C++ Qt开发之关联容器类使用方法详解

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QtGlobal>
#include <QMap>
#include <QMapIterator>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QMap<QString,QString> map;

    map["1001"] = "admin";
    map["1002"] = "guest";
    map.insert("1003","lyshark");
    map.insert("1004","lucy");
    // map.remove("1002");

    // 根据键值对查询属性
    std::cout << map["1002"].toStdString().data() << std::endl;
    std::cout << map.value("1003").toStdString().data() << std::endl;
    std::cout << map.key("admin").toStdString().data() << std::endl;

    // 使用STL语法迭代枚举Map键值对
    QMap<QString,QString>::const_iterator x;
    for(x=map.constBegin();x != map.constEnd(); ++x)
    {
        std::cout << x.key().toStdString().data() << " : ";
        std::cout << x.value().toStdString().data() << std::endl;
    }

    // 使用STL语法实现修改键值对
    QMap<QString,QString>::iterator write_x;
    write_x = map.find("1003");
    if(write_x !=map.end())
        write_x.value()= "you ary in";

    // 使用QTglobal中自带的foreach遍历键值对
    QString each;

    // --> 单循环遍历
    foreach(const QString &each,map.keys())
    {
        std::cout << map.value(each).toStdString().data() << std::endl;
    }

    // --> 多循环遍历
    foreach(const QString &each,map.uniqueKeys())
    {
        foreach(QString x,map.value(each))
        {
            std::cout << each.toStdString().data() << " : ";
            std::cout << x.toStdString().data() << std::endl;
        }
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QList>
#include <QMultiMap>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QMultiMap<QString,QString> mapA,mapB,mapC,mapD;

    mapA.insert("lyshark","1000");
    mapA.insert("lyshark","2000");
    mapB.insert("admin","3000");
    mapB.insert("admin","4000");
    mapC.insert("admin","5000");

    // 获取到里面的所有key=lyshark的值
    QList<QString> ref;

    ref = mapA.values("lyshark");
    for(int x=0;x<ref.size();++x)
    {
        std::cout << ref.at(x).toStdString().data() << std::endl;
    }

    // 两个key相同可相加后输出
    mapD = mapB + mapC;

    ref = mapD.values("admin");
    for(int x=0;x<ref.size();x++)
    {
        std::cout << ref.at(x).toStdString().data() << std::endl;
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QHash>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QHash<QString, QString> hash;

    hash["1001"] = "admin";
    hash["1002"] = "guest";
    hash.insert("1003", "lyshark");
    hash.insert("1004", "lucy");
    // hash.remove("1002");

    // 根据键值对查询属性
    std::cout << hash["1002"].toStdString().data() << std::endl;
    std::cout << hash.value("1003").toStdString().data() << std::endl;
    std::cout << hash.key("admin").toStdString().data() << std::endl;

    // 使用STL语法迭代枚举Hash键值对
    QHash<QString, QString>::const_iterator x;
    for (x = hash.constBegin(); x != hash.constEnd(); ++x)
    {
        std::cout << x.key().toStdString().data() << " : ";
        std::cout << x.value().toStdString().data() << std::endl;
    }

    // 使用STL语法实现修改键值对
    QHash<QString, QString>::iterator write_x;
    write_x = hash.find("1003");
    if (write_x != hash.end())
        write_x.value() = "you are in";

    // 使用Qt中自带的foreach遍历键值对
    QString each;

    // --> 单循环遍历
    foreach (const QString &each, hash.keys())
    {
        std::cout << hash.value(each).toStdString().data() << std::endl;
    }

    // --> 多循环遍历
    foreach (const QString &each, hash.uniqueKeys())
    {
        foreach (QString x, hash.values(each))
        {
            std::cout << each.toStdString().data() << " : ";
            std::cout << x.toStdString().data() << std::endl;
        }
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QSet>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QSet<QString> set;

    set << "dog" << "cat" << "tiger";

    // 测试某值是否包含于集合
    if(set.contains("cat"))
    {
        std::cout << "include" << std::endl;
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QtGlobal>
#include <QList>
#include <QMap>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QMap<QString,QList<float>> map;
    QList<float> ptr;

    // 指定第一组数据
    ptr.append(10.1);
    ptr.append(12.5);
    ptr.append(22.3);
    map["10:10"] = ptr;

    // 指定第二组数据
    ptr.clear();
    ptr.append(102.2);
    ptr.append(203.2);
    ptr.append(102.1);
    map["11:20"] = ptr;

    // 输出所有的数据
    QList<float> tmp;
    foreach(QString each,map.uniqueKeys())
    {
        tmp = map.value(each);
        std::cout << "Time: " << each.toStdString().data() << std::endl;
        for(qint32 x=0;x<tmp.count();x++)
        {
            std::cout << tmp[x]<< std::endl;
        }
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QtGlobal>
#include <QList>
#include <QMap>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QList<QString> Header = {"MemTotal","MemFree","Cached","SwapTotal","SwapFree"};
    QList<float> Values = {12.5,46.8,68,100.3,55.9};
    QMap<QString,float> map;

    // 将列表合并为一个字典
    for(int x=0;x<Header.count();x++)
    {
        QString head = Header[x].toStdString().data();
        float val = Values[x];
        map[head] = val;
    }

    // 输出特定字典中的数据
    std::cout << map.key(100.3).toStdString().data() << std::endl;
    std::cout << map.value("SwapTotal") << std::endl;

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QtGlobal>
#include <QList>
#include <QMap>

void Display(QMap<QString,float> map)
{
    foreach(const QString &each,map.uniqueKeys())
    {
        std::cout << each.toStdString().data() << std::endl;
        std::cout << map.value(each) << std::endl;
    }
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QMap<QString,float> map;

    map["MemTotal"] = 12.5;
    map["MemFree"] = 32.1;
    map["Cached"] = 19.2;

    Display(map);

    QList<QString> map_key;
    QList<float> map_value;

    // 分别存储起来
    map_key = map.keys();
    map_value = map.values();

    // 输出所有的key值
    for(int x=0;x<map_key.count();x++)
    {
        std::cout << map_key[x].toStdString().data() << std::endl;
    }

    // 输出所有的value值
    for(int x=0;x<map_value.count();x++)
    {
        std::cout << map_value[x] << std::endl;
    }

    return a.exec();
}

#include <QCoreApplication>
#include <iostream>
#include <QString>
#include <QtGlobal>
#include <QList>

struct MyStruct
{
    int uuid;
    QString uname;
};

void Display(QList<int> ptr)
{
    foreach(const int &each,ptr)
        std::cout << each << " ";
    std::cout << std::endl;
}

// 由大到小排列
int compare(const int &infoA,const int &infoB)
{
    return infoA > infoB;
}

// 针对结构体的排序方法
void devListSort(QList<MyStruct> *list)
{
    std::sort(list->begin(),list->end(),[](const MyStruct &infoA,const MyStruct &infoB)
    {
        return infoA.uuid < infoB.uuid;
    });
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    // 定义并对单一数组排序
    QList<int> list = {56,88,34,61,79,82,34,67,88,1};
    std::sort(list.begin(),list.end(),compare);
    Display(list);

    // 定义并对结构体排序
    QList<MyStruct> list_struct;
    MyStruct ptr;

    ptr.uuid=1005;
    ptr.uname="admin";
    list_struct.append(ptr);

    ptr.uuid=1002;
    ptr.uname = "guest";
    list_struct.append(ptr);

    ptr.uuid = 1000;
    ptr.uname = "lyshark";
    list_struct.append(ptr);

    devListSort(&list_struct);

    for(int x=0;x< list_struct.count();x++)
    {
        std::cout << list_struct[x].uuid << " ---> ";
        std::cout << list_struct[x].uname.toStdString().data() << std::endl;
    }

    return a.exec();
}