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ListView.OnAfterLabelEdit Method

Raises the AfterLabelEdit event.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

protected virtual void OnAfterLabelEdit(
	LabelEditEventArgs e
)

Parameters

e
Type: System.Windows.Forms.LabelEditEventArgs

A LabelEditEventArgs that contains the event data.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnAfterLabelEdit method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors

When overriding OnAfterLabelEdit in a derived class, be sure to call the base class's OnAfterLabelEdit method so that registered delegates receive the event.

The following code example demonstrates how to use the AfterLabelEdit event to restrict a newly edited label to characters in the alphabet. The example uses the ASCIIEncoding class to obtain the ASCII character code of each character of the new label. If the character falls between the ASCII codes that represent numbers, the new label cannot be applied to the item. This example requires that you have created a ListView control on a form and added items to it. The example also requires that you have connected the AfterLabelEdit event to the event handler defined in the example code. In order to use the ASCIIEncoding class, your file must include the System.Text namespace.

private void MyListView_AfterLabelEdit(object sender, System.Windows.Forms.LabelEditEventArgs e)
{

   // Determine if label is changed by checking for null. 
   if (e.Label == null)
      return;

   // ASCIIEncoding is used to determine if a number character has been entered.
   ASCIIEncoding AE = new ASCIIEncoding();
   // Convert the new label to a character array. 
   char[] temp = e.Label.ToCharArray();

   // Check each character in the new label to determine if it is a number. 
   for(int x=0; x < temp.Length; x++)
   {
      // Encode the character from the character array to its ASCII code. 
      byte[] bc = AE.GetBytes(temp[x].ToString());

      // Determine if the ASCII code is within the valid range of numerical values. 
      if(bc[0] > 47 && bc[0] < 58)
      {
         // Cancel the event and return the lable to its original state.
         e.CancelEdit = true;
         // Display a MessageBox alerting the user that numbers are not allowed.
         MessageBox.Show ("The text for the item cannot contain numerical values.");
         // Break out of the loop and exit. 
         return;
      }
   }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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