Export (0) Print
Expand All
Expand Minimize

ControlEventHandler Delegate

Represents the method that will handle the ControlAdded and ControlRemoved events of the Control class.

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

public delegate void ControlEventHandler(
	Object sender,
	ControlEventArgs e
)

Parameters

sender
Type: System.Object

The source of the event.

e
Type: System.Windows.Forms.ControlEventArgs

A ControlEventArgs that contains the event data.

When you create a ControlEventArgs delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Handling and Raising Events.

The following code example creates a Binding, adds a ConvertEventHandler delegate to both the Parse and Format events, and adds the Binding to the BindingsCollection of a TextBox control through the DataBindings property. The DecimalToCurrencyString event delegate, added to the Format event, formats the bound value (a Decimal type) as currency using the ToString method. The CurrencyStringToDecimal event delegate, added to the Parse event, converts the value displayed by the control back to the Decimal type.

private void BindControl()
{
   // Create the binding first. The OrderAmount is typed as Decimal.
   Binding b = new Binding
      ("Text", ds, "customers.custToOrders.OrderAmount");
   // Add the delegates to the events.
   b.Format += new ConvertEventHandler(DecimalToCurrencyString);
   b.Parse += new ConvertEventHandler(CurrencyStringToDecimal);
   text1.DataBindings.Add(b);
}

private void DecimalToCurrencyString(object sender, ConvertEventArgs cevent)
{
   // Check for the appropriate DesiredType. 
   if(cevent.DesiredType != typeof(string)) return;

   // Use the ToString method to format the value as currency ("c").
   cevent.Value = ((decimal) cevent.Value).ToString("c");
}

private void CurrencyStringToDecimal(object sender, ConvertEventArgs cevent)
{
   // Check for the appropriate DesiredType.  
   if(cevent.DesiredType != typeof(decimal)) return;

   // Convert the string back to decimal using the static Parse method.
   cevent.Value = Decimal.Parse(cevent.Value.ToString(),
   NumberStyles.Currency, null);
}

.NET Framework

Supported in: 4.5.3, 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.

Show:
© 2014 Microsoft