gdiplus exception

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<span style="font-size:14px;">#include <windows.h>#include <gdiplus.h>#include <stdio.h>using namespace Gdiplus;#pragma comment(lib, "gdiplus.lib")int main(){GdiplusStartupInput gdiplusStartupInput;ULONG_PTR gdiplusToken;GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);printf("%d\n", gdiplusStartupInput.GdiplusVersion);Image image(L"ing.png");printf("The width of the image is %u.\n", image.GetWidth());printf("The height of the image is %u.\n", image.GetHeight());GdiplusShutdown(gdiplusToken);return 0;}</span>

一个使用Gdiplus的Hello World程序，居然都出现了错误。输出居然没有问题=)。

因为这学期到下学期打算深入学习调试技术，一心想着不丢弃所遇到的任何一个bug。

F5跟踪一下：

在Image类的析构函数中出现一个Access violation 错误。

析构函数一般都是用来释放空间的，为什么会出错呢？

自认为很重要的一点：在main函数return语句没执行之前调用的Image类的析构函数。

回想下看MSDN GdiplusStartup、GdiplusShutdown里的一句话：

Remarks

You must call GdiplusStartup before you create any GDI+ objects, and you must delete all of your GDI+ objects (or have them go out of scope) before you call GdiplusShutdown.

也就是说我们在调用GdiplusShutdown以后再去delete某个对象，造成了这个Access violation错误。

解决办法：

<span style="font-size:14px;">#include <windows.h>#include <gdiplus.h>#include <stdio.h>using namespace Gdiplus;#pragma comment(lib, "gdiplus.lib")int main(){GdiplusStartupInput gdiplusStartupInput;ULONG_PTR gdiplusToken;GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);{Image image(L"ing.png");printf("The width of the image is %u.\n", image.GetWidth());printf("The height of the image is %u.\n", image.GetHeight());}GdiplusShutdown(gdiplusToken);return 0;}</span>

把gdi+处理函数放在一个{}内

或者

<span style="font-size:14px;">#include <windows.h>#include <gdiplus.h>#include <stdio.h>using namespace Gdiplus;INT main(){   GdiplusStartupInput gdiplusStartupInput;   ULONG_PTR gdiplusToken;   GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);   Image *image = new Image(L"ing.png");   printf("The width of the image is %u.\n", image->GetWidth());   printf("The height of the image is %u.\n", image->GetHeight());    delete image;   GdiplusShutdown(gdiplusToken);   return 0;}</span>

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