Merge pull request #5592 from TerryGLee/tglee-include

add new programming language control INCLUDE file

Author: ShannonLeavitt

docs/ide/includes/devlang-control.md

@@ -0,0 +1,9 @@
+---
+author: TerryGLee
+ms.prod: visual-studio-windows  
+ms.topic: include
+ms.date: 10/11/2019
+ms.author: tglee
+---
+> [!IMPORTANT]
+> Use the programming language control at the top right of this page to view either the C# code snippet or the Visual Basic code snippet.<br><br>![Programming language control for Docs.Microsoft.com](../media/docs-programming-language-control.png)

docs/ide/step-6-name-your-button-controls.md

@@ -59,8 +59,7 @@ You can verify the names by choosing the control selector drop-down list in the
     End Sub
     ```
 
-   > [!IMPORTANT]
-   > Use the programming language control at the top right of this page to view either the C# code snippet or the Visual Basic code snippet.<br><br>![Programming language control for Docs.Microsoft.com](../ide/media/docs-programming-language-control.png)
+   [!INCLUDE [devlang-control](./includes/devlang-control.md)]
 
    You're looking at code called `showButton_Click()` (alternatively, `ShowButton_Click()`). The IDE added this to the form's code when you opened the code file for the **showButton** button. At design-time, when you open the code file for a control in a form, code is generated for the control if it doesn't already exist. This code, known as a *method*, runs when you run your app and choose the control - in this case, the **Show a picture** button.