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我是一个相当新的程序员，所以请多多包涵。我正在使用 VC++ 2008。

我从我的程序中收到此错误：

z projection.exe 中 0x68bce2ba (msvcp90d.dll) 处未处理的异常：0xC0000005：访问冲突写入位置 0x00630067。

然后计算机将我带到这一页代码，它看起来相当混乱，而且我绝对不是写的。它指出这部分代码是有问题的代码（由“<-computer points to this line”标记）：

public:
_CRTIMP2_PURE static size_t __CLRCALL_OR_CDECL _Getcat(const facet ** = 0,
    const locale * = 0)
{   // get category value, or -1 if no corresponding C category
    return ((size_t)(-1));
}

_CRTIMP2_PURE void __CLR_OR_THIS_CALL _Incref()
{   // safely increment the reference count
    _BEGIN_LOCK(_LOCK_LOCALE)
        if (_Refs < (size_t)(-1))
            ++_Refs;      <-computer points to this line
    _END_LOCK()
}

_CRTIMP2_PURE facet *__CLR_OR_THIS_CALL _Decref()
{   // safely decrement the reference count, return this when dead
    _BEGIN_LOCK(_LOCK_LOCALE)
    if (0 < _Refs && _Refs < (size_t)(-1))
        --_Refs;
    return (_Refs == 0 ? this : 0);
    _END_LOCK()
}

我已将其缩小到我自己的程序中可能导致崩溃的代码行（以“index”开头的第 4 行代码，也是 stage = 1）：

stringstream index;
string fileName = "";
index.str("");//

index << setw( 3 ) << setfill( '0' ) << stage - 1;

fileName = "positive Z topography-" + index.str() + ".txt";

令我困惑的是，我从我编写的另一个程序中复制并粘贴了这段代码，该程序已经运行了数百次，从来没有遇到过任何麻烦。

编辑：这是整个代码。

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <iomanip>

using namespace std;

int main ()
{
    int dim = 100;
    int steps = 9;  //step 0 = 1, steps = actual steps + 1
    int spread = 5; //number of points averaged to get a slope, must be an odd number
    int halfSpread = (spread - 1)/2; //redefine for eazier use in program (better efficency)

    char * partMap = new char [dim * dim * dim]; // cad data

    // positive and negitive denote the x direction the check is moving in. Positive is  0 -> x, negitive is x -> 0.
    unsigned short int * positiveProjection = new unsigned short int [dim * dim]; //projection arrays
    unsigned short int * negitiveProjection = new unsigned short int [dim * dim];

    unsigned short int * negitiveThickness = new unsigned short int [dim * dim];

    double * negitiveXGradient = new double [dim * dim];
    double * negitiveYGradient = new double [dim * dim];

    stringstream index;
    string fileName;

    ifstream txtFile;
    txtFile.open("3D CAD Part.txt");
    txtFile.read(partMap, dim * dim * dim);
    txtFile.close();


    for (int stage = 1; stage < steps; stage++)
    {

        cout << "stage " << stage << endl;

        //z axis projections
        //projection order is along x then along y, during each step, along z in both directions

        int k = 0; // z axis loop variable

        for (int j = 0; j < dim; j++)
        {
            for (int i = 0; i < dim; i++)
            {
                k = 0;

                while ((k != dim) && partMap[dim * ((dim - 1 - k) + dim * i) + j] < stage) 
                    k++;
                positiveProjection[dim * k + j] = k;

                k = dim;

                while ((k != 0) && partMap[dim * ((dim - 1 - (k - 1)) + dim * i) + j] < stage) 
                    k--;
                negitiveProjection[dim * k + j] = i;

                while ((k != 0) && partMap[dim * ((dim - 1 - (k - 1)) + dim * i) + j] >= stage) 
                    k--;
                negitiveThickness[dim * k + j] = negitiveProjection[dim * k + j] - k;
            }
        }

        // negitive dz/dx gradient
        for (int j = 0; j < dim; j++)
        {

            //first loop to handle the first edge gradients
            for (int i = 0; i < halfSpread; i++)
                negitiveXGradient[(j * dim) + i] = (double(negitiveProjection[(j * dim) + halfSpread + i]) - double(negitiveProjection[j * dim]))/(halfSpread + i); // untested

            //second loop to handle the main middle section
            for (int i = halfSpread; i < dim - halfSpread; i++)
                negitiveXGradient[(j * dim) + i] = (double(negitiveProjection[(j * dim) + i + halfSpread]) - double(negitiveProjection[(j * dim) + i - halfSpread]))/ (spread - 1); // untested

            //third loop to handle the end edge gradients
            for (int i = dim - halfSpread; i < dim; i++)
                negitiveXGradient[(j * dim) + i] = (double(negitiveProjection[(j * dim) + dim - 1]) - double(negitiveProjection[j * dim + i - halfSpread]))/((dim - 1) - i + halfSpread); // untested
        }

