数据触发器更改另一个元素的属性

Question

我有组合框和文本框。当我改变组合框的选择项时，我想通过组合框对象的一些条件改变文本框的属性，我不知道怎么做。

下面是我的代码:

xaml

<ComboBox x:Name="someItems" Style="{StaticResource comboBoxItems}" />
<TextBox x:Name="myTextBox" />

app.xaml

<Style x:Key="comboBoxItems" TargetType="ComboBox">
<Setter Property="ItemContainerStyle">
<Setter.Value>
<Style TargetType="ComboBoxItem">
<Style.Triggers>                          
<DataTrigger >
//here is missing the binding code
<Setter Property="somepropertyoftextboxobject" Value="somevalue"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Setter.Value>
</Setter>
</Style>

Answer 1

<ComboBox x:Name="cBox" ItemsSource="{Binding ....}"/>
<TextBox>
<TextBox.Style>
<Style TargetType="TextBox">
<Style.Triggers>
<DataTrigger Binding="{Binding SelectedItem.SomeProperty, ElementName=cBox}"
Value="SomeValue">
<!--Setters for TextBox-->
<Setter Property="FontSize" Value="10"/>
<Setter Property="Background" Value="Green"/>
</DataTrigger>
<DataTrigger Binding="{Binding SelectedItem.SomeProperty, ElementName=cBox}"
Value="OtherValue">
<!--Setters for TextBox-->
<Setter Property="FontSize" Value="15"/>
<Setter Property="Background" Value="Blue"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>