Dark scrollbars

[AndnixSH]

Do you know if it's possible to enable dark scrollbars natively in WinForm? Notepad++ and Windows Explorer are using native dark scrollbars

[Aldaviva]

That's a good question. I remember seeing some light scrollbars in WPF but haven't looked at Windows Forms yet. I'll check to see if the Win32 demo has dark scrollbars.

[Aldaviva]

I'm not exactly sure what C++ nonsense this is, but it looks like win32-darkmode is making their native scrollbars dark by wrapping a method from comctl32.dll in FixDarkScrollBar() to force the class name to a different value that gets skinned dark by Windows:

void FixDarkScrollBar()
{
	HMODULE hComctl = LoadLibraryExW(L"comctl32.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
	if (hComctl)
	{
		auto addr = FindDelayLoadThunkInModule(hComctl, "uxtheme.dll", 49); // OpenNcThemeData
		if (addr)
		{
			DWORD oldProtect;
			if (VirtualProtect(addr, sizeof(IMAGE_THUNK_DATA), PAGE_READWRITE, &oldProtect))
			{
				auto MyOpenThemeData = [](HWND hWnd, LPCWSTR classList) -> HTHEME {
					if (wcscmp(classList, L"ScrollBar") == 0)
					{
						hWnd = nullptr;
						classList = L"Explorer::ScrollBar";
					}
					return _OpenNcThemeData(hWnd, classList);
				};

				addr->u1.Function = reinterpret_cast<ULONG_PTR>(static_cast<fnOpenNcThemeData>(MyOpenThemeData));
				VirtualProtect(addr, sizeof(IMAGE_THUNK_DATA), oldProtect, &oldProtect);
			}
		}
	}
}

I have no idea how to do this in C#, but I might try to give it a shot.

[memoarfaa]

@AndnixSH
@Aldaviva
To enable dark scrollbars natively in WinForm you need to use "SetWindowTheme" function
https://learn.microsoft.com/en-us/windows/win32/api/uxtheme/nf-uxtheme-setwindowtheme

[DllImport("uxtheme.dll", SetLastError = true, ExactSpelling = true, CharSet = CharSet.Unicode)]
public static extern int SetWindowTheme(IntPtr hWnd, string pszSubAppName, string pszSubIdList);

SetWindowTheme(control.Handle, "DarkMode_Explorer", "ScrollBar");

example to dark scrollbar and treeView

https://www.mediafire.com/file/4m0uieavnkityje/DarkWinForm.zip/file

[Aldaviva]

Oh wow thanks, that's way easier than the win32-darkmode C++ function wrapping technique.

I'll try to see if there's a good way to handle this automatically in this library, but at the very least, this method can be called manually (either directly by the dependent UI app, or proxied by this library for convenience).

[memoarfaa]

@Aldaviva
Can you support Dark built in ScrollBar of MdiClient and Dark TreeView

Controls.Cast<Control>().ToList().ForEach(control =>
            {
                if (control.GetType().Name == nameof(MdiClient))
                {
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "ScrollBar");
                }
                else if(control.GetType().Name == nameof(TreeView))
                {
                   control.ForeColor = Color.White;
                   control..BackColor = Color.FromArgb(25, 25, 25);
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "TreeView");
                }

            });

2023-08-20_20-22-57.mp4

[Aldaviva]

Thanks, let me try that out! I'm definitely not a Forms expert so I appreciate the assistance.

[AndnixSH]

@memoarfaa that's nice. Would it support buttons, textboxes and dropdowns too, like how Notepad++ and foobar2000 implemented them?

[memoarfaa]

@Aldaviva
@AndnixSH

[DllImport("user32.dll", CharSet = CharSet.Auto)]
 public static extern IntPtr SendMessage(IntPtr hWnd, int msg, int wParam, int lParam);

  Controls.Cast<Control>().ToList().ForEach(control =>
            {
                if (control.GetType().Name == nameof(MdiClient) | control.GetType().BaseType.Name == nameof(ScrollBar))
                {
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "ScrollBar");
                    // Fix scrollbar corners and TreeView borders not repainting with the new theme
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }
                else if(control.GetType().Name == nameof(TreeView))
                {
                    control.ForeColor = Color.White;
                    control.BackColor = Color.FromArgb(25, 25, 25);
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "TreeView");
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }
                else if (control.GetType().Name == nameof(Button))
                {
                   
                    ((Button)control).FlatStyle = FlatStyle.System;
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "Button");
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }

                else if (control.GetType().Name == nameof(TextBox))
                {
                    control.ForeColor = Color.White;
                    SetWindowTheme(control.Handle, "DarkMode_InActiveAddressComposited", "Edit");
                    // Another Dark Theme for Edit
                   // SetWindowTheme(control.Handle, "DarkMode_CFD", "Edit");
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }
                
                else if (control.GetType().Name == nameof(CheckBox))
                {
                    ((CheckBox)control).FlatStyle = FlatStyle.System;
                    SetWindowTheme(control.Handle, "DarkMode_Explorer", "CheckBox");
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }
                
                else if (control.GetType().Name == nameof(ComboBox))
                {
                    control.ForeColor = Color.White;
                    control.BackColor = Color.FromArgb(19,19,19);
                    SetWindowTheme(control.Handle, "DarkMode_CFD", "ComboBox");
                    // Another Dark Theme for ComboBox
                    // SetWindowTheme(control.Handle, "DarkMode_AddressComposited", "ComboBox");
                    SendMessage(control.Handle, WM_THEMECHANGED, 0, 0);
                }
              

            });

[Aldaviva]

Nice, I'll take a look at that.