mvvm 模板中事件没有执行的解决方案

今天在wpf设计的过程中，用到了listview，数据绑定在模板中进行，其中有个按钮的click事件，一直不执行，很奇怪，找了很久才找到解决办法，原因还是暂时不清除：

<ListView x:Name="LvwClass" ItemsSource="{Binding ClassCollection}" Grid.Column="1">
<ListView.View>
<GridView>
<GridViewColumn Width="60">
<GridViewColumn.Header>
<CheckBox>
<i:Interaction.Triggers>
<i:EventTrigger EventName="Checked">
<command:EventToCommand Command="{Binding ClassCheckChangedCommand}" CommandParameter="True"></command:EventToCommand>
</i:EventTrigger>
<i:EventTrigger EventName="Unchecked">
<command:EventToCommand Command="{Binding ClassCheckChangedCommand}" CommandParameter="False"></command:EventToCommand>
</i:EventTrigger>
</i:Interaction.Triggers>
</CheckBox>
</GridViewColumn.Header>
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox Margin="3,0,0,0" IsChecked="True"></CheckBox>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Width="60" Header="序号">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Converter={StaticResource ListViewIndex},RelativeSource={RelativeSource AncestorType={x:Type ListViewItem}, AncestorLevel=1}}" TextWrapping="Wrap"></TextBlock>

</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Width="60" Header="班级">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding ClassName}" TextWrapping="Wrap"></TextBlock>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Width="60" Header="操作">
<GridViewColumn.CellTemplate>
<DataTemplate>
<Button Content="清除" DataContext="{Binding Id}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<command:EventToCommand Command="{Binding DataContext.ClassItemClearCommand,
RelativeSource={RelativeSource AncestorType=Window,AncestorLevel=1}}"
CommandParameter="{Binding RelativeSource={RelativeSource AncestorType=ListViewItem,AncestorLevel=1},Path=DataContext}"
></command:EventToCommand>

</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>

</GridView>
</ListView.View>
</ListView>