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August 8, 2017
Mobile

Windows 10 SDK Preview Build 16257 and Mobile Emulator Build 15235 Released

Today, we released a new Windows 10 Preview Build of the SDK and the Mobile Emulator to be used in conjunction with Windows 10 Insider Preview (Build 16257 or greater). The Preview SDK Build 16257 contains bug fixes and under development changes to the API surface area.

The Preview SDK and Mobile Emulator can be downloaded from developer section on Windows Insider.

For feedback and updates to the known issues, please see the developer forum.  For new feature requests, head over to our Windows Platform UserVoice.

Things to note:

  • This build works in conjunction with previously released SDKs and Visual Studio 2017.  You can install this SDK and still also continue to submit your apps that target Windows 10 Creators build or earlier to the store.
  • The Windows SDK will now formally only be supported by Visual Studio 2017 and greater. You can download the Visual Studio 2017 here.

Known Issues

  • Designer fails to render: When viewing the XAML in the Designer Window in Visual Studio, the controls fail to render.  This can be resolved by using Visual Studio 2017.3 Preview.
  • Compilation fails on non-Windows 10 platforms 
    When building apps on previous platforms, you may get a build error:

C:\program files (x86)\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll:C:\program files (x860\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll(0,0): Error WMC0621: Cannot resolve ‘GenXbf.dll’ under path ‘C:\program files (x860\Windows Kits\10\bin\10.0.16232.0\x86\genxbf.dll’. Please install the latest version of the Windows 10 Software Development Kit.
Process ‘msbuild.exe’ exited with code ‘1’.

This will occur if the minimum target platform version is set to 10.0.16225.0.  To work around this, right click on your project file and choose properties or open your project file in your favorite editor, and change the version to a previous released SDK.  For example:

[code lang=”xml”]

<WindowsTargetPlatformVersion>10.0.15063.0</WindowsTargetPlatformVersion>

[/code]

  • WRL projects fail to compile with MIDLRT error: When building my WRL project that contains a WinRT Component, the project no longer compiles.  I get the following errors:

midlrt : command line error MIDL1012: [msg]argument illegal for switch / [context]ns_prefix
midlrt : command line error MIDL1000: [msg]missing source-file name

To work around this temporarily you will need to use the previous version of the MidlRT.exe tool.  You can do this by changing your changing your Target Platform Version to a currently installed previous SDK.

[code lang=”xml”]

<WindowsTargetPlatformVersion>10.0.15063</WindowsTargetPlatofrmVersion>

[/code]

Breaking Changes

ecmangen.exe removal from the SDK: ecmangen.exe will no longer ship with the Windows SDK. Developers who rely on ecmangen for event manifest creation are advised to install the Windows Creator Edition of the SDK to obtain the file. Developers may also use notepad or other XML editor of choice for manifest creation. A schema file is available on MSDN to aid in manifest creation, for tools that support it.

API Updates and Additions

When targeting new APIs, consider writing your app to be adaptive in order to run correctly on the widest number of Windows 10 devices. Please see Dynamically detecting features with API contracts (10 by 10) for more information.

The following are the API changes since the 16232 Preview SDK, please reference that list. The TreeView control has been removed, but will be back soon in the next release of Windows and the Preview SDK.

Addition from Preview SDK 16232

[code lang=”csharp”]

namespace Windows.Storage {
public sealed class AppDataPaths
public sealed class SystemDataPaths
public sealed class UserDataPaths
}

[/code]

Removals from Preview SDK 16232

[code lang=”csharp”]

namespace Windows.UI.Xaml.Automation.Peers {
public class TreeViewItemAutomationPeer : ListViewItemAutomationPeer
public class TreeViewListAutomationPeer : SelectorAutomationPeer
}
namespace Windows.UI.Xaml.Controls {
public class TreeView : Control
public sealed class TreeViewExpandingEventArgs
public class TreeViewItem : ListViewItem
public sealed class TreeViewItemClickEventArgs
public class TreeViewList : ListView
public class TreeViewNode : DependencyObject, IBindableIterable, IBindableObservableVector, IBindableVector
public enum TreeViewSelectionMode
public sealed class XamlBooleanToVisibilityConverter : IValueConverter
public sealed class XamlIntegerToIndentationConverter : IValueConverter
}

[/code]