c - 在动态分配的结构中初始化动态分配的结构

Question

我想在结构中动态分配结构。我想我可以做到这一点。但是，当我想对它们执行操作时，我在 Visual C++ 下遇到访问冲突错误。也许初始化有问题。顺便问一下，如何初始化动态分配的 myDynamicMembersBinArray？我尝试了以下方法:

#include <stdio.h>
#include <stdlib.h>



int main()
{
    /* ========== Define structures ========== */

    /* Create just the identifier */
    struct bin{
        char *tag;
        float size;
    };
    /* Declare another structure which will hold the bin structure */
    struct dynamicbin{
    struct bin *binPointer;
    };
    /* I use calloc so that zero-filling is done */
    myDynamicMembersBinArray = (struct dynamicbin*)calloc(1, sizeof(struct dynamicbin));
    struct bin *binpointer = (struct bin*)calloc(N, sizeof(struct bin));

    /* This one fails */
    for (int i=0; i<N; i++){
        printf("%f\n", (*(*myDynamicMembersBinArray).binPointer+i).size);
    }

提前谢谢你。

Answer 1

你没有声明myDynamicMembersBinArray:
struct dynamicbin* myDynamicMembersBinArray = calloc(1, sizeof(struct dynamicbin));

struct bin *binpointer = (struct bin*)calloc(N, sizeof(struct bin)); 应该是
(*myDynamicMembersBinArray).binPointer = calloc(N, sizeof(struct bin));
(*myDynamicMembersBinArray 周围的括号很重要)或更好
myDynamicMembersBinArray->binPointer = calloc(N, sizeof(struct bin));

最后但并非最不重要的
printf("%f\n", (*(*myDynamicMembersBinArray).binPointer+i).size); 应该是
printf("%f\n", *((*myDynamicMembersBinArray).binPointer+i).size);
(注意 * 移到括号外)或更好
printf("%f\n", myDynamicMembersBinArray->binPointer[i].size);