QT的MVC模式的解析与实践

1. QT的model/View架构

数据源直接与Model交互；

Model与View之间通过Deleget来交互

2. 一个model可以对应多个视图

3. 工程实践

目标做一个表格显示，

Model：用一个QAbstractTableModel的派生类

View： QTableView

具体实现如下：

1) 工程文件与目录结构

除了工程文件，包含三个文件，一个是主程序main.c. 另外两个用于实现派生模型类modelex.h,modelex.cpp

2)ModelEx.pro内容

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = ModelEx

TEMPLATE = app

SOURCES += main.cpp

#        mainwindow.cpp 

    modelex.cpp

HEADERS  +=     modelex.h

#        mainwindow.h 

3)main.cpp内容

//#include "mainwindow.h"

#include 

#include "modelex.h"

#include 

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    ModelEx modelEx;

    QTableView view;

    view.setModel(&modelEx);

    //view.setWindowTitle(QObject::tr("modelEx"));

    view.setWindowTitle(QString::fromLocal8Bit("扩展模型演示"));

    view.resize(400,400);

    view.show();

    return a.exec();

}

4）modelex.h

#ifndef MODELEX_H

#define MODELEX_H

#include 

#include 

#include 

#include 

class ModelEx : public QAbstractTableModel

{

    Q_OBJECT

public:

    explicit ModelEx(QObject *parent = 0);

    virtual int rowCount(const QModelIndex &parent=QModelIndex()) const;

    virtual int columnCount(const QModelIndex &parent=QModelIndex()) const;

    QVariant data(const QModelIndex &index, int role) const;

    QVariant headerData(int section, Qt::Orientation orientation, int role) const;

signals:

public slots:

private:

    QVector army;

    QVector weaponType;

    QMap armyMap;

    QMap weaponTypeMap;

    QStringList  weapon;

    QStringList  header;

    void populateModel();

};

#endif // MODELEX_H

5) modelex.cpp

#include "modelex.h"

ModelEx::ModelEx(QObject *parent) :

    QAbstractTableModel(parent)

{

    armyMap[1]= QString::fromLocal8Bit("空军");

    armyMap[2]=QString::fromLocal8Bit("海军");

    armyMap[3]=QString::fromLocal8Bit("陆军");

    armyMap[4]=QString::fromLocal8Bit("海军陆战队");

    weaponTypeMap[1]=QString::fromLocal8Bit("轰炸机");

    weaponTypeMap[2]=QString::fromLocal8Bit("战斗机");

    weaponTypeMap[3]=QString::fromLocal8Bit("航空母舰");

    weaponTypeMap[4]=QString::fromLocal8Bit("驱逐舰");

    weaponTypeMap[5]=QString::fromLocal8Bit("直升机");

    weaponTypeMap[6]=QString::fromLocal8Bit("坦克");

    weaponTypeMap[7]=QString::fromLocal8Bit("两栖攻击舰");

    weaponTypeMap[8]=QString::fromLocal8Bit("两栖战车");

    populateModel();

}

void ModelEx::populateModel()

{

    header< 
    army<<1<<2<<3<<4<<2<<4<<3<<1;
 
    weaponType<<1<<3<<5<<7<<4<<8<<6<<2;
 
    weapon< 
}
 
 
int ModelEx::columnCount(const QModelIndex &parent) const
 
{
 
    return 3;
 
}
 
 
int ModelEx::rowCount(const QModelIndex &parent) const
 
{
 
    return army.size();
 
}
 
 
QVariant ModelEx::data(const QModelIndex &index, int role) const
 
{
 
    if(!index.isValid())
 
        return QVariant();
 
 
    if(role==Qt::DisplayRole)
 
    {
 
        switch(index.column())
 
        {
 
        case 0:
 
            return armyMap[army[index.row()]];
 
            break;
 
        case 1:
 
            return weaponTypeMap[weaponType[index.row()]];
 
            break;
 
        case 2:
 
            return weapon[index.row()];
 
        default:
 
            return QVariant();
 
        }
 
    }
 
    return QVariant();
 
}
 
 
QVariant ModelEx::headerData(int section, Qt::Orientation orientation, int role) const
 
{
 
    if(role==Qt::DisplayRole&&orientation==Qt::Horizontal)
 
        return header[section];
 
    return QAbstractTableModel::headerData(section,orientation,role);
 
}