错误_BLOCK_TYPE_IS_VALID（pHead-＆gt; nBlockUse）

Question

我编写了一个从文件中读取Image（2-d数组）并返回它的函数。

调用它给了我一个Block-Type错误，我可以通过删除析构函数来抑制它 我的错误在哪里？我甚至需要一个析构函数吗？

#include <vector>
#include <stdio.h>
#include <conio.h>
#include <iostream>
#include <fstream>
using namespace std;

struct Pixel {
    float p;
};

class Image {
    int _x, _y;
    Pixel *pix;
public:
    Image(int x, int y) {
        pix = new Pixel[x * y];
        _x = x;
        _y = y;
    }
    ~Image() {
        delete[] pix;
        pix = NULL;
    }
    Image& operator= (const Image& param) {
        _x = param._x;
        _y = param._y;
        pix = new Pixel[_x*_y];
        pix = param.pix;
        return *this;
    }
    float getPixel(int i, int j) {
        return pix[(i-1) * _y + (j-1)].p;
    }
    void setPixel(int i,int j, Pixel val) {
        pix[(i-1) * _y + j-1].p = val.p;
    }
    Pixel **GetData() {
        Pixel **a=0;
        a = new Pixel*[_x];
        for (int i = 0; i < _x; i++) {
            a[i] = new Pixel[_y];
            for (int j = 0; j < _y; j++)
                a[i][j] = pix[i*_y + j];
        }
        return a;
    }
};

Image ReadFromFile(string a) {
    FILE * pFile;
    const char * c = a.c_str();
    Pixel pix,**tval;
    int n,m;
    pFile=fopen(c,"r");
    fscanf(pFile, "%i %i", &n, &m);
    Image img(n, m);
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++) {
            fscanf(pFile, "%f", &pix.p);
            img.setPixel(i, j, pix);
        }
    fclose(pFile);
    return img;
}

int main(){
    // Example Usage
    Image img(10, 10);
    Image img2(3, 3);
    Pixel val[10][10], **tval;
    for (int row = 1; row <= 10; row++)
        for (int col = 1; col <= 10; col++) {
            val[row-1][col-1].p = 2*row + col;
            img.setPixel(row, col, val[row-1][col-1]);
        }

    for (int row = 1; row <= 10; row++) {
        for (int col = 1; col <= 10; col++)
            cout << img.getPixel(row,col) << ' ';
        cout << '\n';
    }
    cout << '\n';
    tval = img.GetData();
    for (int row = 0; row < 10; row++) {
        for (int col = 0; col < 10; col++)
            cout << tval[row][col].p << ' ';
        cout << '\n';
    }
    string a;
    a = "C:/programs/misha/out.txt";
    img2 = ReadFromFile(a);
    cout << '\n';
    for (int row = 0; row < 3; row++) {
        for (int col = 0; col < 3; col++)
            cout << img2.getPixel(row+1, col+1) << ' ';
        cout << '\n';
    }
}