        // negitive dz/dy gradient
        for (int i = 0; i < dim; i++)
        {
            //first loop to handle the first edge gradients
            for (int j = 0; j < halfSpread; j++)
                negitiveYGradient[(j * dim) + i] = (double(negitiveProjection[((j + halfSpread) * dim) + i]) - double(negitiveProjection[i]))/(halfSpread + j); // untested

            //second loop to handle the main middle section
            for (int j = halfSpread; j < dim - halfSpread; j++)
                negitiveYGradient[(j * dim) + i] = (double(negitiveProjection[((j + halfSpread) * dim) + i]) - double(negitiveProjection[((j - halfSpread) * dim) + i]))/ (spread - 1); // untested

            //third loop to handle the end edge gradients
            for (int j = dim - halfSpread; j < dim; j++)
                negitiveYGradient[(j * dim) + i] = (double(negitiveProjection[(dim * (dim - 1)) + i]) - double(negitiveProjection[((j - halfSpread) * dim) + i]))/((dim - 1) - j + halfSpread); // untested
        }

        fileName = ""; // reset string and stringstream
        index.str("");//

        index << setw( 3 ) << setfill( '0' ) << stage - 1; // set index, index is -1 of stage due to the program structure

        fileName = "positive Z topography-" + index.str() + ".txt";

        ofstream outputFile1(fileName.c_str(), std::ios::binary | std::ios::out);
        outputFile1.write(reinterpret_cast<const char*>(positiveProjection), streamsize(dim * dim * sizeof(unsigned short int)));
        outputFile1.close();

        fileName = "negitive Z topography-" + index.str() + ".txt";

        ofstream outputFile2(fileName.c_str(), std::ios::binary | std::ios::out);
        outputFile2.write(reinterpret_cast<const char*>(negitiveProjection), streamsize(dim * dim * sizeof(unsigned short int)));
        outputFile2.close();

        fileName = "negitive Z thickness-" + index.str() + ".txt";

        ofstream outputFile4(fileName.c_str(), std::ios::binary | std::ios::out);
        outputFile4.write(reinterpret_cast<const char*>(negitiveThickness), streamsize(dim * dim * sizeof(unsigned short int)));    
        outputFile4.close();

        fileName = "negitive Z X gradient-" + index.str() + ".txt";

        ofstream outputFile5(fileName.c_str(), std::ios::binary | std::ios::out);
        outputFile5.write(reinterpret_cast<const char*>(negitiveXGradient), streamsize(dim * dim * sizeof(double)));
        outputFile5.close();

        fileName = "negitive Z Y gradient-" + index.str() + ".txt";

        ofstream outputFile6(fileName.c_str(), std::ios::binary | std::ios::out);
        outputFile6.write(reinterpret_cast<const char*>(negitiveYGradient), streamsize(dim * dim * sizeof(double)));
        outputFile6.close();
    }
}

好的，在我开始将结果输出到硬盘的最后一段代码之前，一切都很好。我使用了 VC++ 中的断点，并且在错误之前成功通过的最后一个断点位于前面提到的点（我发布的第二个代码块）。显然 HTML 也不喜欢我的 c++ 代码。

哦，还有，省去遍历循环的麻烦......它们应该没问题......那里有十几个循环，你不必担心它们发生了什么，它们非常安全。我只有最后一块有问题。

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2 回答 2

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即使最后一个块出现问题并不一定意味着循环中没有错误。如果您在任何阵列上超出范围，您可能直到稍后才会得到任何有关它的指示。

在第一个内部while循环中，您有

while ((k != dim) && partMap[dim * ((dim - 1 - k) + dim * i) + j] < stage) 
    k++;

这意味着在完成循环后k可能具有价值。然后下一行dimwhile

positiveProjection[dim * k + j] = k;

由于您尝试使用索引并且它只有维度，因此这将超出positiveProjection任何范围。jdim*dim + jdim*dim

于 2009-07-16T20:46:11.237 回答
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我是一个相当新的程序员，所以请多多包涵。

行。我保证不会取笑你；）

然后计算机将我带到此代码页面

您可能的意思是 Visual Studio 调试器将您带到这一行。您可以使用“堆栈跟踪”功能找到出错的确切位置：单击菜单调试 -> Windows -> 调用堆栈。

但是，我在您的代码中找不到任何错误。这个简单的应用程序完美运行：

int main()
{

    std::stringstream index;
    std::string fileName = "";
    index.str("");//
    int stage = 1;
    index << std::setw( 3 ) << std::setfill( '0' ) << stage - 1; 
    fileName = "positive Z topography-" + index.str() + ".txt";
    std::cout << "Done with test.\n";
    return 0;
}

因此，为了帮助您，我们需要查看更多您的代码...

于 2009-07-16T19:20:19.693 回答