DataColumnCollection.CollectionChanged Event

Reference

Definition

Namespace:: System.Data

Assemblies:: netstandard.dll, System.Data.Common.dll

Assembly:: System.Data.Common.dll

Assembly:: System.Data.dll

Assembly:: netstandard.dll

Source:: DataColumnCollection.cs

Source:: DataColumnCollection.cs

Source:: DataColumnCollection.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Occurs when the columns collection changes, either by adding or removing a column.

public:
 event System::ComponentModel::CollectionChangeEventHandler ^ CollectionChanged;

public event System.ComponentModel.CollectionChangeEventHandler? CollectionChanged;

public event System.ComponentModel.CollectionChangeEventHandler CollectionChanged;

member this.CollectionChanged : System.ComponentModel.CollectionChangeEventHandler

Public Custom Event CollectionChanged As CollectionChangeEventHandler

Event Type

CollectionChangeEventHandler

Examples

The following example adds an event handler for the CollectionChanged event.

private void AddEventHandler(DataTable table)
{
    DataColumnCollection columns = table.Columns;
    columns.CollectionChanged += new
        System.ComponentModel.CollectionChangeEventHandler(
        ColumnsCollection_Changed);
}

private void ColumnsCollection_Changed(object sender,
    System.ComponentModel.CollectionChangeEventArgs e)
{
    DataColumnCollection columns =
        (DataColumnCollection) sender;
    Console.WriteLine("ColumnsCollectionChanged: "
        + columns.Count);
}

 Private Sub AddEventHandler(table As DataTable)
     Dim columns As DataColumnCollection = table.Columns
     AddHandler columns.CollectionChanged, _
        AddressOf ColumnsCollection_Changed
 End Sub    
    
 Private Sub ColumnsCollection_Changed _
    (sender As Object, e As System.ComponentModel. _
    CollectionChangeEventArgs)

     Dim columns As DataColumnCollection = _
        CType(sender, DataColumnCollection)
     Console.WriteLine("ColumnsCollectionChanged: " _
        & columns.Count.ToString())
End Sub

Remarks

Use the Contains and CanRemove methods to determine whether a column exists and can be removed.

Applies to

Proizvod	Verzije
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

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