Preventing Registry.GetValue overflow

Question

I'm trying to get the DWM colorizationColor using: Microsoft.Win32.Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\DWM").GetValue("ColorizationColor")

however it is returning -2144154163 (the real value is 2150813133)

I thinks this is because the value cannot be hold on a 32-bit int... however event casting (or Converting) to int64 fails.

PD: It may sound like an easy question to answer but I cannot find a solution :(

Answer 1

Color values are pretty impractical as int values, it is best to convert it quickly. A little wrapper to dispose the key doesn't hurt either:

using System.Drawing;
...
        public static Color GetDwmColorizationColor() {
            using (var key = Microsoft.Win32.Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\DWM")) {
                return Color.FromArgb((int)key.GetValue("ColorizationColor"));
            }
        }

But don't do it this way, there's a documented API for it. P/Invoke DwmGetColorizationColor() to get the value, you'll get guaranteed compatibility behavior. Important if some future Windows version changes this registry details. Visit pinvoke.net for the declaration.

Answer 2

You need to make an unchecked cast:

unchecked {
    value = (uint)intValue;
}

EDIT: Registry.GetValue returns an object containing a boxed Int32 value.
You cannot unbox the value and cast to a different value type in a single cast.

When casting directly from object, you need to first unbox it to its actual type, then cast it to uint:

unchecked {
    value = (uint)(int)boxedObject;
}