LNK2019：未解析的外部符號...在函數_main中引用

Question

我正在上一門入門編程課，所以我希望這個問題不是太可怕。 到目前為止，我已經修復了我的Main函數中的所有問題，但后來我取消注釋了我的Blob函數調用，並且出現了一個錯誤，我顯然無法搞清楚。 我已經研究過它，並沒有找到任何適合我的問題的東西。

我相信它與我用來修復我的2D數組的先前問題（這是分配所需的）的**有關。 我已將評論列在代碼頂部，以闡明該計划的目標。

錯誤是：

錯誤LNK2019：未解析的外部符號“void __cdecl Blob（char * *，int，int）”（？Blob @@ YAXPAPADHH @ Z）在函數_main c：\\ Users \\ Laura \\ documents \\ visual studio 2010 \\ Projects \\ pr9_lt12e \\中引用pr9_lt12e \\ p9_lt12e.obj

此外，輸出的數組的第一行向左偏移10個空格。 第13列應該有一個'X'，但是它顯示為3.我已經手動更改了數組的值，以便arr [0] [12] ='X'（在數組打印出來之前）但位置確實如此沒變。 我仍然可以在沒有修復的情況下使用該程序，因為它只有幾個點。

我的整個代碼是：

/*
         SUMMARY 
           This program will read in data from a file and store it in a two-dimensional array. 
           From there it will detect all of the groupings of characters, or "blobs", in the file and count them.

         INPUT 
           The program will read in information from a file called "blob.txt".

           BAD DATA CHECKING: 
                N/A

         OUTPUT 
            The program will output the amount of blobs in the file.

         DATA STRUCTURES
            N/A

         ASSUMPTIONS  
          -The file will have 20 records. Each record will be 70 characters long and the character 
            will be either an X or a blank space/whitespace.

*/

#include <iostream>
#include <iomanip>
#include <cmath>    
#include <fstream>
#include <string>
using namespace std;

//GLOBAL CONSTANTS
const int   ONE_D = 22,
            TWO_D = 72,
            SEVEN = 7;

const char  X = 'X',
            B = ' ';

//FUNCTION PROTOTYPES
void Blob(char**, int, int);    //Retrieves data from the file and places it into the array


//MAIN FUNCTION
int main()
{
    //Declare variables
    ifstream file;

    string line;

//  char character;

    int index1 = 0,
        index2 = 0,
        col1 = 0,
        col2 = 0,
        blobCount = 0;

    //Declare the 2D array. From course website.
    char ** arr;
    arr = new char * [ONE_D];
    for (index1 = 0; index1 < ONE_D; index1++)
        arr[index1] = new char [TWO_D];

    //Welcome message
    cout << "Welcome to the Recursive Blob Finder program!\n\n";

    //Open the file
    file.open("blob.txt");

    //Check to see if file has been opened
    if (file.is_open())
        cout << "The file has been opened!\n\n";
    else
        cout << "The file has not been opened!\n\n";

    //Read in data from the file and write to the array
    for (index1 = 0; index1 < 20; index1++) {
        getline(file, line);
        strcpy_s(arr[index1], 72, line.c_str()); 
    }

    ////Row 1 is offset by -10. Adjust first row.
    //arr[0][2] = B;
    //arr[0][12] = X;

    //Clear non-'X' cells
        for (index1 = 0; index1 < 22; index1++) {
            for (index2 = 0; index2 < 72; index2++) {
                if (arr[index1][index2] != X)
                    arr[index1][index2] = B;
            }
        }

    //Print numbered lines
    for (col1 = 1; col1 < 8; col1++)    
        cout << "         " << col1;

    cout << endl;

    for (col2 = 1; col2 < 8; col2++)    
        cout << "1234567890";

    cout << endl;    //EDIT IS HERE

    //Print array
    for (index2 = 0; index2 < 20; index2++) {

        for (index1 = 0; index1< 70; index1++)
            cout << arr[index2][index1];

        cout << endl;
    }

    //Search array for 'X' characters
    for (index1 = 0; index1 < 20; index1++)     {

        for (index2 = 0; index2 < 70; index2++) {

            //When X is found, add 1 to blob count. Blob function will clear out the remaining blob characters
            if (arr[index1][index2] == X)   {
                blobCount++;
                Blob(arr, index1, index2);
            }
        }
    }

    //Close the file
    file.close();

    return 0;

}


//OTHER FUNCTIONS   

//Name: Blob
//Description:  Recursive function to find and clear each blob.
void Blob(char **c[ONE_D][TWO_D], int row, int col)  
{
        //Eliminate one blob at a time

    //Potential positions for 'X' after clearing the last X:         Ox
    //                                                              xxx


    if (**c[row][col]==X)   {
        **c[row][col] = B;

        //Test for X's connected to current blob
        if (**c[row][col+1]==X)
            Blob (c, row, col);

        if (**c[row+1][col-1]==X)
            Blob (c, row, col);

        if (**c[row+1][col] == X)
            Blob (c, row, col);

        if (**c[row+1][col+1]==X)
            Blob (c, row, col);
    }   
}

我嘗試過的一些事情包括改變原型：

void Blob(char** c[ONE_D][TWO_D], int, int);

功能調用：

Blob(arr[][], index1, index2);
Blob(arr[][72], index1, index2);
Blob(arr[22][72], index1, index2);

和函數定義參數：

void Blob(char c[ONE_D][TWO_D], int row, int col)

Answer 1

問題是你聲明了一個名為blob(char **, int, int)的函數，然后將該聲明更改為blob(char **c[ONE_D][TWO_D], int, int) 。

鑒於你確實將char **arr傳遞給函數，我建議你刪除[ONE_D][TWO_D]部分，因為這實際上是使你的函數采用4維數組[或指向指針的指針一個二維數組，可能]。

您還需要將**c[...][...]更改為c[...][...] 。