WPF Grid horizontalalignment不起作用。(WPF Grid horizontalalignment doesn't work. Sizes don't changes)

 我有一个Stack，我在Stack里面有一个Grid。 
 
 我调整窗口大小时需要增加堆栈和网格大小。 我将Stack和Grid Horizo​​ntalAlignment设置为'Stretch' 
 
 堆栈工作正常，但我调整窗口大小时网格大小不会上升 
 
 这是我的代码。 
 
<StackPanel Background="Blue" Orientation="Horizontal" HorizontalAlignment="Stretch" Grid.Column="1" Margin="13,0,0,0" >
   <Grid HorizontalAlignment="Stretch" Background="Beige" Width="515">

        <Grid.RowDefinitions>
            <RowDefinition Height="100" />
            <RowDefinition Height="240" />
            <RowDefinition Height="100" />
        </Grid.RowDefinitions>

        <Image x:Name="imageMap" Source="Resources/images.jpg" HorizontalAlignment="Stretch" Grid.Row="0" Stretch="Fill" Margin="0,0,0,0" />

   </Grid>
</StackPanel>
 
 请指教 

I have a Stack and I have a Grid inside of Stack.
 
I need to increase Stack and Grid sizes when I resize the window. I set Stack and Grid HorizontalAlignment to 'Stretch'
 
Stack works fine but grid sizes don't raises when I resize the window
 
This is my code.
 
<StackPanel Background="Blue" Orientation="Horizontal" HorizontalAlignment="Stretch" Grid.Column="1" Margin="13,0,0,0" >
   <Grid HorizontalAlignment="Stretch" Background="Beige" Width="515">

        <Grid.RowDefinitions>
            <RowDefinition Height="100" />
            <RowDefinition Height="240" />
            <RowDefinition Height="100" />
        </Grid.RowDefinitions>

        <Image x:Name="imageMap" Source="Resources/images.jpg" HorizontalAlignment="Stretch" Grid.Row="0" Stretch="Fill" Margin="0,0,0,0" />

   </Grid>
</StackPanel>
 
Please advise

原文：https://stackoverflow.com/questions/27274438