当鼠标移动到button上面时，按钮变色  

<StackPanel TextElement.FontSize="15">
            <Label x:Name="lblHello" Content="" Background="Bisque" />
            <Button x:Name="btnHello" Content="clickMe" Height="24" Width="60" Click="btnHello_Click" >
                <Button.Style>
                    <Style TargetType="Button">
                        <Style.Triggers>
                            <Trigger Property="IsMouseOver" Value="True">
                                <Setter Property="Foreground" Value="Blue"></Setter>
                                <Setter Property="Background" Value="#00ff00"></Setter>
                            </Trigger>
                        </Style.Triggers>
                    </Style>
                </Button.Style>


            </Button>


        </StackPanel>