Question

您好我正在尝试在Qt中编写模板类，而这样做我遇到了一些错误，我已经阅读了一些文章并开始根据我的要求构建示例

template.h

#ifndef CSLCDTEMPLATE_H
#define CSLCDTEMPLATE_H

#include <QDialog>
#include <QTimer>
#include <QDebug>
#include <QList>
#include <QPixmap>
#include <QPalette>
#include <QStringList>


template<class T>
class LcdTemplate : public QDialog
{
public:
    LcdTemplate();
    void display(T);
    T Getalue();

private slots:
    void display();
private:
    int indexVal;
    T m_Obj;
    QStringList nameList;
};

#endif
// CSLCDTEMPLATE_H

template.cpp

#include "CSLcdTemplate.h"

extern QStringList display_list;

template <class T>
LcdTemplate<T>::LcdTemplate()
{
    qDebug()<<"Inside the Constructor of LCD Template";

    setWindowFlags(Qt::FramelessWindowHint);
#ifdef GL11_QT
    setGeometry(0,0,320,240);
#endif
#ifdef GL11_GNOME
    setGeometry(2,20,316,200);
#endif
    setStyleSheet("background-color:yellow");

    indexVal = 0;

    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(display()));
    timer->start(500);

    QTimer::singleShot(4000, this, SLOT(close()));
}

//template <class T>
void LcdTemplate::display()
{

    nameList = display_list;
    qDebug()<<"Data in"<<nameList;
    display(nameList);

}

template <class T>
void LcdTemplate<T>::display(T list)
{
    switch(indexVal)
    {
    case 0:
        this->setStyleSheet(nameList.at(indexVal));
        indexVal = 1;
        break;
    case 1:
        this->setStyleSheet(nameList.at(indexVal));
        indexVal = 2;
        break;
    case 2:
        this->setStyleSheet(nameList.at(indexVal));
        indexVal = 3;
        break;
    case 4:
        this->setStyleSheet(nameList.at(indexVal));
        indexVal = 4;
        break;
    case 5:
        this->setStyleSheet(nameList.at(indexVal));
        indexVal = 0;
        break;
    }
}

template <class T>
T TestTemp<T>::Getalue()
{
   return m_Obj;
}

我面临的错误是

CSLcdTemplate.cpp:29:6: error: 'template<class T> class LcdTemplate' used without template parameters
CSLcdTemplate.cpp: In function 'void display()':
CSLcdTemplate.cpp:32:5: error: 'nameList' was not declared in this scope
CSLcdTemplate.cpp: At global scope:
CSLcdTemplate.cpp:67:11: error: expected initializer before '<' token

如何解决此错误。

Answer 1

不要混合模板类和负责信号和插槽的类。见this

请注意，模板类成员定义的正确语法是

template <class T>
void LcdTemplate<T>::display()
{}

请注意，您还需要添加Q_OBJECT宏以使信号和插槽正常工作。

如何在Qt中解决模板问题

1 个答案: