一、下载图标文件 

iconfont-阿里巴巴矢量图标库

二、xaml界面代码编辑

文件结构

           对应的图标代码

Fonts/#iconfont   对应文件位置

<Window.Resources><ControlTemplate TargetType="Button" x:Key="CloseButtonTemplate"><Grid Background="Transparent" Name="back"><TextBlock Text="&#xe653;" FontFamily="Fonts/#iconfont" VerticalAlignment="Center" HorizontalAlignment="Center" FontSize="14"/></Grid><ControlTemplate.Triggers><Trigger Property="IsMouseOver" Value="True"><Setter Property="Background" Value="red" TargetName="back"/></Trigger></ControlTemplate.Triggers></ControlTemplate>
</Window.Resources>

<Grid ShowGridLines="True"><Grid.RowDefinitions><RowDefinition Height="30" /><RowDefinition Height="30"/><RowDefinition Height="50"/></Grid.RowDefinitions><Button HorizontalAlignment="Right" Content="X" Margin="0,0,0,0" Width="60" Height="30" BorderThickness="0" Template="{StaticResource CloseButtonTemplate}"/></Grid>