<ListBox IsSynchronizedWithCurrentItem="True" 
         SelectedValue="{Binding SelectedSnapshotValue}" .../>

然后,当我在视图模型中调用ResetSelection()时,SelectedSnapshotValue被设置为null,

void ResetSelection()
{
    SelectedSnapshotValue = null;
}

使用绑定属性更新数据模板中的绑定：

private Snapshotviewmodel selectedSnapshotValue;
    public Snapshotviewmodel SelectedSnapshotValue
    {
        get { return selectedSnapshotValue; }
        set
        {
            if (selectedSnapshotValue != value)
            {
                selectedSnapshotValue = value;
                RaisePropertyChanged("SelectedSnapshotValue");
            }
        }
    }

这是我能够让我的列表框重置选择的唯一方法.