Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / DataTableReaderListener.cs / 1305376 / DataTableReaderListener.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data { using System; using System.Data.Common; using System.Collections; using System.ComponentModel; internal sealed class DataTableReaderListener { private DataTable currentDataTable = null; private bool isSubscribed = false; private WeakReference readerWeak; internal DataTableReaderListener(DataTableReader reader) { if (reader == null) throw ExceptionBuilder.ArgumentNull("DataTableReader"); if (currentDataTable != null) { UnSubscribeEvents(); } this.readerWeak = new WeakReference(reader); currentDataTable = reader.CurrentDataTable; if (currentDataTable != null) SubscribeEvents(); } internal void CleanUp() { UnSubscribeEvents(); } internal void UpdataTable(DataTable datatable) { if (datatable == null) throw ExceptionBuilder.ArgumentNull("DataTable"); UnSubscribeEvents(); currentDataTable = datatable; SubscribeEvents(); } private void SubscribeEvents() { if (currentDataTable == null) return; if (isSubscribed) return; currentDataTable.Columns.ColumnPropertyChanged += new CollectionChangeEventHandler(SchemaChanged); currentDataTable.Columns.CollectionChanged += new CollectionChangeEventHandler(SchemaChanged); currentDataTable.RowChanged += new DataRowChangeEventHandler(DataChanged ); currentDataTable.RowDeleted += new DataRowChangeEventHandler(DataChanged); currentDataTable.TableCleared += new DataTableClearEventHandler(DataTableCleared); isSubscribed = true; } private void UnSubscribeEvents() { if (currentDataTable == null) return; if (!isSubscribed) return; currentDataTable.Columns.ColumnPropertyChanged -= new CollectionChangeEventHandler(SchemaChanged); currentDataTable.Columns.CollectionChanged -= new CollectionChangeEventHandler(SchemaChanged); currentDataTable.RowChanged -= new DataRowChangeEventHandler(DataChanged ); currentDataTable.RowDeleted -= new DataRowChangeEventHandler(DataChanged); currentDataTable.TableCleared -= new DataTableClearEventHandler(DataTableCleared); isSubscribed = false; } private void DataTableCleared(object sender, DataTableClearEventArgs e) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.DataTableCleared(); } else { UnSubscribeEvents(); } } private void SchemaChanged(object sender, CollectionChangeEventArgs e) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.SchemaChanged(); } else { UnSubscribeEvents(); } } private void DataChanged( object sender, DataRowChangeEventArgs args ) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.DataChanged(args); } else { UnSubscribeEvents(); } } } } // 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.Data.Common; using System.Collections; using System.ComponentModel; internal sealed class DataTableReaderListener { private DataTable currentDataTable = null; private bool isSubscribed = false; private WeakReference readerWeak; internal DataTableReaderListener(DataTableReader reader) { if (reader == null) throw ExceptionBuilder.ArgumentNull("DataTableReader"); if (currentDataTable != null) { UnSubscribeEvents(); } this.readerWeak = new WeakReference(reader); currentDataTable = reader.CurrentDataTable; if (currentDataTable != null) SubscribeEvents(); } internal void CleanUp() { UnSubscribeEvents(); } internal void UpdataTable(DataTable datatable) { if (datatable == null) throw ExceptionBuilder.ArgumentNull("DataTable"); UnSubscribeEvents(); currentDataTable = datatable; SubscribeEvents(); } private void SubscribeEvents() { if (currentDataTable == null) return; if (isSubscribed) return; currentDataTable.Columns.ColumnPropertyChanged += new CollectionChangeEventHandler(SchemaChanged); currentDataTable.Columns.CollectionChanged += new CollectionChangeEventHandler(SchemaChanged); currentDataTable.RowChanged += new DataRowChangeEventHandler(DataChanged ); currentDataTable.RowDeleted += new DataRowChangeEventHandler(DataChanged); currentDataTable.TableCleared += new DataTableClearEventHandler(DataTableCleared); isSubscribed = true; } private void UnSubscribeEvents() { if (currentDataTable == null) return; if (!isSubscribed) return; currentDataTable.Columns.ColumnPropertyChanged -= new CollectionChangeEventHandler(SchemaChanged); currentDataTable.Columns.CollectionChanged -= new CollectionChangeEventHandler(SchemaChanged); currentDataTable.RowChanged -= new DataRowChangeEventHandler(DataChanged ); currentDataTable.RowDeleted -= new DataRowChangeEventHandler(DataChanged); currentDataTable.TableCleared -= new DataTableClearEventHandler(DataTableCleared); isSubscribed = false; } private void DataTableCleared(object sender, DataTableClearEventArgs e) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.DataTableCleared(); } else { UnSubscribeEvents(); } } private void SchemaChanged(object sender, CollectionChangeEventArgs e) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.SchemaChanged(); } else { UnSubscribeEvents(); } } private void DataChanged( object sender, DataRowChangeEventArgs args ) { DataTableReader reader = (DataTableReader) readerWeak.Target; if (reader != null) { reader.DataChanged(args); } else { UnSubscribeEvents(); } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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