From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Mon, 16 Apr 2012 14:29:59 +0000 (+0000)
Subject: Add default ctor to wxMSW private WindowHDC helper class.
X-Git-Url: https://git.saurik.com/wxWidgets.git/commitdiff_plain/badf8578b234a1f64ce4a9aa3a61b49a7c7210d0?ds=sidebyside

Add default ctor to wxMSW private WindowHDC helper class.

Allow to use objects of this class without any valid HWND, this is useful for
the derived classes which may, or may not, need the corresponding HDC.

See #14194.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71208 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---

diff --git a/include/wx/msw/private.h b/include/wx/msw/private.h
index 2875d294c7..622c3b1544 100644
--- a/include/wx/msw/private.h
+++ b/include/wx/msw/private.h
@@ -417,8 +417,9 @@ private:
 class WindowHDC
 {
 public:
+    WindowHDC() : m_hwnd(NULL), m_hdc(NULL) { }
     WindowHDC(HWND hwnd) { m_hdc = ::GetDC(m_hwnd = hwnd); }
-   ~WindowHDC() { ::ReleaseDC(m_hwnd, m_hdc); }
+   ~WindowHDC() { if ( m_hwnd && m_hdc ) { ::ReleaseDC(m_hwnd, m_hdc); } }
 
     operator HDC() const { return m_hdc; }