qmap-example.cpp

来自「压缩包里有教材<<C++模式设计-基于QT4开源跨平台开发框架&gt」· C++ 代码 · 共 51 行

#include "textbook.h"
#include <QMap>
#include <qstd.h>
using namespace qstd;

//start id=impl
TextbookMap::~TextbookMap() {
    cout << "Destroying TextbookMap ..." << endl;
    foreach (QString key, keys())    /* keys() is a QMap function. */
        delete value(key);    /* Get and delete a pointer from the map. */
     clear(); 
}

void TextbookMap::add(Textbook* text) {
    insert(text->getIsbn(), text);
}

void TextbookMap::showAll() const {
    foreach (QString key, keys()) {
        Textbook* tb = value(key);  
        cout << '[' << key << ']' << ":" 
             << tb->toString() << endl;
    }
}

//end
//start id=client
int main() {
    Textbook* t1 = new Textbook("The C++ Programming Language",
        "Stroustrup", "0201700735", 1997);
    Textbook* t2 = new Textbook("XML in a Nutshell", 
        "Harold","0596002920", 2002);
    Textbook* t3 = new Textbook("UML Distilled", 
        "Fowler", "0321193687", 2004);
    Textbook* t4 = new Textbook("Design Patterns", "Gamma",
        "0201633612",1995);
    { /* Inner block for demonstration purposes */
        TextbookMap m;
        m.add(t1);
        m.add(t2);
        m.add(t3);
        m.add(t4);
        m.showAll();
        m.remove (t3->getIsbn());  /* Removed but not deleted */
    }  /* End of block - local variables destroyed. */
    cout << "After m has been destroyed we still have: \n" 
            << t3->toString() << endl;
    return 0;
}
//end