DataSet.MergeFailed Gebeurtenis
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Treedt op wanneer een doel en bron DataRow dezelfde primaire-sleutelwaarde hebben en EnforceConstraints is ingesteld op waar.
public:
event System::Data::MergeFailedEventHandler ^ MergeFailed;
public event System.Data.MergeFailedEventHandler? MergeFailed;
public event System.Data.MergeFailedEventHandler MergeFailed;
[System.Data.DataSysDescription("DataSetMergeFailedDescr")]
public event System.Data.MergeFailedEventHandler MergeFailed;
member this.MergeFailed : System.Data.MergeFailedEventHandler
[<System.Data.DataSysDescription("DataSetMergeFailedDescr")>]
member this.MergeFailed : System.Data.MergeFailedEventHandler
Public Custom Event MergeFailed As MergeFailedEventHandler
Gebeurtenistype
- Kenmerken
Voorbeelden
In het volgende voorbeeld ziet u het gebruik van de MergeFailed gebeurtenis.
private static void DemonstrateMergeFailedEvent()
{
// Create a DataSet with one table containing two columns.
DataSet dataSet = new DataSet("dataSet");
DataTable table = new DataTable("Items");
// Add table to the DataSet.
dataSet.Tables.Add(table);
// Add two columns to the DataTable.
table.Columns.Add("id", typeof(int));
table.Columns.Add("item", typeof(int));
// Set the primary key to the first column.
table.PrimaryKey = new DataColumn[] { table.Columns["id"] };
// Add MergeFailed event handler for the table.
dataSet.MergeFailed += new MergeFailedEventHandler(Merge_Failed);
// Create a second DataTable identical to the first,
DataTable t2 = table.Clone();
// Set the primary key of the new table to the second column.
// This will cause the MergeFailed event to be raised when the
// table is merged into the DataSet.
t2.PrimaryKey = new DataColumn[] { t2.Columns["item"] };
// Merge the table into the DataSet.
Console.WriteLine("Merging...");
dataSet.Merge(t2, false, MissingSchemaAction.Add);
}
private static void Merge_Failed(object sender, MergeFailedEventArgs e)
{
Console.WriteLine("Merge_Failed Event: '{0}'", e.Conflict);
}
Private Shared Sub DemonstrateMergeFailedEvent()
' Create a DataSet with one table containing two columns.
Dim dataSet As New DataSet("dataSet")
Dim table As New DataTable("Items")
' Add table to the DataSet.
dataSet.Tables.Add(table)
' Add two columns to the DataTable.
table.Columns.Add("id", Type.GetType("System.Int32"))
table.Columns.Add("item", Type.GetType("System.Int32"))
' Set the primary key to the first column.
table.PrimaryKey = new DataColumn() { table.Columns("id") }
' Add MergeFailed event handler for the table.
AddHandler dataSet.MergeFailed, _
New MergeFailedEventHandler(AddressOf Merge_Failed)
' Create a second DataTable identical to the first,
Dim t2 As DataTable = table.Clone()
' Set the primary key of the new table to the second column.
' This will cause the MergeFailed event to be raised when the
' table is merged into the DataSet.
t2.PrimaryKey = New DataColumn() { t2.Columns("item") }
' Merge table into the DataSet.
Console.WriteLine("Merging...")
dataSet.Merge(t2, false, MissingSchemaAction.Add)
End Sub
Private Shared Sub Merge_Failed(sender As object, _
e As MergeFailedEventArgs)
Console.WriteLine("Merge_Failed Event: '{0}'", e.Conflict)
End Sub
Opmerkingen
Zie Gebeurtenissen verwerken en genereren voor meer informatie over het afhandelen van gebeurtenissen.