高手帮我看看这段代码，为什么会出现访问内存违例？急急急

[aatny1]

平台:C++ builder6.

头文件：test.h

//---------------------------------------------------------------------------

#ifndef testH
#define testH
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>

//#include "RzPanel.hpp"
#include <vector.h>
//---------------------------------------------------------------------------
class MyPanel;
class TForm1 : public TForm
{
__published: // IDE-managed Components
TButton *Button1;
TButton *Button2;
void __fastcall Button1Click(TObject *Sender);
void __fastcall Button2Click(TObject *Sender);
private: // User declarations
public: // User declarations
__fastcall TForm1(TComponent* Owner);
vector <MyPanel*> ParaPanels;
};

class MyPanel : public TPanel
{
private:

public:
__fastcall MyPanel(TComponent* Owner);
vector <int> number;
vector <float> value;

__fastcall ~MyPanel();
};
__fastcall MyPanel::MyPanel(TComponent* Owner) : TPanel(Owner{}
__fastcall MyPanel::~MyPanel()
{
if(value.size() > 0)
{
number.clear();
value.clear();
ShowMessage("delete panel");
}
}
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif
////////////////////////////////////////////////////////////////////////////////
CPP文件:

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "test.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
for (int i = 0;i < 10;i++)
{
MyPanel* panel = new MyPanel(this) ;
panel->Parent = this;
panel->Width = 38; //
panel->BorderWidth = 0;
panel->Top = 100;
panel->Left = 10 + i * 40;
panel->Height = 20;

this->ParaPanels.push_back(panel);
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
for(int i = 0;i < this->ParaPanels.size();i++)
{
for (int j = 0;j < 1000;j++)
{
this->ParaPanels[i]->number.push_back(j + 1);
this->ParaPanels[i]->value.push_back(j * 1.2f);
}
}
}
//---------------------------------------------------------------------------

编译运行后，先按button1添加panels，然后按button2往vector里添加数据。当关闭程序时，提示：“Project Project1.exe raised exception class EAccessViolation with message 'Access violation at address 00000000.
Read of address 00000000'. Process stopped. Use Step or Run to continue.”请问为什么会出现这个错误。据我所知，错误的起源在于这段代码
“for (int j = 0;j < 1000;j++)
{
this->ParaPanels[i]->number.push_back(j + 1);
this->ParaPanels[i]->value.push_back(j * 1.2f);
}
”
请问为什么会出现这个错误？？？

[baihacker]

看上去这些都是正确初始化了的.你跟一下,到j循环前,看看
this->ParaPanels[i]
是不是NULL

[帅得不敢出门]

输出this->ParaPanels.size();看看

[帅得不敢出门]

for (int i = 0;i < 10;i++)
{
MyPanel* panel = new MyPanel(this) ;
panel->Parent = this;
panel->Width = 38; //
panel->BorderWidth = 0;
panel->Top = 100;
panel->Left = 10 + i * 40;
panel->Height = 20;

this->ParaPanels.push_back(panel);
}

内存释放清楚了没有

[boys2002]

不敢乱说



先帮顶下~~~~~~~~~~~~~~~~·



先关注一下

[珍惜生命远离CPP]

ShowMessage("delete panel"); 

改为

MessageBox(0,"delete panel",0,0);

[珍惜生命远离CPP]

ShowMessage里面用到了其他的全局变量,有可能是这个原因造成的.
所以会有访问内存的问题.

[aatny1]

找到原因了，是关闭程序时，没有手动delete MyPanel*.

[backway]

mark

[chenyi3315]

up。。。

[baihacker]

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