向网格添加圆角

Question

I am trying to add a gradient background and rounded corners to a grid. I have the gradient but I can't get the rounded corners to work. This is going to be a status display popup so that is the idea behind it. Also is there a better way to set the gradient?

<UserControl x:Class="TestWPFStatusDisplay.StatusDisplayDialog"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:gif="http://wpfanimatedgif.codeplex.com"
         mc:Ignorable="d"
         d:DesignHeight="154" d:DesignWidth="391">


<Grid>
    <Border Name="mask" Background="White" CornerRadius="7"/>
    <Grid.OpacityMask>
        <VisualBrush Visual="{Binding ElementName=mask}"/>
    </Grid.OpacityMask>

    <Grid.Background>
        <LinearGradientBrush StartPoint="0,0" EndPoint="0,1">
            <GradientStop Color="#ECF5FF" Offset="0"/>
            <GradientStop Color="#9CB0CA" Offset="1"/>
        </LinearGradientBrush>
    </Grid.Background>

    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>

    <Label HorizontalAlignment="Center" Grid.Row="0" Content="Words"/>
    <Image Grid.Row="1" gif:ImageBehavior.AnimatedSource= "Images/GeoCartaLoading.gif" Width="125" Height="50" Margin="25,3,0,0"/>
    <Label Grid.Row="2" Content="Words"/>
    <ProgressBar Grid.Row="3" Name="pb" Maximum="60" />
</Grid>

Answer 1

<Border  CornerRadius="25" BorderBrush="Black" BorderThickness="1">
    <Grid>
        <Button  HorizontalAlignment="Center" VerticalAlignment="Center" Content="content"/>        
    </Grid>
</Border>

Answer 2

This will create a border around your grid with a corner radius (and with a gradient brush):

<Border CornerRadius="3">
    <Border.Background>
        <LinearGradientBrush>
            <!-- Your gradient stops would go here -->
        </LinearGradientBrush>
    </Border.Background>

    <Grid> 
        <!-- Your grid goes here -->
    </Grid>
<Border>