创建一个与对话框背景色的画刷

HBRUSH hBrush=CreateSolidBrush(GetSysColor(COLOR_BTNFACE)); //对话框背景色

DWORD WINAPI GetSysColor(
  __in  int nIndex
);

Return Value
The function returns the red, green, blue (RGB) color value of the given element.
If the nIndex parameter is out of range, the return value is zero. Because zero is also a valid RGB value, you cannot use GetSysColor to determine whether a system color is supported by the current platform. Instead, use the GetSysColorBrush function, which returns NULL if the color is not supported.

GetSysColor（）返回值为对应nIndex的RGB颜色值