多个定义错误：一个在我的文件中，一个在 moc 文件中。

我有一个名为 FindAndReplaceBar 的类，其实现是这样的：

#include "FindAndReplaceBar.h"
#include <QLabel>
#include <QPushButton>
#include <QGridLayout>
#include <QTextDocument>
#include <QLineEdit>

FindAndReplaceBar::FindAndReplaceBar(QObject *parent) :
    QToolBar(NULL)
{
    lblFind         = new QLabel("Find: ",this);
    lblReplace      = new QLabel("Replace",this);

    ledtFind        = new QLineEdit(this);
    ledtReplace     = new QLineEdit(this);

    QPixmap next(":/res/resources/next.gif");
    QPixmap previous(":/res/resources/previous.gif");
    QPixmap close(":/res/resources/close_icon.gif");

    btnFindNext     = new QPushButton(QIcon(next),"",this);
    btnFindPrevious = new QPushButton(QIcon(previous),"",this);
    btnClose        = new QPushButton(QIcon(close),"",this);

    btnReplace      = new QPushButton("Replace",this);
    btnReplaceAll   = new QPushButton("Replace All",this);

    btnFindNext->setFlat(true);
    btnFindPrevious->setFlat(true);
    btnClose->setFlat(true);
    btnReplace->setFlat(true);
    btnReplaceAll->setFlat(true);

    lytFindAndReplaceBar        = new QGridLayout(this);

    lytFindAndReplaceBar->addWidget(lblFind,0,0,1,1);
    lytFindAndReplaceBar->addWidget(ledtFind,0,1,1,2);
    lytFindAndReplaceBar->addWidget(btnFindPrevious,0,3,1,1);
    lytFindAndReplaceBar->addWidget(btnFindNext,0,4,1,1);

    lytFindAndReplaceBar->addWidget(lblReplace,0,5,1,1);
    lytFindAndReplaceBar->addWidget(ledtReplace,0,6,1,2);
    lytFindAndReplaceBar->addWidget(btnReplace,0,8,1,1);
    lytFindAndReplaceBar->addWidget(btnReplaceAll,0,9,1,1);

    this->setLayout(lytFindAndReplaceBar);

    connect(btnFindNext,SIGNAL(clicked()),this,SIGNAL(findNext()));
    connect(btnFindPrevious,SIGNAL(pressed()),this,SIGNAL(findPrevious()));
    connect(btnClose,SIGNAL(pressed()),this,SLOT(close()));
    connect(btnReplace,SIGNAL(pressed()),this,SIGNAL(replace()));
    connect(btnReplaceAll,SIGNAL(pressed()),this,SIGNAL(replaceAll()));

    this->setStyleSheet("QToolBar{background: qlineargradient(x1:0,x2:0,y1:0,y2:1,stop:0 #fffaf0,stop:0.3 #fdf5e6)} QLineEdit{border-radius:4px;padding:2px;}");
}

void FindAndReplaceBar::findNext()
{
    emit find(0);
}

void FindAndReplaceBar::findPrevious()
{
    emit find(QTextDocument::FindBackward);
}

void FindAndReplaceBar::replace()
{
    emit replace(false);
}

void FindAndReplaceBar::replaceAll()
{
    emit replace(true);
}

QString FindAndReplaceBar::searchTerm()
{
    return this->ledtFind->text();
}

QString FindAndReplaceBar::replaceTerm()
{
    return this->ledtReplace->text();
}

void FindAndReplaceBar::setSearchFieldText(const QString & searchFieldText)
{
    this->ledtFind->setText(searchFieldText);
}

void FindAndReplaceBar::setReplaceFieldText(const QString & replaceFieldText)
{
    this->ledtReplace->setText(replaceFieldText);
}

当我运行该程序时，我遇到了函数的多个定义的问题：

findNext(), findPrevious(), replace(), replaceAll().

另一个定义是在 moc_FindAndReplaceBar.cpp 文件中进行的。 我不确定问题是什么，所以我不知道如何解决它！我真的很感激任何帮助，谢谢！

根据您的连接调用（信号到信号）判断，我假设如果我们查看您的头文件，您将声明findNext(), findPrevious(), replace(), replaceAll() as signals, but 你不能执行信号- 它们只需要在标头中声明即可。

从 Qt 文档开始signals http://doc.qt.io/archives/qt-4.8/signalsandslots.html#signals

信号由 moc 自动生成，不得 在.cpp 文件中实现。它们永远不能有返回类型（即 使用无效）。