Binding.Converter 属性
定义
重要
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获取或设置绑定引擎调用的转换器对象，以在源和目标之间传递数据时修改数据，反之亦然。
public:
property IValueConverter ^ Converter { IValueConverter ^ get(); void set(IValueConverter ^ value); };IValueConverter Converter();
void Converter(IValueConverter value);public IValueConverter Converter { get; set; }var iValueConverter = binding.converter;
binding.converter = iValueConverter;Public Property Converter As IValueConverter<Binding Converter="converterReference"/>
属性值
修改数据的 IValueConverter 对象。
示例
若要在绑定中使用转换器，请先创建转换器类的实例。 以下示例将此显示为 XAML 文件中的资源。
<UserControl.Resources>
<local:DateToStringConverter x:Key="Converter1"/>
</UserControl.Resources>
<TextBlock Grid.Column="0" Margin="5,0"
Text="{Binding Month, Converter={StaticResource Converter1}}"/>
// Custom class implements the IValueConverter interface.
public class DateToStringConverter : IValueConverter
{
#region IValueConverter Members
// Define the Convert method to change a DateTime object to
// a month string.
public object Convert(object value, Type targetType,
object parameter, string language)
{
// The value parameter is the data from the source object.
DateTime thisdate = (DateTime)value;
int monthnum = thisdate.Month;
string month;
switch (monthnum)
{
case 1:
month = "January";
break;
case 2:
month = "February";
break;
default:
month = "Month not found";
break;
}
// Return the month value to pass to the target.
return month;
}
// ConvertBack is not implemented for a OneWay binding.
public object ConvertBack(object value, Type targetType,
object parameter, string language)
{
throw new NotImplementedException();
}
#endregion
}
' Custom class implements the IValueConverter interface.
Public Class DateToStringConverter
Implements IValueConverter
' Define the Convert method to change a DateTime object to
' a month string.
Public Function Convert(ByVal value As Object, _
ByVal targetType As Type, ByVal parameter As Object, _
ByVal language As System.String) As Object _
Implements IValueConverter.Convert
' value is the data from the source object.
Dim thisdate As DateTime = CType(value, DateTime)
Dim monthnum As Integer = thisdate.Month
Dim month As String
Select Case (monthnum)
Case 1
month = "January"
Case 2
month = "February"
Case Else
month = "Month not found"
End Select
' Return the value to pass to the target.
Return month
End Function
' ConvertBack is not implemented for a OneWay binding.
Public Function ConvertBack(ByVal value As Object, _
ByVal targetType As Type, ByVal parameter As Object, _
ByVal language As System.String) As Object _
Implements IValueConverter.ConvertBack
Throw New NotImplementedException
End Function
End Class
注解
通过实现 IValueConverter 接口并实现 Convert 方法创建转换器。 该方法应返回一个对象，该对象的类型与绑定所面向的依赖属性的类型相同，或者至少返回一个可隐式强制转换或转换为目标类型的类型。