如何在Windows 8中获取窗口标题栏（活动和非活动）颜色？

Question

I'm making a program and I need to paint a rectangle of the same color as the title bar.

If I try to get the color like this:

ARGB rgbActiveColor = GetSysColor(COLOR_ACTIVECAPTION);
ARGB rgbInactiveColor = GetSysColor(COLOR_INACTIVECAPTION);
rgbActiveColor |= 0xFF000000;    // Because of alpha
rgbInactiveColor |= 0xFF000000;

I get a totally different color in Windows 8. It always returns a orange or brown color instead of the actual color (let's say, blue).

Using DwmGetColorizationColor works, but the color is darker because I need to eliminate alpha. I try to do it like this:

BYTE r = ((RED * ALPHA) + (255 * (255 - ALPHA))) / 255; // R' = (R * A) + (1 - A)
BYTE g = ((GREEN * ALPHA) + (255 * (255 - ALPHA))) / 255; // G' = (G * A) + (1 - A)
BYTE b = ((BLUE * ALPHA) + (255 * (255 - ALPHA))) / 255; // B' = (B * A) + (1 - A)

So, my problems are:

1. I don't know how I can correctly convert the return color from ARGB to RGB
2. I don't know how to get the inactive title bar color

EDIT: My ARGB to RGB code seems to work unless I set color intensity in Control Panel to max (because somehow alpha is 0, and the color is green) or min.

EDIT2: This is not a duplicate because this is specifically about W8+.

Answer 1

This is a hackish solution and will probably only work with Windows 8 and 8.1 (I'm going to test later with 10).

I analysed the windows colors and this is what I could see:

• Active window title (or caption) color is the result of blending between 0xD9D9D9 and the color in \\HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\DWM\\ColorizationColor using the value in \\HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\DWM\\ColorizationColorBalance (it's in a 0-100 scale) as a "alpha".
• Inactive windows have the color 0xEBEBEB

So...

if (fActive)
{
    DWORD ColorizationColor;
    DWORD ColorizationColorBalance;
    DWORD size = sizeof(DWORD);

    RegGetValue(HKEY_CURRENT_USER, L"Software\\Microsoft\\Windows\\DWM", L"ColorizationColor", RRF_RT_REG_DWORD, 0, &ColorizationColor, &size);
    RegGetValue(HKEY_CURRENT_USER, L"Software\\Microsoft\\Windows\\DWM", L"ColorizationColorBalance", RRF_RT_REG_DWORD, 0, &ColorizationColorBalance, &size);

    BYTE ALPHA = 255 * ColorizationColorBalance / 100; // Convert from 0-100 to 0-255
    BYTE RED = (ColorizationColor >> 16) & 0xFF;
    BYTE GREEN = (ColorizationColor >> 8) & 0xFF;
    BYTE BLUE = ColorizationColor & 0xFF;

    BYTE r = ((RED * ALPHA) + (0xD9 * (255 - ALPHA))) / 255;
    BYTE g = ((GREEN * ALPHA) + (0xD9 * (255 - ALPHA))) / 255;
    BYTE b = ((BLUE * ALPHA) + (0xD9 * (255 - ALPHA))) / 255;

    graphics.FillRectangle(&SolidBrush(Color(r, g, b)), Rect(...);
}
else
{
    graphics.FillRectangle(&SolidBrush(0xFFEBEBEB), Rect(...));
}

Because this probably won't work at Windows 7 different code should be user for different systems.