Question

我试图为我的项目做一个密码，我发现了getline的一个错误，因为我希望用＃39;来填充字符串。＆＃39;但是当我输入“＆＃39;。＆＃39;错误显示＆＃34; Mini-Project.exe中的0x77031D4D处的未处理异常：Microsoft C ++异常：内存位置0x00C6F478处的std :: out_of_range。＆＃34;我已经试图修复这个错误数周，但我不能。请告诉我我的错误。我很乐意学习新的代码方法。感谢。

#include <iostream>
#include <string>

using namespace std;

class Encryption 
{
private:
string encrypt;
string decrypt;

public:
Encryption();
Encryption(string,string);
void set_encryption(string&);
string encryption();
void set_decryption(string);
string decryption();
};

Encryption::Encryption()
{
 encrypt = "";
 decrypt = "";
}

Encryption::Encryption(string Encrypt,string Decrypt)
{
 encrypt = Encrypt;
 decrypt = Decrypt;
}

void Encryption::set_encryption(string &Encrypt)
{
 encrypt = Encrypt;
}

string Encryption::encryption()
{
 char a;
 string text1(encrypt);
 for (int i = 0; i <= encrypt.size() - 1; i++)
{
    a = encrypt.at(i);
    int b = (int)a;
    b += 1;

    //if (b > 254) { b = 254; }
    a = (char)b;
    text1.insert(i, 1, a);
}
 string Encrypted(text1, 0, encrypt.size());
 encrypt = Encrypted;
 return encrypt;
}

void Encryption::set_decryption(string Decrypt)
{

 decrypt = Decrypt;
}

string Encryption::decryption()
{
 char c;
 string text2(decrypt);

 for (int i = 0; i <= (decrypt.size() - 1); i++)
{
    c = decrypt.at(i);
    int d = (int)c;
    d -= 1;
    c = (char)d;
    text2.insert(i, 1, c);
}
 string Decrypted(text2, 0, decrypt.size());
 decrypt = Decrypted;
 return decrypt;
}

int main()
{
 while (1)
{
    //initialize and get the string from the user
    Encryption text;
    char a,ans,text1c;
    string text1, text2;
    do
    {
        cout << "****Welcome to Subition Cpiher****" << endl;
        cout << "This Program Only Allow Alphabet." << endl;
        cout << "Please Enter \n1-Encrypt \n2-Decrypt\n3-Clear Screen \n0-End " <<        "\n:";
        cin >> a;
    }
    while (a != '1' && a != '2' && a != '0' && a!='3');
    if (a == '1')
    {
        again:char c;
        cout << "Enter a string to encrypt <End with '.'>: ";
        getline(cin, text1, '.');

        c = text1.at(1);
        if (c == '.')
        {
            cout << "You have not enter any string. Please try again." << endl;
            goto again;
        }
        else
        {
            text1.erase(text1.begin());
            text.set_encryption(text1);
            cout << "The encrypted text is: " << text.encryption() << endl; 

        }
    }
    else if (a == '2')
    {
        cout << "Enter a string to decrypt <End with '.'>: ";
        getline(cin, text2, '.');
        text2.erase(text2.begin());
        text.set_decryption(text2);
        cout << "The decryted text is: " << text.decryption() << endl;
    }
    else if (a == '0')
    {
        cout << "Thank you for using the software." << endl;
        system("pause");
        return 0;
    }
    else if (a == '3')
    {
        system("cls");
    }
}
}

Answer 1

替换

c = text1.at（1）; if（c ==＆＃39;。＆＃39;）

与

if（text1.size（）== 1）

当你把。你有一个带有空字符串的1个元素的数组，并尝试做text1.at（1）这个读取一个不存在的内存块所以不要这样做。

玩得开心

Mini-Project.exe中0x77031D4D处的未处理异常：Microsoft C ++异常：内存位置为0x00CFF620的std :: out_of_range

1 个答案: