Question

Visual Studio向我显示如下警告：
警告C4133：'='：不兼容的类型 - 从'FILE *'到'char *'
警告C4133：'function'：不兼容的类型 - 从'char *'到'FILE *'

警告在注释“此行”的行上。我该如何解决？

我的代码：

typedef struct {
int numberOfCity;
tListOfCity* list;
double** distances;
} tDatabase;

tDatabase* LoadDatabase(char* file) {
FILE* file;
tDatabase *input;
char data[100];
int i, j, number = 0;

input = (tDatabase*) calloc(1, sizeof (tDatabase));
input->list = NULL;

file = fopen("file.txt", "r");   //this line
fscanf(file, "%d", &number);     //this line
input->numberOfCity = number;

input->distances = (double**) calloc(data->numberOfCity, sizeof (double*));
for (i = 0; i < input->numberOfCity; i++) {
    input->distances[i] = (double*) calloc(input->numberOfCity, sizeof (double));
}

for (i = 0; i <= input->numberOfCity; i++) {
    fgets(data, sizeof (data), file);    //this line
    input->list = AddOnEnd(input->list, CreateCity(data));
}

for (i = 0; i < input->numberOfCity; i++) {
    for (j = 0; j < input->numberOfCity; j++) {
        fscanf(file, "%f", &input->distances[i][j]);   //this line
    }

fclose(file);
return input;

}

Answer 1

代码中有两个file个变量。首先是作为参数传入的内容，另一个是FILE * file。将参数更改为fileName或类似的内容，并修补代码以反映该参数。

tDatabase* LoadDatabase(char* fileName) {
FILE* file;
tDatabase *input;
char data[100];
int i, j, number = 0;

input = (tDatabase*) calloc(1, sizeof (tDatabase));
input->list = NULL;

file = fopen("file.txt", "r");   //this line
fscanf(file, "%d", &number);     //this line
input->numberOfCity = number;

input->distances = (double**) calloc(data->numberOfCity, sizeof (double*));
for (i = 0; i < input->numberOfCity; i++) {
    input->distances[i] = (double*) calloc(input->numberOfCity, sizeof (double));
}

for (i = 0; i <= input->numberOfCity; i++) {
    fgets(data, sizeof (data), file);    //this line
    input->list = AddOnEnd(input->list, CreateCity(data));
}

for (i = 0; i < input->numberOfCity; i++) {
    for (j = 0; j < input->numberOfCity; j++) {
        fscanf(file, "%f", &input->distances[i][j]);   //this line
    }

fclose(file);
return input;
}

Answer 2

您不应该为参数和局部变量指定相同的名称：

tDatabase* LoadDatabase(char* file) {
FILE* file;

也许这是一个很好的机会让你的函数尊重它作为参数获得的文件名（现在它总是打开“file.txt”）。

警告C4133，不兼容的类型

2 个答案: