GDI+ 和MFC内存泄露检测

原文地址：http://www.codeproject.com/KB/GDI-plus/gdiplush.aspx

绪论

当我开始使用VC++6.0进行GDI+和MFC编程后，我遇到了一些麻烦的问题：

1. 不移除DEBUG_NEW 宏就不能编译有MFC的GDI代码
2. 不少许修改代码就不能编译有STL的GDI+代码
3. 不能探测到内存泄露

以下是解决方案

怎样使用

在stdafx.h文件中包含 GdiplusH.h

// GDI+ helper file

#include "GdiplusH.h"

特征

• 程序启动时候将初始化GDI+
• 你可以使用函数_CrtXXX来检查内存泄露，设置一个断点，保存并且比较内存状态，等等
• 内存泄露信息将在（VC）窗口输出
• 没有DEBUG_NEW方面的编译问题
• 没有STL方面的编译问题

内存泄露检查

GDI+使用GdipAlloc和GdipFree为GDI+对象分配内存。大概它们在gdiplus.dll有自己的内存分配表，但不幸的是，那没有输出API去得到内存泄露信息。GDI+对象能在栈上定位（例：在函数中创建一个局部变量），这些内存区域没有设置初始值，所以我们可以不使用GdipAlloc或者GdipFree函数。如果我们调用CRT调试内存分配和释放函数的版本代替GdipAlloc/Free，我们使用有名的_CrtXXX 函数可以十分容易地侦测到内存的泄露。

 

多种定义

 

• GDIPLUS_NO_AUTO_INIT - GDI+在程序启动时候不会被初始化。你可以创建一个GdiPlus::GdiPlusInitialize变量来初始化GDI+（GDI+将在析构函数调用这个变量时候被初始化）。
•  GDIPLUS_USE_GDIPLUS_MEM - GdipAlloc和GdipFree用于内存操作。在这种情况下_Crt函数不能用于检查内存的泄露。
•  GDIPLUS_NO_AUTO_NAMESPACE - Gdiplus名字空间将不作为一个使用的命名空间定义。所以在这种情况下你必须得使用Gdiplus::前缀。

致谢

• http://www.codeproject.com/vcpp/gdiplus/vc6gdiplusmacro.asp
• http://www.codeproject.com/vcpp/gdiplus/imageexgdi.asp?df=100&forumid=3203&select=465515#xx465515xx

 

 

后面附带原文，望大家予以斧正！在下先谢谢了！！

 

 

 

 

GDI+ and MFC memory leak detection

Introduction

When I started to use GDI+ with MFC in VC++ 6.0 I ran into some annoying problems:

1. Couldn't compile my GDI+ code with MFC without removing the DEBUG_NEW macros
2. Couldn't compile GDI+ code with STL without tweaking my code
3. Couldn't detect memory leaks

Here is the solution!

Here is the solution!

How to use

Include GdiplusH.h in stdafx.h:

Collapse Copy Code

// GDI+ helper file

#include "GdiplusH.h"

Features

• GDI+ will be initialized when program starts
• You can use _CrtXXX functions to detect memory leaks, set an allocation breakpoint, save and compare memory states, etc.
• Memory leak information will be dumped to output window (MSVC IDE)
• No more compilation problem with DEBUG_NEW
• No more compilation problem with STL

Memory leak detection

 

GDI+ is using GdipAlloc and GdipFree for allocating memory for GDI+ objects. Probably they have their own memory allocation lists in gdiplus.dll, but unfortunately there is no exported API to get any memory leak information. But GDI+ objects can be located on stack (for example: creating a local variable in a function), so there is no special initialization for these memory regions, so we do not have to use GdipAlloc or GdipFree. If we call the CRT debug version of memory allocation and deletion functions instead of GdipAlloc/Free, we can detect memory leaks very easily using the well known _CrtXXX functions.

 

Miscellaneous defines

 

• GDIPLUS_NO_AUTO_INIT - GDI+ won't be initialized at program startup. You have to create aGdiPlus::GdiPlusInitialize variable to initialize GDI+ (GDI+ will be uninitialized, when destructor is called for this variable).
•  GDIPLUS_USE_GDIPLUS_MEM - GdipAlloc and GdipFree is used for memory operations. In this case _Crt functions cannot be used to detect memory leaks
•  GDIPLUS_NO_AUTO_NAMESPACE - Gdiplus namespace won't be defined as a used namespace. In this case you have to use Gdiplus:: prefix.

Acknowledgements

• http://www.codeproject.com/vcpp/gdiplus/vc6gdiplusmacro.asp
• http://www.codeproject.com/vcpp/gdiplus/imageexgdi.asp?df=100&forumid=3203&select=465515#xx465515xx