UWP News - The UWP Community Toolkit Cheese Has Moved

Hello UWP App Dev peeps!

If you've been following along with my UWP Community Toolkit tips, you may have noticed a few of the links are either dead or redirecting to other pages. This is happening because all UWP Community Toolkit information and documentation can now be found on docs.microsoft.com. Docs is now the home for all things documentation in the Microsoft development world, in case you haven't heard. The many of the old links on developer.microsoft.com are now redirecting to Docs.

I will be going back through my blog posts over the next couple of weeks to update links. Until that time, if you encounter a dead link, feel free to leave a comment on the post or reach out to me on Twitter. You can use the excellent search feature on docs.microsoft.com to find the docs for all the UWP Toolkit features and APIs.

The code itself still lives over on GitHub. Use this site to report issues, request enhancements or contribute to the toolkit yourself through a PR. You can also contribute to the documentation on the Docs site if you find anything missing, lacking depth, or altogether incorrect.

Thanks again for following along with the UWP App Dev Tips! You can expect to see a new tip in the next couple of days.


Cheers!

UWP Tip #8 - UWP Community Toolkit - Part 6, Using the VisualTree and LogicalTree UI Helpers

Welcome back to the UWP Community Toolkit series. Previous Tips in the UWP Community Toolkit series:

• Part 1, What's in the Box?
• Part 2, Consuming the Services
• Part 3, Leveraging Code Helpers (Color, Connection, Converters and ImageCache)
• Part 4, Leveraging the StorageFiles and Storage Code Helpers
• Part 5, Using the Streams Code Helper

Introduction

This tip will continue exploring the Code Helpers that we started looking at in Part 3. There are only a few types of helpers remaining, and today we will examine the collection of available VisualTree and LogicalTree UI extension methods.

VisualTree Extensions

The VisualTree extension methods extend and simplify the built-in UI element navigation methods of the framework. There are currently five methods available to use in the toolkit.

• FindDescendantByName(elementName) - Navigates down the visual tree until an element with the provided name is found.
• FindDescendant<T>() - Navigates down the visual tree and returns the first element for the given type.
• FindDescendants<T>() - Returns an IEnumerable of all descendant elements of the given type.
• FindAscendantByName(elementName) - Navigates up the visual tree until an element with the provided name is found.
• FindAscendant<T>() - Navigates up the visual tree and returns the first element for the given type.

Here is an example of the use of each method to retrieve UI elements from your visual tree.

public void ProcessVisualUiElements()
{
    var listControl = mainGrid.FindDescendantByName("resultList");

     listControl = mainGrid.FindDescendant<ListView>();

     listControl.MaxWidth = 500;

     foreach (var item in mainGrid.FindDescendants<ListViewItem>())
    {
        item.IsEnabled = false;
    }

     var gridControl = resultList.FindAscendantByName("mainGrid");

     gridControl = resultList.FindAscendant<Grid>();

     gridControl.Margin = new Thickness() { Bottom = 2, Left = 2, Right = 2, Top = 4 };
}

Most UWP developers will probably use the FindAscendant/FindDescendant methods using the type of element to find as we try to avoid naming our UI elements.

LogicalTree Extensions

The LogicalTree extensions are very similar but they operate over logical elements, ignoring certain containers and style elements only found in the visual tree. Not having to rely on knowing if the elements have been rendered yet before finding them can be an advantage of this method also.
The set of methods available mirror those for the visual tree with one additional method to find an element's content control.

• FindChildByName(elementName)
• FindChild<T>()
• FindChildren<T>()
• FindParentByName(elementName)
• FindParent<T>()
• GetContentControl()

The sample code also mirrors the previous sample.

public void ProcessLogicalUiElements()
{
    var listControl = mainGrid.FindChildByName("resultList");
    
    listControl = mainGrid.FindChild<ListView>();
    
    foreach (var item in resultList.FindChildren<ListViewItem>())
    {
        item.IsEnabled = true;
    }
    
    var gridControl = resultList.FindParentByName("mainGrid");
    
    gridControl = resultList.FindParent<Grid>();
    
    var searchContent = searchTextBox.GetContentControl();
}

Wrap-Up

That's all for today's helpers! They're very straightforward to use and can save quite a bit of manually traversing the visual and logical trees to find a target element. Check back as next time we will finish up the helpers provided by the UWP Community Toolkit.
Happy coding!

del.icio.us Tags: uwp community toolkit,uwp,xaml

UWP News - UWP in FCU Supports .NET Standard 2.0

Big news this week for UWP developers. If your app is targeting Windows 10.0.16299 (the Fall Creators Update), you can now access ~20,000 APIs that were added as part of .NET Standard 2.0.

The announcement was made during Windows Developer Day on Tuesday, and a .NET Blog post by Rich Lander and Immo Landwerth dives into some of the details.

In order to use .NET Standard 2.0 in UWP, you need to target Fall Creators Update (FCU) as the minimum version of your UWP project. That’s because .NET Standard 2.0 contains many APIs that require FCU to make them work in the context of the UWP execution environment, specifically AppContainer.

To get started, go upgrade to the Fall Creators Update, get the new Windows SDK and the new build of Visual Studio 2017 (v15.4). Get started building new UWP apps or updating your existing apps to support the FCU features and .NET Standard 2.0. Microsoft is offering some great prizes in a new contest to encourage Windows developers to target the FCU, including a Surface Studio. Get the contest details here.

Landwerth has also updated his .NET Standard Selector website to include .NET Standard and UWP. If you are unsure of which platforms are supported by each version of .NET Standard, check out this handy reference.

Happy coding!