ZoomPercentageConverter.ConvertBack Method (Object, Type, Object, CultureInfo)


Returns a previously converted value of DocumentViewer.Zoom back to a Double that can be assigned to DocumentViewer.Zoom.

Namespace:   System.Windows.Documents
Assembly:  PresentationFramework (in PresentationFramework.dll)

public object ConvertBack(
	object value,
	Type targetType,
	object parameter,
	CultureInfo culture


Type: System.Object

The object that is to be converted back to a Double.

Type: System.Type

The type of value. This must be Double or String. See Remarks.

Type: System.Object

null. See Remarks.

Type: System.Globalization.CultureInfo

The language and culture assumed during the conversion.

Return Value

Type: System.Object

UnsetValue when the converter cannot produce a value; for example, when value is not a valid percentage when targetType is not Double or String.

- or -

A Double representing the zoom percentage of a DocumentViewer.

The data binding engine calls this method when it moves a value from the binding target to the binding source.

UnsetValue may be returned to indicate that the converter produced no value and that the fallback (if available) or default value should be used instead.

Pass null for parameter. This parameter is required by the signature of ConvertBack, and is used by some implementations to provide contextual information to the converter; but it is not used in this class.

.NET Framework
Available since 3.0
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