不管是哪种编程语言，在这里看不到一些系列的教程，当然也是由于笔者掌握的知识不够深，这里只会发送一些相关语言的实例，供大家参考学习。有时候笔者会分享一些自己觉得好的书籍，教学视频，或者好的学习网站给你们，这就需要你们有自学的能力，学习从来都不是件轻松的事，只有好好的坚持下去，才能成为大神。如果对于Qt有兴趣的伙伴，不妨去学习一下豆子博主的系列教程，会对你有所帮助。
//currencymodel.h
#ifndef CURRENCYMODEL_H
#define CURRENCYMODEL_H
#include <QAbstractTableModel>
#include <QVariant>
#include <QMap>
class CurrencyModel:public QAbstractTableModel
{
public:
CurrencyModel(QObject *parent=0);
void setCurrencyMap(const QMap<QString,double> &map);
int rowCount(const QModelIndex &parent) const;
int columnCount(const QModelIndex &parent) const;
QVariant data(const QModelIndex &index,int role) const;
QVariant headerData(int section, Qt::Orientation orientation, int role) const;
//可编辑模型实现
Qt::ItemFlags flags(const QModelIndex &index)const;
bool setData(const QModelIndex &index, const QVariant &value, int role=Qt::EditRole);
private:
QString currencyAt(int offset) const;
QMap<QString,double> currencyMap;
};
#endif // CURRENCYMODEL_H
//currencymodel.cpp
#include "currencymodel.h"
CurrencyModel::CurrencyModel(QObject *parent):QAbstractTableModel(parent)
{
}
//返回行数目
int CurrencyModel::rowCount(const QModelIndex &parent) const
{
return currencyMap.count();
}
//返回列数目
int CurrencyModel::columnCount(const QModelIndex &parent) const
{
return currencyMap.count();
}
//返回列名
//QVariant类将大部分类型(int,string)的数据封装起来，调用时使用to函数取出,例如：int类型包装成QVariant，用QVariant::toInt()取出
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();
}
//设置底层的实际数据，由于不可能将数据硬编码，所以必须为模型提供一个用于设置的函数
void CurrencyModel::setCurrencyMap(const QMap<QString, double> &map)
{
//两个函数为重置内部数据做准备
beginResetModel();
currencyMap=map;
endResetModel();
}
//返回单元格数据(只读模型)
//QVariant CurrencyModel::data(const QModelIndex &index,int role) const
//{
// if(!index.isValid()){
// return QVariant();
// }
// if(role==Qt::TextAlignmentRole){
// return int(Qt::DisplayRole | Qt::AlignCenter);
// }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();
//}
//(可编辑模型)
QVariant CurrencyModel::data(const QModelIndex &index,int role) const
{
if(!index.isValid()){
return QVariant();
}
if(role==Qt::TextAlignmentRole){
return int(Qt::DisplayRole | Qt::AlignCenter);
}else if(role==Qt::DisplayRole || role==Qt::EditRole){
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();
}
//可编辑模型函数实现
Qt::ItemFlags CurrencyModel::flags(const QModelIndex &index) const
{
Qt::ItemFlags flags=QAbstractItemModel::flags(index);
if(index.row()!=index.column()){
//按位或
flags |= Qt::ItemIsEditable;
}
return flags;
}
//更新数据
bool CurrencyModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
if(index.isValid()&&index.row()!=index.column()&&role==Qt::EditRole){
QString columnCurrency=headerData(index.column(),Qt::Horizontal,Qt::DisplayRole).toString();
QString rowCurrency=headerData(index.row(),Qt::Vertical,Qt::DisplayRole).toString();
currencyMap.insert(columnCurrency,value.toDouble()*currencyMap.value(rowCurrency));
emit dataChanged(index,index);
return true;
}
return false;
}
//main.cpp
#include <QApplication>
#include <currencymodel.h>
#include <QTableView>
int main(int argc, char *argv[])
{
QApplication a(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 a.exec();
}
