Clear メソッドは、すべての行をコレクションから削除します。これはSetCount(Int32) を呼び出してカウントを 0 に設定するのと同じです。注: このメソッドを呼び出したときにRowDeletingイベントとRowDeletedイベントは発生しません。
Imports Infragistics.Shared Imports Infragistics.Win Imports Infragistics.Win.UltraWinDataSource Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles button1.Click Dim ds As UltraDataSource = New UltraDataSource() Dim col1 As UltraDataColumn = ds.Band.Columns.Add("ID", GetType(Integer)) Dim col2 As UltraDataColumn = ds.Band.Columns.Add("Col2", GetType(String)) Dim row As UltraDataRow Dim i As Integer For i = 0 To 5 - 1 ' Look below where we call the Insert method for explanation on ' what raiseAddEvents parameter does. row = ds.Rows.Add(True, New Object() {i, "Val " & i}) Next ' Insert a row at index 0. A new row will be created and added to the ' collection at the specified index. RaiseAddEvents parameter of Add and ' Insert methods indicates whether the UltraDataSource should raise it's ' own RowAdding and RowAdded events. It does not indicate whether ' IBindingList.ListChanged event is raised or not. ' IBindingList.ListChanged event will always be raised regardless of the ' value of this parameter. This is useful when you have some logic in ' those event handlers for initializing new rows and you want that logic ' to be executed for the new row that you are inserting. If you use the ' overloads of Add or Insert that do not take raiseAddEvents parameter ' then add events won't be raised. row = ds.Rows.Insert(0, False, New Object() {-1, "Val -1"}) ' Remove the inserted row. RaiseDeleteEvents parameter is analogous to ' the raiseAddEvents parameter of the Add and Insert methods. Look above ' where we call Insert for an explanation. row.ParentCollection.Remove(row, False) ' To check if a row is in a collection, use the Contains method. ' Following should print out false since the row has been deleted. Debug.WriteLine("Is deleted row in collection ? " & row.ParentCollection.Contains(row)) ' A deleted row will have the index of -1. Following should print out -1 ' since the row is not in the collection anymore. Row's Index property ' and IndexOf methods give the same results. Debug.WriteLine("Deleted row's index is " & row.Index) Debug.WriteLine("Deleted row's index is " & row.ParentCollection.IndexOf(row)) ' You can also use the RemoveAt method to remove a row by specifying the ' index of the row instead of the row itself. ds.Rows.RemoveAt(0, False) ' Print out the row count. This should print 4 as the row count since we ' added 5 using Add method in the for loop above and then added one ' using the Insert method above and then removed two using Remove and ' RemoveAt methods each. Debug.WriteLine("Row count = " & ds.Rows.Count) ' You can remove all rows from a row collection using Clear method. This ' is more efficient than deleting individual rows using Remove or ' RemoveAt methods. ds.Rows.Clear() ' You can use the SetCount method to add multiple rows at once. This can ' be more efficient than adding individual rows using Add method when ' adding a lot of rows. ds.Rows.SetCount(5) ' Add another 5 rows by setting the count to 10. Previously we added 5 ' rows when we called SetCount( 5 ) above. Calling SetCount with 10 will ' add another 5 rows so that the new count becomes 10. ds.Rows.SetCount(10) ' Following line should print out 10. Debug.WriteLine("Row count = " & ds.Rows.Count) ds.Rows.SetCount(100000) ' Following line should print out 100000. Debug.WriteLine("Row count = " & ds.Rows.Count) End Sub
using Infragistics.Shared; using Infragistics.Win; using Infragistics.Win.UltraWinDataSource; using System.Diagnostics; private void button1_Click(object sender, System.EventArgs e) { UltraDataSource ds = new UltraDataSource( ); UltraDataColumn col1 = ds.Band.Columns.Add( "ID", typeof( int ) ); UltraDataColumn col2 = ds.Band.Columns.Add( "Col2", typeof( string ) ); UltraDataRow row; for ( int i = 0; i < 5; i++ ) { // Look below where we call the Insert method for explanation on // what raiseAddEvents parameter does. row = ds.Rows.Add( true, new object[] { i, "Val " + i } ); } // Insert a row at index 0. A new row will be created and added to the // collection at the specified index. RaiseAddEvents parameter of Add and // Insert methods indicates whether the UltraDataSource should raise it's // own RowAdding and RowAdded events. It does not indicate whether // IBindingList.ListChanged event is raised or not. // IBindingList.ListChanged event will always be raised regardless of the // value of this parameter. This is useful when you have some logic in // those event handlers for initializing new rows and you want that logic // to be executed for the new row that you are inserting. If you use the // overloads of Add or Insert that do not take raiseAddEvents parameter // then add events won't be raised. row = ds.Rows.Insert( 0, false, new object[] { -1, "Val -1" } ); // Remove the inserted row. RaiseDeleteEvents parameter is analogous to // the raiseAddEvents parameter of the Add and Insert methods. Look above // where we call Insert for an explanation. row.ParentCollection.Remove( row, false ); // To check if a row is in a collection, use the Contains method. // Following should print out false since the row has been deleted. Debug.WriteLine( "Is deleted row in collection ? " + row.ParentCollection.Contains( row ) ); // A deleted row will have the index of -1. Following should print out -1 // since the row is not in the collection anymore. Row's Index property // and IndexOf methods give the same results. Debug.WriteLine( "Deleted row's index is " + row.Index ); Debug.WriteLine( "Deleted row's index is " + row.ParentCollection.IndexOf( row ) ); // You can also use the RemoveAt method to remove a row by specifying the // index of the row instead of the row itself. ds.Rows.RemoveAt( 0, false ); // Print out the row count. This should print 4 as the row count since we // added 5 using Add method in the for loop above and then added one // using the Insert method above and then removed two using Remove and // RemoveAt methods each. Debug.WriteLine( "Row count = " + ds.Rows.Count ); // You can remove all rows from a row collection using Clear method. This // is more efficient than deleting individual rows using Remove or // RemoveAt methods. ds.Rows.Clear( ); // You can use the SetCount method to add multiple rows at once. This can // be more efficient than adding individual rows using Add method when // adding a lot of rows. ds.Rows.SetCount( 5 ); // Add another 5 rows by setting the count to 10. Previously we added 5 // rows when we called SetCount( 5 ) above. Calling SetCount with 10 will // add another 5 rows so that the new count becomes 10. ds.Rows.SetCount( 10 ); // Following line should print out 10. Debug.WriteLine( "Row count = " + ds.Rows.Count ); ds.Rows.SetCount( 100000 ); // Following line should print out 100000. Debug.WriteLine( "Row count = " + ds.Rows.Count ); }