Create MainWindow.xaml

src/MainWindow.xaml

@@ -0,0 +1,38 @@
+<Window x:Class="LanguageEditor.MainWindow" 
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:local="clr-namespace:LanguageEditor"
+        Title="Language Editor"
+        Height="606" Width="800"
+        WindowStartupLocation="CenterScreen"
+        UseLayoutRounding="True" SnapsToDevicePixels="True" TextOptions.TextFormattingMode="Display"
+        Closing="Window_Closing">
+    <Grid>
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="*"/>
+        </Grid.ColumnDefinitions>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+        </Grid.RowDefinitions>
+        <Menu Background="Transparent" Grid.Column="0" Grid.Row="0" Padding="2">
+            <MenuItem Header="_File">
+                <MenuItem x:Name="fileOpen" Header="_Open..." Click="fileOpen_Click"/>
+                <Separator/>
+                <MenuItem x:Name="fileClose" Header="_Close" Click="fileClose_Click"/>
+                <Separator/>
+                <MenuItem x:Name="fileSave" Header="_Save" Click="fileSave_Click"/>
+                <MenuItem x:Name="fileSaveAs" Header="Save _As..." Click="fileSaveAs_Click"/>
+                <Separator/>
+                <MenuItem x:Name="fileExit" Header="E_xit" Click="fileExit_Click"/>
+            </MenuItem>
+        </Menu>
+        <ContentControl Content="{Binding Path=File}" Grid.Column="0" Grid.Row="1">
+            <ContentControl.Resources>
+                <DataTemplate DataType="{x:Type local:LanguageFile}">
+                    <local:LanguageControl/>
+                </DataTemplate>
+            </ContentControl.Resources>
+        </ContentControl>
+    </Grid>
+</Window>