WPF：DataContext设置之前的转换器默认值

Question

Now I am working with WPF. My Controls visibility binded like in here:

<Button Content="Click me!" Visibility="{Binding Path=SomePath,  Converter={StaticResource MessageCloseConverter}}"/>

This works after DataContext is setted. But when I run project first time DataContext is null and Visibility is Visible.I want set visibility collapsed first time and after setting DataContext converter should work like now.

Answer 1

使用FallbackValue属性：

<Button Content="Click me!" Visibility="{Binding Path=SomePath,  Converter={StaticResource MessageCloseConverter}, FallbackValue=Collapsed}"/>