WPF，数据绑定，为什么没有自动跟新

Question

<StackPanel Name="stackpanel1" DataContext="{x:Static SystemFonts.IconFontFamily}">
    <TextBlock Text="{Binding Path=Source}" />
    <TextBlock Text="{Binding Path=LineSpacing}" />
    <TextBlock Text="{Binding Path=FamilyTypefaces[0].Style}" />
    <TextBlock Text="{Binding Path=FamilyTypefaces[0].Weight}" />
    <Button Content="Button" Click="Button_Click"/>
</StackPanel>private void Button_Click(object sender, RoutedEventArgs e)
{
    stackpanel1.DataContext = SystemFonts.MessageFontFamily;
}点击Button之后，修改了StackPanel的DataContext，为什么TextBlock的数据没有更新呢？

Answer 1

我猜测 IconFontFamily 与 MessageFontFamily 的各个属性值是一样的        <StackPanel Name="stackpanel1" >
            <TextBlock Text="{Binding Path=Source}" />
            <TextBlock Text="{Binding Path=LineSpacing}" />
            <TextBlock Text="{Binding Path=FamilyTypefaces[0].Style}" />
            <TextBlock Text="{Binding Path=FamilyTypefaces[0].Weight}" />
            <Button Content="Button" Click="Button_Click"/>
        </StackPanel>去掉初始时 DataContext 的值 
使用Button进行更新是 可以更新的