Question

所以我的程序在点击＆＃34; 1＆＃34;之后基本上要求分配名称/学生姓名。从学生菜单中提交作业。该函数从我在调试文件夹中的文本文件中读取任意分配，名为＆＃34; myassignment.txt＆＃34;。然后它创建一个名为＆＃34; submission.txt＆＃34;的新文件。带有作业名称，学生姓名和作业当我点击＆＃34; 2＆＃34;从学生菜单中查看提交的作业，它会打印作业名称和学生名称，但跳过实际作业第一行的前几个字符。
它会根据作业名称和学生姓名的长度跳过更多或更少的字符我无法弄清楚它为什么要这样做这是我在菜单的前两个选项中使用的数据结构，菜单和函数的代码：

#include "assignmentgrading3.h"

#define MAX_STUDENT_NAME_SIZE 50
#define MAX_ASSIGNMENT_NAME_SIZE 50
#define MAX_ASSIGNMENT_SIZE 1000

typedef struct{
    char assignmentName[MAX_ASSIGNMENT_NAME_SIZE];
    char studentName[MAX_STUDENT_NAME_SIZE];
    char assignment[MAX_ASSIGNMENT_SIZE];
    double score;
} Assignment;

    void studentMenu(Assignment* assignmentStruct) {
        int choice;
        do {
            printf("\nStudent Menu:\n");
            printf("1. Submit an assignment\n");
            printf("2. See the submitted assignment\n");
            printf("3. See the graded assignment\n");
            printf("4. Exit\n");
            printf("Please enter a number from 1 - 4: ");
            scanf("%d", &choice);

            switch (choice) {
                case 1:
                    submitAssignment(assignmentStruct, "myassignment.txt");
                    break;
                case 2:
                    getAssignment(assignmentStruct);
                    displayAssignment(assignmentStruct);
                    break;
                case 3:
                    getGradedAssignment(assignmentStruct);
                    displayGradedAssignment(assignmentStruct);
                    break;
                case 4:
                    exit(0);
                    break;
            }
        } while (choice != 5);
    }

void readRemainingLines(FILE* pFile, char* assignment){
    long charsRead = 0;
    while(fgets(assignment + charsRead, MAX_ASSIGNMENT_SIZE - charsRead, pFile)!= NULL)
    {
        charsRead = strlen(assignment);
        if(charsRead >= MAX_ASSIGNMENT_SIZE - 1)  //Credits: Carl Gelfand
        break;
    }
    assignment[MAX_ASSIGNMENT_SIZE-1] = 0;  //Just to make sure.
}

//Reads the file whose name is provided as string “fileName”, 
//and creates a file named  “submission.txt” as specified in the functional specification. 
//It returns a 1 when it is successful, otherwise it returns a 0. 
int submitAssignment(Assignment* assignmentStruct, char* fileName) {
    FILE* pFile =0;
    //char assignment[MAX_ASSIGNMENT_SIZE];
    char* submissionFileName="submission.txt";

    //Reading information from a user provided file : fileName
    pFile = fopen(fileName,"r");
    if(pFile==NULL){
        printf("%s file did not open\n,",fileName);
        exit(0);
    }//EO if(pFile==NULL)
    printf("Please enter the name of the assignment: ");
    scanf(" %s", assignmentStruct->assignmentName);

    printf("Please enter  your (student) name: ");
    scanf(" %s", assignmentStruct->studentName);
    readRemainingLines(pFile,  assignmentStruct->assignment);
    fclose(pFile);

    // Writing Information to "submission.txt"
    pFile = fopen(submissionFileName, "w");
    if(pFile == NULL) {
        printf("%s file did not open\n,", submissionFileName);
        exit(0);
    } //EO if(pFile==NULL)

    fprintf(pFile, "%s\n", assignmentStruct->assignmentName);
    fprintf(pFile, "%s\n", assignmentStruct->studentName);
    fprintf(pFile, "%s\n", assignmentStruct->assignment);
    fclose(pFile); 
    return 1;
}


int getAssignment(Assignment* assignmentStruct) {
    FILE* pFile = 0;
    pFile = fopen("submission.txt","r");
    if(pFile==NULL){
        printf("file did not open\n,");
        exit(0);
    }
    fscanf(pFile, "%[^\n]", assignmentStruct->assignmentName);
    fscanf(pFile, "%[^\n]", assignmentStruct->studentName);
    readRemainingLines(pFile, assignmentStruct->assignment);
    return 1;
}

void displayAssignment(Assignment* assignmentStruct) {
    char* middleOfAssignment = &(assignmentStruct->assignment[strlen(assignmentStruct->assignmentName) + strlen(assignmentStruct->studentName) + 2]);
    print(assignmentStruct->assignmentName, assignmentStruct->studentName);
    printf("%s \n", middleOfAssignment);
    //printf("%s \n", assignment);
}

void print(char* assignmentName, char* studentName) {
    printf("Assignment Name: %s \nStudent: %s\n", assignmentName, studentName);
}

Answer 1

displayAssignment在分配middleOfAssignment时会跳过作业的前几个字符。它正在跳过第一个strlen(assignmentStruct->assignmentName) + strlen(assignmentStruct->studentName) + 2字符。

它应该只打印assignmentStruct->assignment，不需要middleOfAssignment。该代码的唯一原因是，如果assignment在开头包含作业名称和学生姓名的副本，但它不会。

void displayAssignment(Assignment* assignmentStruct) {
    print(assignmentStruct->assignmentName, assignmentStruct->studentName);
    printf("%s \n", assignmentStruct->assignment);
}

程序不会从第一行文本文件中读取某些字符

1 个答案: