<StackPanel>

        <Button Content="按钮1" ToolTip="这是个按钮1" HorizontalAlignment="Center" Margin="0,10,0,0"/>

        <Button Content="按钮2"  HorizontalAlignment="Center" Margin="0,10,0,0">

            <Button.ToolTip>

                <ToolTip Background="Yellow">

                    <StackPanel>

                        <TextBlock Text="这是个按钮2"/>

                        <Image Source="C:/Users/Jv/Desktop/lena512.tiff" Width="50" Height="50"/>

                    </StackPanel>

                </ToolTip>

            </Button.ToolTip>

        </Button>

    </StackPanel>