Question

我想把重点放在QLineEdit控件上。为了做到这一点，我在子类控件中重新实现了focusInEvent。问题是，它只适用于使用键盘进行聚焦。使用TAB。如果我用鼠标点击它或点击它（因为它是一个嵌入式应用程序），它似乎根本没有抓住这个事件。

我已经尝试过设置focusPolicy但没有运气。

.cpp文件：

#include "foolineedit.h"
#include "ui_foolineedit.h"
#include <QDebug>
#include <QFocusEvent>

fooLineEdit::fooLineEdit(QWidget *parent) :
    QLineEdit(parent),
    ui(new Ui::fooLineEdit)
{
    ui->setupUi(this);
    this->setFocusPolicy(Qt::ClickFocus);
}

fooLineEdit::~fooLineEdit()
{
    delete ui;
}

void fooLineEdit::focusInEvent(QFocusEvent *e)
{
    qDebug() << e->reason();
    QLineEdit::focusInEvent(e);
    emit(focused(true));
}

.h文件：

#include <QWidget>
#include <QLineEdit>

namespace Ui {
class fooLineEdit;
}

class fooLineEdit : public QLineEdit
{
    Q_OBJECT

public:
    explicit fooLineEdit(QWidget *parent = 0);
    ~fooLineEdit();
signals:
    void focused(bool hasFocus);
protected:
    virtual void focusInEvent(QFocusEvent *e);
private:
    Ui::fooLineEdit *ui;
};

关于我做错了什么的任何想法？

修改

因为在评论中提到我添加了ui标题的代码清单

ui_foolineedit.h

class Ui_fooLineEdit
{
public:
    QLineEdit *lineEdit;

    void setupUi(QWidget *fooLineEdit)
    {
        if (fooLineEdit->objectName().isEmpty())
            fooLineEdit->setObjectName(QStringLiteral("fooLineEdit"));
        fooLineEdit->resize(151, 21);
        lineEdit = new QLineEdit(fooLineEdit);
        lineEdit->setObjectName(QStringLiteral("lineEdit"));
        lineEdit->setGeometry(QRect(0, 0, 151, 21));
        lineEdit->setFocusPolicy(Qt::ClickFocus);

        retranslateUi(fooLineEdit);

        QMetaObject::connectSlotsByName(fooLineEdit);
    } // setupUi

    void retranslateUi(QWidget *fooLineEdit)
    {
        fooLineEdit->setWindowTitle(QApplication::translate("fooLineEdit", "Form", Q_NULLPTR));
    } // retranslateUi

};

namespace Ui {
    class fooLineEdit: public Ui_fooLineEdit {};
} // namespace Ui

Answer 1

你基本上添加了一个

QLineEdit *lineEdit;

到您的fooLineEdit，而QLineEdit只是另一个setupUi。

这发生在lineEdit = new QLineEdit(fooLineEdit);：

fooLineEdit

我认为这足以让事情变得混乱（QLineEdit的事件处理程序永远等待 inner class fooLineEdit : public QLineEdit { Q_OBJECT public: explicit fooLineEdit(QWidget *parent = 0); signals: void focused(bool hasFocus); protected: virtual void focusInEvent(QFocusEvent *e); };内很可能发生的事件

尝试在不使用ui的情况下实现QLineEdit子类。

标题

fooLineEdit::fooLineEdit(QWidget *parent) :
    QLineEdit(parent)
{
    this->setFocusPolicy(Qt::ClickFocus);
}
void fooLineEdit::focusInEvent(QFocusEvent *e)
{
    qDebug() << e->reason();
    QLineEdit::focusInEvent(e);
    emit(focused(true));
}

来源：

span

看看问题是否已经消失。

Qt focusInEvent（）仅为键盘抓取焦点

1 个答案: