Question

我在网上搜索了如何返回一个矢量对象，但我找不到最简单的一个。首先，我不是C ++方面的专家，几周前我刚刚开始使用C ++。返回对象向量是不是可以吗？

我有类似的东西。

我把它推到了某处：

主文件：

int main()
{   
    XIniFile *f = new XIniFile();
    int result = 0;

    int v = 0;
    char *val;

    result = f->open("doc2.ini");

    if (INI_FILE_RES_OK == result) {
    }

    else
        printf("Error[%d]\n", result);
}

CPP文件：

XKey::XKey()
{
}

XKey::~XKey()
{
}

XSection::XSection()
{
}

XSection::~XSection()
{
}

XKey *XSection::addKey(const char *k, const char *val)
{
    XKey *nk = new XKey;
    nk->setName(k);
    nk->setValue(val);
    m_vkey.push_back(*nk);
    return nk;
}

void XSection::showKey()
{
    vector<XKey>::iterator ik;
    for (ik = m_vkey.begin(); ik != m_vkey.end(); ik++)
        printf("%s = %s\n", ik->getName(), ik->getValue());
}

XIniFile::XIniFile()
{
    m_modified = false;
}

int XIniFile::open(const char *fn)
{   
    XSection *cs;

    char *sn;
    char *kn;
    char *val;
    int i = 0;

    FILE *f;
    f = fopen(fn, "r");

    if (!f)
        return INI_FILE_ERROR;

    struct stat file_stat;
    stat(fn, &file_stat);
    int size = file_stat.st_size;

    m_name = strdup(fn);

    char *d = (char *)malloc(size * sizeof(char *) + 1);

    fread(d, size, 1, f);

    while (i < size) {
        while (d[i] != '[') i++;

        if (d[i] == '[') {
            i++;

            while (isspace(d[i])) i++;

            sn = &d[i];
            while (d[i] != ']')
                i++;
            d[i++] = 0;

            cs = addSection(sn);

            while (isspace(d[++i]));

            while(d[i] != '[') {

                while (isspace(d[i])) i++;

                kn = &d[i];
                while (d[i] != '=') i++;
                d[i-1] = 0;
                i++;

                while (isspace(d[i])) i++;

                if (d[i] == '[') {
                    i++;
                    val = &d[i];
                    while (isspace(d[i])) i++;
                    d[i-1] = 0;
                }

                else {
                    val = &d[i];
                    while (d[i] != '\n') i++;
                    d[i] = 0;
                }
                i++;

                cs->addKey(kn, val);

                while (isspace(d[i])) {
                    i++;
                    if (i >= size) break;
                }

                if (i >= size) break;
            }
        }
    }    
    free(d);

    vector<XSection>::iterator is;

    for (is = m_vsection.begin(); is != m_vsection.end(); is++) {
        printf("[%s]\n", is->getName());
        printf("is->getSize()[%d]\n", is->getSize());
    }

    fclose(f);
    return INI_FILE_RES_OK;
}

XIniFile::~XIniFile()
{
    delete m_name;   
}

XSection *XIniFile::addSection(const char *s)
{
    XSection *ns = new XSection;
    ns->setName(s);
    m_vsection.push_back(*ns);

    return ns;
}

void XIniFile::showSection()
{
    vector<XSection>::iterator is;
    for (is = m_vsection.begin(); is != m_vsection.end(); is++)
        printf("[%s]\n", is->getName());
    printf("End\n");
}

标题文件：

class XKey
{   
public:
    XKey();
    virtual ~XKey();

    void *setName(const char *k) {m_name = strdup(k);}
    void *setValue(const char *v) {m_value = strdup(v);}
    char *getName(){return m_name;}
    char *getValue(){return m_value;}

private:
    char *m_name;
    char *m_value;
};

class XSection
{   
public:
    XSection();
    virtual ~XSection();  

    void *setName(const char *n) {m_name = strdup(n);}
    char *getName() {return m_name;}
    XKey *addKey(const char *k, const char *v);
    vector<XKey> getKey() {return m_vkey;}
    int getSize() {return m_vkey.size();}
    void showKey();

private:    
    char *m_name;
    vector<XKey> m_vkey;
};

class XIniFile
{
public:
    XIniFile();
    virtual ~XIniFile();

    int open(const char *);
    int readString(const char *, const char *, char **);
    int readInt(const char *, const char *, int *);
    XSection *addSection(const char *);
    void showSection();

private:
    char *m_name;
    vector<XSection> m_vsection;
    bool m_modified;
};

此处的问题是，在CPP文件is->getSize()下，即使我在push_back m_vkey上使用了addKey，也无法增加{{1}}方法。

Answer 1

这是因为您修改的对象与您正在存储的对象不同。

看这里：

XSection *XIniFile::addSection(const char *s)
{
    XSection *ns = new XSection;   // Create a new XSection
    ns->setName(s);
    m_vsection.push_back(*ns);     // Store a copy of ns

    return ns;                     // Return the original ns
}

现在当您使用返回值执行某些操作时，m_vsection中的对象不受影响。

最快的解决方法是存储您在m_vsection中返回的指针，而类似于节对象。
尽管如果可能的话，您应该开始使用std::shared_ptr（更不用说std::string）了。

返回vector <object> </object>

1 个答案: