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ConvertEventHandler Delegate

Represents the method that will handle the Parse and Format events of a Binding.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public delegate void ConvertEventHandler (
	Object sender,
	ConvertEventArgs e
)
/** @delegate */
public delegate void ConvertEventHandler (
	Object sender, 
	ConvertEventArgs e
)
Not applicable.

Parameters

sender

The source of the event.

e

A ConvertEventArgs that contains the event data.

When you create a ConvertEventHandler 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 Events and Delegates.

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 DecimalToCurrency event delegate, added to the Format event, formats the bound value (a Decimal type) as currency using the ToString method. The CurrencyToDecimal event delegate, added to the Parse event, converts the value displayed by the control back to the Decimal type.

private void DecimalToCurrency(object sender, ConvertEventArgs cevent)
{
   // The method converts only to string type. Test this using the 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 CurrencyToDecimal(object sender, ConvertEventArgs cevent)
{
   // ' The method converts only to decimal type. 
   if (cevent.DesiredType != typeof(decimal)) return;

   // Converts the string back to decimal using the static ToDecimal method.
   cevent.Value = Convert.ToDecimal(cevent.Value.ToString());
}

private void BindControl()
{
   // Creates 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(DecimalToCurrency);
   b.Parse += new ConvertEventHandler(CurrencyToDecimal);
   text1.DataBindings.Add(b);
}


private void DecimalToCurrency(Object sender, ConvertEventArgs cevent)
{
    // The method converts only to string type. 
    // Test this using the DesiredType.
    if (!(cevent.get_DesiredType().Equals(String.class.ToType()))) {
        return ;
    }
    // Use the ToString method to format the value as currency ("c").
    cevent.set_Value(((System.Decimal)cevent.get_Value()).ToString("c"));
} //DecimalToCurrency

private void CurrencyToDecimal(Object sender, ConvertEventArgs cevent)
{
    //  The method converts only to decimal type. 
    if (!(cevent.get_DesiredType().Equals(System.Decimal.class.ToType()))) {
        return ;
    }
    // Converts the string back to decimal 
    // using the static ToDecimal method.
    cevent.set_Value(Convert.ToDecimal(cevent.get_Value().ToString()));
} //CurrencyToDecimal

private void BindControl()
{
    // Creates 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.add_Format(new ConvertEventHandler(DecimalToCurrency));
    b.add_Parse(new ConvertEventHandler(CurrencyToDecimal));
    text1.get_DataBindings().Add(b);
} //BindControl

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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