error C2664: “QFileDialog::getOpenFileName”: 不能将参数1 从“const QString::Null”转换为“QWidget *”
以下程序运行时总出现上述问题
form.cpp
#include "form.h"
#include "QFileDialog.h"
form::form(QWidget *parent, Qt::WFlags flags)
: QWidget(parent, flags)
{
ui.setupUi(this);
}
form::~form()
{
}
void form::on_pushButton_clicked()
{
QString filename=QFileDialog::getOpenFileName( QString::null, QString::null, this );
}
form.h
#ifndef FORM_H
#define FORM_H
#include <QtGui/QWidget>
#include "ui_form.h"
class form : public QWidget
{
Q_OBJECT
public:
form(QWidget *parent = 0, Qt::WFlags flags = 0);
~form();
private:
Ui::formClass ui;
private slots:
void on_pushButton_clicked();
};
#endif // FORM_H
main.cpp
#include <QtGui/QApplication>
#include "form.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
form w;
w.show();
a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
return a.exec();
}
