以编程方式更改控件的位置

I have a xaml code like this

我有这样的xaml代码

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="100"/>
        <ColumnDefinition Width="100"/>
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="100"/>
        <RowDefinition Height="100"/>
    </Grid.RowDefinitions>
    <Label Content="Test" Grid.Column="1" Grid.Row="1" Height="100" Width="100" FontSize="20" Name="label"/>
    <Button Content="Change" Grid.Column="0" Grid.Row="0" Click="Button_Click"  />
</Grid>
<G