如何將一個字符指針數組作為void *傳遞，然后轉換回字符指針數組？

Question

我將一個字符指針數組傳遞給sqlite3_exec ，它接受1個參數並將其顯示為void * ，但后來我想將它作為回調函數中的字符指針數組來訪問。

char *output_params[] = {"one", "two"};
result = sqlite3_exec(db, sql_statement, callback, output_params, &zErrMsg);

....

static int callback(void *param, int argc, char **argv, char **azColName) {
    // How do I access my character array?
    char *output_params[2] = (char **)param;
}

我通過后如何訪問它？

Answer 1

這對我有用：

int callback(void *param, int argc, char **argv, char **azColName)
{
    const char** p = (const char **)param;
    printf("%s\n", p[0]);
    printf("%s\n", p[1]);
}

這是演示概念的簡單程序。

#include <stdio.h>

void foo(void* in)
{
    char **p = (char**)in;
    printf("%s\n", p[0]);
    printf("%s\n", p[1]);
}

void main(int argc, char** argv)
{
   char *output_params[] = {"one", "two"};
   foo(output_params);
}