ColumnChanged |
DataColumnChangeEventHandler ColumnChanged; |
The ColumnChanged event is raised after the value for a column in the DataRow has been changed.
The following code demonstrates how to handle the ColumnChanged event:
DataTable dt = new DataTable(); dt.ColumnChanged += new DataColumnChangeEventHandler(dt_ColumnChanged); private void dt_ColumnChanged(object sender, DataColumnChangeEventArgs e) { MessageBox.Show("ColumnChanged: Name = " + e.Column.ColumnName + "; " + "ProposedValue = " + e.ProposedValue.ToString() + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataColumnChangeEventArgs containing properties that provide specific information about the event as described in Table 23-13.
Property | Description |
---|---|
Column | Returns a reference to the DataColumn that changes. |
ProposedValue | Gets or sets a reference to an object representing the proposed value for the column. |
Row | Returns a reference to the DataRow of the column that changes. |
ColumnChanging |
DataColumnChangeEventHandler ColumnChanging; |
The ColumnChanging event is raised when the value for column in the DataRow is being changed.
The following code demonstrates how to handle the ColumnChanging event:
DataTable dt = new DataTable(); dt.ColumnChanging += new DataColumnChangeEventHandler(dt_ColumnChanging); private void dt_ColumnChanging(object sender, DataColumnChangeEventArgs e) { MessageBox.Show("ColumnChanging: Name = " + e.Column.ColumnName + "; " + "ProposedValue = " + e.ProposedValue.ToString() + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataColumnChangeEventArgs , which contains properties that provide specific information about the event as described in Table 23-13.
RowChanged |
DataRowChangeEventHandler RowChanged; |
The RowChanged event is raised after a DataRow is successfully changed.
The following code demonstrates how to handle the RowChanged event:
DataTable dt = new DataTable(); dt.RowChanged += new DataRowChangeEventHandler(dt_RowChanged); private void dt_RowChanged(object sender, DataRowChangeEventArgs e) { MessageBox.Show("RowChanged: Action = " + e.Action + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataRowChangeEventArgs , which contains properties that provide specific information about the event as described in Table 23-14. DataRowAction enumeration is covered in Table 23-15.
Property | Description |
---|---|
Action | Returns the action that has occurred on the DataRow . This value is from the DataRowAction enumeration as described in the next table. |
Row | Returns a reference to the DataRow that is changing or being deleted. |
Value | Description |
---|---|
Add | The row has been added to the table. |
Change | The row has been modified. |
Commit | The changes made to the row have been committed. |
Delete | The row has been deleted from the table. |
Nothing | The row has not been changed. |
Rollback | The changes made to the row have been rolled back. |
RowChanging |
DataRowChangeEventHandler RowChanging; |
The RowChanging event is raised when a DataRow is about to be changed.
The following code demonstrates how to handle the RowChanging event:
DataTable dt = new DataTable(); dt.RowChanging += new DataRowChangeEventHandler(dt_RowChanging); private void dt_RowChanging(object sender, DataRowChangeEventArgs e) { MessageBox.Show("RowChanging: Action = " + e.Action + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataRowChangeEventArgs , which contains properties that provide specific information about the event as described in Table 23-14.
RowDeleted |
DataRowChangeEventHandler RowDeleted; |
The RowDeleted event is raised after a row is deleted from the table.
The following code demonstrates how to handle the RowDeleted event:
DataTable dt = new DataTable(); dt.RowDeleted += new DataRowChangeEventHandler(dt_RowDeleted); private void dt_RowDeleted(object sender, DataRowChangeEventArgs e) { MessageBox.Show("RowDeleted: Action = " + e.Action + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataRowChangeEventArgs , which contains properties that provide specific information about the event as described in Table 23-14.
RowDeleting |
DataRowChangeEventHandler RowDeleting; |
The RowDeleting event is raised when a row is about to be deleted from the table.
The following code demonstrates how to handle the RowDeleting event:
DataTable dt = new DataTable(); dt.RowDeleting += new DataRowChangeEventHandler(dt_RowDeleting); private void dt_RowDeleting(object sender, DataRowChangeEventArgs e) { MessageBox.Show("RowDeleting: Action = " + e.Action + "; " + "Row Id = " + e.Row["Id"].ToString()); }
The event handler receives an argument of type DataRowChangeEventArgs , which contains properties that provide specific information about the event as described in Table 23-14.