How to Control Screen Layouts in LightSwitch
- by ChrisD
Visual Studio LightSwitch has a bunch of screen templates that you can use to quickly generate screens. They give you good starting points that you can customize further. When you add a new screen to your project you see a set of screen templates that you can choose from. These templates lay out all the related data you choose to put on a screen automatically for you. And don’t under estimate them; they do a great job of laying out controls in a smart way. For instance, a tab control will be used when you select more than one related set of data to display on a screen. However, you’re not limited to taking the layout as is. In fact, the screen designer is pretty flexible and allows you to create stacks of controls in a variety of configurations. You just need to visualize your screen as a series of containers that you can lay out in rows and columns. You then place controls or stacks of controls into these areas to align the screen exactly how you want.
If you’re new in Visual Studio LightSwitch, you can see this tutorial. OK, Let’s start with a simple example. I have already designed my data entities for a simple order tracking system similar to the Northwind database. I also have added a Search Data Screen to search my Products already. Now I will add a new Details Screen for my Products and make it the default screen via the “Add New Screen” dialog:
The screen designer picks a simple layout for me based on the single entity I chose, in this case Product. Hit F5 to run the application, select a Product on the search screen to open the Product Details Screen. Notice that it’s pretty simple because my entity is simple. Click the “Customize” button in the top right of the screen so we can start tweaking it.
The left side of the screen shows the containership of controls and data bindings (called the content tree) and the right side shows the live preview with data. Notice that we have a simple layout of two rows but only one row is populated (with a vertical stack of controls in this case). The bottom row is empty. You can envision the screen like this:
Each container will display a group of data that you select. For instance in the above screen, the top row is set to a vertical stack control and the group of data to display is coming from Product. So when laying out screens you need to think in terms of containers of controls bound to groups of data. To change the data to which a container is bound, select the data item next to the container:
You can select the “New Group” item in order to create more containers (or controls) within the current container. For instance to totally control the layout, select the Product in the top row and hit the delete key. This will delete the vertical stack and therefore all the controls on the screen. The content tree will still have two rows, but the rows are now both empty.
If you want a layout of four containers (two rows and two columns) then select “New Group” for the data item and then change the vertical stack control to “Two Columns” for both of the rows as shown here:
You can keep going on and on by selecting new groups and choosing between rows or columns. Here’s a layout with 8 containers, 4 rows and 2 columns:
And here is a layout with 7 content areas; one row across the top of the screen and three rows with two columns below that:
When you select Choose Content and select a data item like Product it will populate all the controls within the container (row or column in a vertical stack) however you have complete control on what to display within each group. You can delete fields you don’t want to display and/or change their controls. You can also change the size of controls and how they display by changing the settings in the properties window. If you are in the Screen Designer (and not the customization mode like we are here) you can also drag-drop data items from the left-hand side of the screen to the content tree. Note, however, that not all areas of the tree will allow you to drop a data item if there is a binding already set to a different set of data. For instance you can’t drop a Customer ID into the same group as a Product if they originate from different entities. To get around this, all you need to do is create a new group and content area as shown above.
Let’s take a more complex example that deals with more than just product. I want to design a complex screen that displays Products and their Category, as well as all the OrderDetails for which that product is selected. This time I will create a new screen and select List and Details, select the Products screen data, and include the related OrderDetails. However I’m going to totally change the layout so that a Product grid is at the top left and below that is the selected Product detail. Below that will be the Category text fields and image in two columns below. On the right side I want the OrderDetails grid to take up the whole right side of the screen. All this can be done in customization mode while you’re debugging the application.
To do this, I first deleted all the content items in the tree and then re-created the content tree as shown in the image below. I also set the image to be larger and the description textbox to be 5 rows using the property window below the live preview. I added the green lines to indicate the containers and show how it maps to the content tree (click to enlarge):
I hope this demystifies the screen designer a little bit. Remember that screen templates are excellent starting points – you can take them as-is or customize them further. It takes a little fooling around with customizing screens to get them to do exactly what you want but there are a ton of possibilities once you get the hang of it. Stay tuned for more information on how to create your own screen templates that show up in the “Add New Screen” dialog.
Enjoy!
The tutorial that might be interested:
Adding Custom Control In LightSwitch
