尝试这个 - 根据您的代码更改 ItemsSource 和 SelectedValue。我刚刚展示了如何实现这一目标..
<ComboBox Height="23" Name="comboBox1" Width="120" ItemsSource="{Binding OCString,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,RelativeSource={RelativeSource AncestorType=Window}}" SelectedValue="{Binding Selected,Mode=TwoWay,RelativeSource={RelativeSource AncestorType=Window},UpdateSourceTrigger=PropertyChanged}">
<ComboBox.Style>
<Style TargetType="{x:Type ComboBox}">
<Style.Triggers>
<Trigger Property="SelectedIndex" Value="-1">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<ComboBox Text="Select an Item" IsReadOnly="True" IsEditable="True" ItemsSource="{Binding OCString,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,RelativeSource={RelativeSource AncestorType=Window}}" SelectedValue="{Binding Selected,Mode=TwoWay,RelativeSource={RelativeSource AncestorType=Window},UpdateSourceTrigger=PropertyChanged}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
</ComboBox.Style>
</ComboBox>
或者简单地->
<ComboBox Text="Select an Item" IsReadOnly="True" IsEditable="True" ItemsSource="{Binding OCString,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,RelativeSource={RelativeSource AncestorType=Window}}" SelectedValue="{Binding Selected,Mode=TwoWay,RelativeSource={RelativeSource AncestorType=Window},UpdateSourceTrigger=PropertyChanged}"/>