自定义只读模型

,cpp文件源码

#include "currencymodel.h"

CurrencyModel::CurrencyModel(QObject *parent)
: QAbstractTableModel(parent)
{


}


CurrencyModel::~CurrencyModel()
{


}


int CurrencyModel::rowCount(const QModelIndex &parent) const 
{
return currencyMap.count();  
}
 
int CurrencyModel::columnCount(const QModelIndex & parent)const
{
return currencyMap.count(); 
} 
QVariant CurrencyModel::headerData( int section,Qt::Orientation,int role) const 
{
if (role !=Qt::DisplayRole)
{
return QVariant(); 
} 
return currencyAt(section); 
} 
QString CurrencyModel::currencyAt(int offset) const 
{
return(currencyMap.begin()+offset).key(); 
} 
void CurrencyModel::setCurrencyMap(const QMap<QString,double> &map)
{
beginResetModel();     // 写一种协议 
currencyMap = map; 
endResetModel();
}


QVariant CurrencyModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid()) {
return QVariant();
}


if (role == Qt::TextAlignmentRole) {
return int(Qt::AlignRight | Qt::AlignVCenter);
}
else if (role == Qt::DisplayRole) {
QString rowCurrency = currencyAt(index.row());
QString columnCurrency = currencyAt(index.column());
if (currencyMap.value(rowCurrency) == 0.0) {
return "####";
}
double amount = currencyMap.value(columnCurrency)
/ currencyMap.value(rowCurrency);
return QString("%1").arg(amount, 0, 'f', 4);
}
return QVariant();
} 

.h  文件源码  

#ifndef CURRENCYMODEL_H
#define CURRENCYMODEL_H

#include <QAbstractTableModel>


class CurrencyModel : public QAbstractTableModel
{
Q_OBJECT


public:
CurrencyModel(QObject *parent=0); 
~CurrencyModel(); 


void setCurrencyMap(const QMap<QString, double> &map);   // 非const的成员函数不可以被const的对象访问 


int rowCount(const QModelIndex &parent) const;   // this指针常量化  任何修改this成员变量的操作都是不允许的  即可被const对象访问也可以被非const对象访问


int columnCount(const QModelIndex &parent) const;


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


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


private:


QString currencyAt(int offset) const;


QMap<QString, double> currencyMap;

};


#endif // CURRENCYMODEL_H

mian 函数的实现代码 ：

int main(int argc, char *argv[])
{
QApplication   app(argc, argv);

QMap<QString, double> data;
data["USD"] = 1.0000;
data["CNY"] = 0.1628;
data["GBP"] = 1.5361;
data["EUR"] = 1.2992;
data["HKD"] = 0.1289;


QTableView view;
CurrencyModel *model = new CurrencyModel(&view);
model->setCurrencyMap(data);
view.setModel(model);
view.resize(400, 300);
view.show();   

return app.exec();


}

实现效果： 

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intmain(intargc,char*argv[])

{

    QApplicationa(argc,argv);

 

    QMap<QString,double>data;

    data["USD"]=1.0000;

    data["CNY"]=0.1628;

    data["GBP"]=1.5361;

    data["EUR"]=1.2992;

    data["HKD"]=0.1289;

 

    QTableViewview;

    CurrencyModel *model=newCurrencyModel(&view);

    model->setCurrencyMap(data);

    view.setModel(model);

    view.resize(400,300);

    view.show();

 

    returna.exec();

}