实现编辑框输入光标颜色修改

响应SetFocus消息:添加下面代码
//CBitmap bmp;非局部变量
        bmp.DeleteObject();
	CDC mdc;
	CDC * dc = CDC::FromHandle(::GetWindowDC(::GetDesktopWindow()));
	mdc.CreateCompatibleDC(dc);
	bmp.CreateCompatibleBitmap(dc,2,30);

	CDC * edit_dc = mEdit1.GetWindowDC();
	COLORREF clr = edit_dc->GetPixel(CPoint(2,2));//获取背景色
	{
		BYTE r = clr&0xff;
		BYTE g = (clr>>8)&0xff;
		BYTE b = (clr>>16)&0xff;

		clr = RGB(255-r,255-g,255-b);//颜色反转
	}

	HBITMAP holdbmp = (HBITMAP)mdc.SelectObject(bmp);
	mdc.FillSolidRect(0,0,3,30,clr);

	HBITMAP hBmpNew = (HBITMAP)mdc.SelectObject(holdbmp);


	mEdit1.CreateCaret(CBitmap::FromHandle(hBmpNew));
	mEdit1.ShowCaret();
	mdc.DeleteDC();