iso C++ forbids declaration of ""with no type 是什么原因 怒了

[40岁的码农也有春天]

#include <QtGui/QApplication>
#include "mainwindow.h"
#include <qwidget.h>
#include <qpushbutton.h>
#include <qfont.h>
#include <qlineedit.h>
#include <qstring.h>
class MyMainWindow : public QWidget
{
Q_OBJECT
public:
MyMainWindow();
public slots:
void CopyEdit(int);
private:
QPushButton *b1;
QPushButton *b2;
QPushButton *b3;
QLineEdit *ledit;
signals:
void valueChanged(int);
};
MyMainWindow::CopyEdit(int)
{
ledit->setText("this is a line of text!");
emit valueChanged(int);
connect(b2,SIGNAL(clicked()),ledit,SLOT(valueChanged(int)));
};
MyMainWindow::MyMainWindow()
{
this->setGeometry(300,300,400,400);
b1=new QPushButton("Click here to mark the tsxt",this);
b1->setGeometry(0,0,400,20);
b1->setFont(QFont("Times",10,QFont::Bold));
b2=new QPushButton("click here to unmark the text",this);
b2->setGeometry(0,25,400,20);
b2->setFont(QFont("Times",10,QFont::Bold));
b3=new QPushButton("click here to remove the text",this);
b3->setGeometry(0,50,400,20);
b3->setFont(QFont("Times",10,QFont::Bold));
ledit=new QLineEdit("this is a line of text!",this);
ledit->setGeometry(0,80,400,40);
connect(b1,SIGNAL(clicked()),ledit,SLOT(selectAll()));
//connect(b2,SIGNAL(clicked()),ledit,SLOT(CopyEdit()));
connect(b3,SIGNAL(clicked()),ledit,SLOT(clear()));

};

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyMainWindow w;
w.show();

return a.exec();
}

[40岁的码农也有春天]

提示如下:
iso C++ forbids declaration of "CopyEdit"with no type QT
prototype for "int MyMainWindow::CopyEdit(int)"dose not match any class"MyMainWindow"
cabdidate is "void MyMainWindow::CopyEdit(int)"

[donaldking]

好像是说父类里面（QWidget？）是int CopyEdit(int)而子类里面（MyMainWindow）是void CopyEdit(int)，这个两个函数不匹配，把MyMainWindow里面改成int CopyEdit(int)应该就好了。

[dbzhang800]

[Quote=引用楼主 tingzhongxiang 的回复:]
void MyMainWindow::CopyEdit(int)
{
ledit->setText("this is a line of text!");
emit valueChanged(int);
connect(b2,SIGNAL(clicked()),ledit,SLOT(valueChanged(int)));
};
[/Quote]
没什么好怒的，你自己没指定返回值。按照C的传统，默认就是int了。

[法尔我给他]

没指定返回值.

[gemfield]

[Quote=引用 1 楼 tingzhongxiang 的回复:]

提示如下:
iso C++ forbids declaration of "CopyEdit"with no type QT
prototype for "int MyMainWindow::CopyEdit(int)"dose not match any class"MyMainWindow"
cabdidate is "void MyMainWindow::CopyEdit(int)"……
[/Quote]
ISO/IEC 14882:1998 7.1.5第2小节有所描述

[zhangfl20]

也遇到同样的问题了

[icive]

遇到了同样的问题，指定返回值之后，就没有事儿了

[袁保康]

[Quote=引用 7 楼 的回复:]

遇到了同样的问题，指定返回值之后，就没有事儿了
[/Quote]
帮我解决了问题，谢谢；另加一句：就算没有返回值也要用个void