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Setting wallpaper through Active Desktop in UWP app changes fit mode

I am using the Active Desktop interface in C# to change desktop wallpaper in Windows. I am only using the IActiveDesktop.SetWallpaper method and never use IActiveDesktop.SetWallpaperOptions, so I would expect only the wallpaper image to change and not its fit (tile, stretch, fill, etc.).
When I my compile my code as a .NET desktop app, this behaves as expected. However, when I use Desktop Bridge to compile my app as a UWP app for the Windows Store, the wallpaper fit changes and not just the image. I don't understand why running my code as a UWP app should make the Active Desktop interface behave any differently.
For example, if I select "Span" in the Windows 10 Settings app to make the wallpaper stretch across my two monitors, my UWP app does not respect this setting. When it changes the wallpaper image, the fit also changes to show the image separately on each monitor. But the .NET desktop version of my app respects the wallpaper fit setting and does not change it.
I have included the relevant part of my code below. The entire file can be found here.
[ComImport]
[Guid("F490EB00-1240-11D1-9888-006097DEACF9")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IActiveDesktop
{
[PreserveSig]
int ApplyChanges(AD_Apply dwFlags);
[PreserveSig]
int SetWallpaper([MarshalAs(UnmanagedType.LPWStr)] string pwszWallpaper, int dwReserved);
}
public class WallpaperChanger
{
public static readonly Guid CLSID_ActiveDesktop =
new Guid("{75048700-EF1F-11D0-9888-006097DEACF9}");
public static IActiveDesktop GetActiveDesktop()
{
Type typeActiveDesktop = Type.GetTypeFromCLSID(WallpaperChanger.CLSID_ActiveDesktop);
return (IActiveDesktop)Activator.CreateInstance(typeActiveDesktop);
}
public static void SetWallpaper(string imagePath)
{
IActiveDesktop iad = GetActiveDesktop();
iad.SetWallpaper(imagePath, 0);
iad.ApplyChanges(AD_Apply.ALL | AD_Apply.FORCE | AD_Apply.BUFFERED_REFRESH);
}
}
Note: I've tried using the SetWallpaperAsync function available in the Windows UWP library, and it has the same problem. Also this problem is not specific to multiple monitors, the same thing happens with just a single one.

How do I arrange or sort the desktop icons in c#?

You know when you right-click the desktop and there's a "Sort by" option that allows you to sort the icons by "Name", "Size", "Item Type", or "Date Modified"? Well, I want to find a way to sort the desktop's icons with a push of a button.
I saw a similar question being asked here on stackoverflow but it's old and the code didn't work for me. The link to the question is: Arranging desktop icons with C# . I'm trying to achieve this in Windows 10.
There was a comment on there that said that the LVM_* and LVA_* values are stored in the commctrl.h file which comes with the SDK. I couldn't find that file for some reason.
Here's what i'm using:
//sort desktop
public const int LVM_ARRANGE = 4118;
public const int LVM_ALIGNLEFT = 1;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
//end of sort desktop
private void organizeBtn_Click(object sender, EventArgs e)
{
var DesktopHandle = GetDesktopWindow();
MessageBox.Show(GetDesktopWindow().ToString());
SendMessage(GetDesktopWindow(), LVM_ARRANGE, LVM_ALIGNLEFT, 0);
}
I've been digging for info or some sort of direction about this topic, especially regarding windows 10, but I can't find much. Please help?

In Windows 10, the desktop (not tile world!) is still a SysListView32, but the GetDesktopWindow API call will return the handle of its grandparent, a Progman window - reminiscence of the ancient "Program Manager" of Windows 3.0. Then there is a shim of the SHELLDLL_DefView class, and below that you find buried the listview you're after.
Use the information from this answer to move down from the shell window to the folder view, which you can eventually send the LVM_ARRANGE message.
This is a brittle approach, as it relies on undocumented properties of the operating system, which may change at any time with updates or new versions. It will probably break also when a user uses a slideshow as desktop background, because Windows then rearranges the desktop window stack. Hack to deal with this here.
Another approach which is documented and less likely to break in future versions, with the downside of involving COM and a nightmare from C#, is via the IFolderView of shell automation, two relevant finds here and here.

Language Bar change language in c# .NET

TL;DR: Trying to solve the issue that InputLanguage changes the input layout but does not update the Language Bar display.
I am writing a custom plugin for Trados Studio. Part of this is interfacing with languages both in the app itself and in Word, as in this question: List of all available languages for Windows .NET framework
The last problem I seem to cannot solve is that in a part of the code I am using InputLanguage to set the keyboard input to en-US.
To clarify, there is a limited API, so I have to be really inventive in automating certain aspects. The best workable approach was to use the default shortcuts in the application:
First I change the input language to en-US.
Then I send some keys to the application.
Then I change the input language back to what it was before.
Then I show a form.
Here is the code:
//change input language to English
InputLanguage currentLang = InputLanguage.CurrentInputLanguage;
InputLanguage newLang = InputLanguage.FromCulture(System.Globalization.CultureInfo.GetCultureInfo("en-US"));
if (newLang == null)
{
MessageBox.Show("The Upload Project function requires the En-US keyboard installed.", "Missing keyboard", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
else
{
InputLanguage.CurrentInputLanguage = newLang;
}
//Save the document
SendKeys.SendWait("^s");
InputLanguage.CurrentInputLanguage = currentLang;
//get url and credentials from a custom input form
string[] psw = UploadData.GetPassword(
Settings.GetValue("Upload", "Uri", "https://www.scntranslations.org/ws/services"),
Vars.wsUsername == null ? Settings.GetValue("Upload", "User", "") : Vars.wsUsername,
Vars.wsPassword == null ? "" : Vars.wsPassword
);
Application.DoEvents();
The manifestation that I have is that the Language Bar changes with a delay to EN but by the time the form shows up it should be HU yet it stays EN.
However if I test it with Debug.WriteLine(InputLanguage.CurrentInputLanguage.LayoutName) then the output is the correct language (in my case "Hungarian").
Even after the form is hidden, the language remains EN, yet the keyboard types in Hungarian and the Debug.WriteLine(InputLanguage.CurrentInputLanguage.LayoutName) returns "Hungarian".
I looked at dozens of pages on SO and the web and I tried everything I could think of including System.Threading.Thread.Sleep(1000); and Application.DoEvents() and Sendkeys.Flush(), but nothing triggers Windows to update the Language Bar, and I could not find any solution to this issue.
The earlier version of this problem as given in this question: Change keyboard layout from C# code with .NET 4.5.2
I have made this work now fully with the above implementation of the InputLanguage bar this last hick-up.
Can anybody help in:
giving an explanation for this behavior?
suggesting a solution that triggers the update of the Language Bar from C# code?
UPDATE: The code now fully works. I implemented the BlockInput WinAPI.
[System.Runtime.InteropServices.DllImportAttribute("user32.dll", EntryPoint = "BlockInput")]
[return: System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)]
public static extern bool BlockInput([System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)] bool fBlockIt);
And also turning off the Caps Lock using Win API:
[DllImport("user32.dll")]
public static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);
private void TurnOffCapsLock()
{
if (Control.IsKeyLocked(Keys.CapsLock)) // Checks Capslock is on
{
const int KEYEVENTF_EXTENDEDKEY = 0x1;
const int KEYEVENTF_KEYUP = 0x2;
NativeMethods.keybd_event(0x14, 0x45, KEYEVENTF_EXTENDEDKEY, (UIntPtr)0);
NativeMethods.keybd_event(0x14, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
(UIntPtr)0);
}
}
So what's left really is getting the Language Bar to correctly show the actual current input language.
I do have the option of sending Alt+Shifts, but I really don't want to do that.

How do I detect if a Windows device is touch-enabled

How do I detect if a device is touch-enabled in C# for a WinForms app (Not WPF).
I found information on GetSystemMetrics. But I can't find how to use this in C#.
I tried using System.Windows.Input.Tablet class. But it's not coming up in C#, even though I am using .NET Framework 4.5.
I tried using System.Windows.Devices. But it's not coming up in C#, even though I am using .NET Framework 4.5.
I have also checked Detect whether a Windows 8 Store App has a touch screen and How to detect a touch enabled device (Win 8, C#.NET), which would seem to make this question a duplicate. However, neither of these answers my question.

GetSystemMetrics seems to be the right way to go. It should be accessed through P/Invoke like this:
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern int GetSystemMetrics(int nIndex);
public static bool IsTouchEnabled()
{
const int MAXTOUCHES_INDEX = 95;
int maxTouches = GetSystemMetrics(MAXTOUCHES_INDEX);
return maxTouches > 0;
}

As taken from this answer
var hasTouch = Windows.Devices.Input
.PointerDevice.GetPointerDevices()
.Any(p => p.PointerDeviceType == Windows.Devices.Input.PointerDeviceType.Touch);

Getting UI text from external app in C#

Is it possible to get UI text from an external application in C#.
In particular, is there a way to read Unicode text from a label (I assume it's a normal Windows label control) from an external Win32 app that was written by a 3rd party? The text is visible, but not selectable by mouse in the UI.
I assume there is some accessibility API (e.g. meant for screen readers) that allows this.
Edit: Currently looking into using something like the Managed Spy App but would still appreciate any other leads.

If you just care about the standard Win32 label, then WM_GETTEXT will work fine, as outlined in the other answers.
--
There is an accessibility API - UIAutomation - for standard labels, it too uses WM_GETTEXT behind the scenes. One advantage to it, however, is that it can get text from several other types of controls, including most system controls, and often UI using non-system controls - including WPF, text in IE and Firefox, and others.
// compile as:
// csc file.cs /r:UIAutomationClient.dll /r:UIAutomationTypes.dll /r:WindowsBase.dll
using System.Windows.Automation;
using System.Windows.Forms;
using System;
class Test
{
public static void Main()
{
// Get element under pointer. You can also get an AutomationElement from a
// HWND handle, or by navigating the UI tree.
System.Drawing.Point pt = Cursor.Position;
AutomationElement el = AutomationElement.FromPoint(new System.Windows.Point(pt.X, pt.Y));
// Prints its name - often the context, but would be corresponding label text for editable controls. Can also get the type of control, location, and other properties.
Console.WriteLine( el.Current.Name );
}
}

You could do it if that unicode text is actually a window with a caption by sending a WM_GETTEXT message.
[DllImport("user32.dll")]
public static extern int SendMessage (IntPtr hWnd, int msg, int Param, System.Text.StringBuilder text);
System.Text.StringBuilder text = new System.Text.StringBuilder(255) ; // or length from call with GETTEXTLENGTH
int RetVal = Win32.SendMessage( hWnd , WM_GETTEXT, text.Capacity, text);
If it is just painted on the canvas you might have some luck if you know what framework the application uses. If it uses WinForms or Borland's VCL you could use that knowledge to get to the text.

didn't see the values for wm_gettext or wm_gettextlength in that article, so just in case..
const int WM_GETTEXT = 0x0D;
const int WM_GETTEXTLENGTH = 0x0E;