // setup our current record object[] values = new object[_schemaInfo.Length]; _reader.GetValues(values); // this.GetValues() _current = new DataRecordInternal(_schemaInfo, values, _descriptors, _fieldNameLookup); // this.NewRecord() return true; } if (closeReader) { _reader.Close(); } return false; } [ EditorBrowsableAttribute(EditorBrowsableState.Never) ] // MDAC 69508 public void Reset() { throw ADP.NotSupported(); } private void BuildSchemaInfo() { int count = _reader.FieldCount; string[] fieldnames = new string[count]; for (int i = 0; i < count; ++i) { fieldnames[i] = _reader.GetName(i); } ADP.BuildSchemaTableInfoTableNames(fieldnames); // MDAC 71401 SchemaInfo[] si = new SchemaInfo[count]; PropertyDescriptor[] props = new PropertyDescriptor[_reader.FieldCount]; for (int i = 0; i < si.Length; i++) { SchemaInfo s = new SchemaInfo(); s.name = _reader.GetName(i); s.type = _reader.GetFieldType(i); s.typeName = _reader.GetDataTypeName(i); props[i] = new DbColumnDescriptor(i, fieldnames[i], s.type); si[i] = s; } _schemaInfo = si; _fieldNameLookup = new FieldNameLookup(_reader, -1); // MDAC 71470 _descriptors = new PropertyDescriptorCollection(props); } sealed private class DbColumnDescriptor : PropertyDescriptor { int _ordinal; Type _type; internal DbColumnDescriptor(int ordinal, string name, Type type) : base(name, null) { _ordinal = ordinal; _type = type; } public override Type ComponentType { get { return typeof(IDataRecord); } } public override bool IsReadOnly { get { return true; } } public override Type PropertyType { get { return _type; } } public override bool CanResetValue(object component) { return false; } public override object GetValue(object component) { return ((IDataRecord)component)[_ordinal]; } public override void ResetValue(object component) { throw ADP.NotSupported(); } public override void SetValue(object component, object value) { throw ADP.NotSupported(); } public override bool ShouldSerializeValue(object component) { return false; } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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