用WPF在一个XAML中写了以下代码:
        <Style x:Key="buttonMouseOver">
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="true">
                    <Setter Property="Background" Value="#FF0CC030"/>
                </Trigger>
            </Style.Triggers>
        </Style>确在Background处提示标题的错误,请问是什么原因?