#include<stdio.h>
#include<malloc.h>
/*
* 二叉树的遍历
*/
typedef struct BTNode {
    char data;//数据域
    struct BTNode* lchild;//左孩子指针域
    struct BTNode* rchild;//右孩子指针域
}BTNODE, * PBTNODE;
PBTNODE    CreateBTree(void);//创建二叉树
void PreOrderTraverseBTree(PBTNODE pT);//二叉树先序遍历的递归算法
void InOrderTraverseBTree(PBTNODE pT);//中序
void PostOrderTraverseBTree(PBTNODE pT);//后序

int main(void) {
    PBTNODE pT = CreateBTree();//相当于 struct BTNode *pT=CreateBTree()
    //CreateBTree函数返回的是指向树根的指针
    printf("前序遍历 \n");
    PreOrderTraverseBTree(pT);
    printf("中序遍历 \n");
    InOrderTraverseBTree(pT);
    printf("后序遍历 \n");
    PostOrderTraverseBTree(pT);
}
PBTNODE    CreateBTree(void) {
    PBTNODE pA = (PBTNODE)malloc(sizeof(BTNODE));
    PBTNODE pB = (PBTNODE)malloc(sizeof(BTNODE));
    PBTNODE pC = (PBTNODE)malloc(sizeof(BTNODE));
    PBTNODE pD = (PBTNODE)malloc(sizeof(BTNODE));
    PBTNODE pE = (PBTNODE)malloc(sizeof(BTNODE));

    pA->data = 'A';
    pB->data = 'B';
    pC->data = 'C';
    pD->data = 'D';
    pE->data = 'E';

    pA->lchild = pB;
    pA->rchild = pD;

    pB->lchild = NULL;
    pB->rchild = pC;

    pC->lchild = pC->rchild = NULL;


    pD->lchild = pE;
    pD->rchild = NULL;

    return pA;

}

void PreOrderTraverseBTree(PBTNODE pT) {

    if (pT != NULL) {

        printf("%c\n", pT->data);

        if (pT->lchild != NULL) {
            PreOrderTraverseBTree(pT->lchild);
        }
        if (pT->rchild != NULL) {
            PreOrderTraverseBTree(pT->rchild);
        }


    }

}
void InOrderTraverseBTree(PBTNODE pT) {

    if (pT != NULL) {
        if (pT->lchild != NULL) {
            InOrderTraverseBTree(pT->lchild);
        }
        printf("%c\n", pT->data);


        if (pT->rchild != NULL) {
            InOrderTraverseBTree(pT->rchild);
        }


    }

}
void PostOrderTraverseBTree(PBTNODE pT) {

    if (pT != NULL) {
        if (pT->lchild != NULL) {
            PostOrderTraverseBTree(pT->lchild);
        }
        if (pT->rchild != NULL) {
            PostOrderTraverseBTree(pT->rchild);
        }
        printf("%c\n", pT->data);





    }

}

而菜鸟在线编译时正常的

完美运行，没发现问题。应该是vs抽风了

your code works well by using online parse //https://www.bccn.net/run/
so the 1st thing you should do is that to ensure the 2 version source code has been synchronized(online_version vs 2019_version)
using txt comparison tool can help checking the difference parts: beyond compare
or using online compare: https://www.
after that:
starting  vs2019 debug mode step by step，dont forget to set breakpoint and open callstack window
its a very good opportunity to learn how to debug a project, good luck!

another 2 articles maybe helpful to you:
https://blog.
https://blog.

在函数 CreateBTree 中加一句 pE->lchild = pE->rchild = NULL; 试试

这个方法行 可是大佬是为什么呢

感谢大哥们的倾囊相助