Remove gui::
:
class gui : public QDialog{
Q_OBJECT
...
public slots:
void gui::on_go_clicked();
^^^^^
Remove it
题
I'm programming in QT 4.8.4 with C++. I want to have a drop-down menu, where I can select an option, and then it will run an exe with the selected item on the menu as the option for the exe.
Here's my code:
#ifndef GUI_H
#define GUI_H
#include <QDialog>
#include <QtGui>
class QLabel;
class QLineEdit;
class QPushButton;
class gui : public QDialog
{
Q_OBJECT
public:
gui(QWidget *parent = 0);
public slots:
void gui::on_go_clicked();
private:
QLabel *label1;
QLabel *label2;
QLineEdit *lineEdit;
QPushButton *goButton;
QComboBox cb;
};
#endif
And the .cpp file:
#include <QtGui>
#include <QApplication>
#include <QComboBox>
#include "gui.h"
#include <vector>
gui::gui(QWidget *parent) : QDialog(parent)
{
label1 = new QLabel(tr("Insert Name (Optional):"));
label2 = new QLabel(tr("Class Name (Required):"));
lineEdit = new QLineEdit;
goButton = new QPushButton(tr("&Go"));
goButton->setDefault(true);
connect(goButton, SIGNAL(clicked()), this, SLOT(on_go_clicked()));
QComboBox *cb = new QComboBox();
cb->addItem("Hello", "1");
cb->addItem("Test", "2");
QHBoxLayout *hLayout1 = new QHBoxLayout;
hLayout1->addWidget(label1);
hLayout1->addWidget(lineEdit);
QHBoxLayout *hLayout2 = new QHBoxLayout;
hLayout2->addWidget(label2);
hLayout2->addWidget(cb);
QHBoxLayout *hLayout3 = new QHBoxLayout;
hLayout3->addWidget(goButton);
hLayout3->addStretch();
QVBoxLayout *vLayout = new QVBoxLayout;
vLayout->addLayout(hLayout1);
vLayout->addLayout(hLayout2);
vLayout->addWidget(cb);
vLayout->addLayout(hLayout3);
setLayout(vLayout);
setWindowTitle(tr("TEST"));
setFixedHeight(sizeHint().height());
}
void gui::on_go_clicked()
{
QMessageBox::information(this, "ASDF", cb.currentText());
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
gui *stuff = new gui;
stuff->show();
return app.exec();
}
Right now I'm just trying to figure out how to use QComboBox, which isn't working. My code compiles, but when I run it I get "Object::connect: No such slot gui::on_go_clicked()"
I'm doing exactly what a tutorial says to do. I can't figure out why this isn't working.
解决方案
Remove gui::
:
class gui : public QDialog{
Q_OBJECT
...
public slots:
void gui::on_go_clicked();
^^^^^
Remove it
其他提示
I wonder why you code even compiles. No 'extra qualification on member on_go_clicked'. Remove gui:: from on_go_clicked in your header.
You have two QComboBox objects that you reference.
The first is at the class level:
class gui : public QDialog{
Q_OBJECT
public:
gui(QWidget *parent = 0);
public slots:
void gui::on_go_clicked();
private:
QLabel *label1;
QLabel *label2;
QLineEdit *lineEdit;
QPushButton *goButton;
QComboBox cb; // <<<=== class-level automatic object
};
The second is a local pointer-to-QComboBox object that exists in the constructor
gui::gui(QWidget *parent) : QDialog(parent){
...
QComboBox *cb = new QComboBox(); // <<<=== function-level pointer using the same name
// as the class-level automatic object
To correct the problem, you can change the class-level object to be a pointer and then change the object creation to be a simple assignment instead of a declaration-and-initialisation.
cb = new QComboBox();
Also, once you've done this, you'll need to modify the slot so that the pointer dereference operator is used to access the text()
function
void gui::on_go_clicked(){
QMessageBox::information(this, "ASDF", cb->currentText());
}