c++ - 在 Qt 中显示对话框的密码

Question

我需要像这样创建一个登录对话框

图片文件:eyeOn.png, eyeOff.png

要求:

• 仅当我们单击并按住 eyeOn 图标时才显示密码(即使我们单击并按住鼠标并将其拖动到对话框之外的区域时，密码仍会显示)，当我们松开鼠标时，密码将再次被覆盖.
• 显示密码时，眼睛图标为 eyeOn。当密码被覆盖时，眼睛图标是 eyeOff。

我刚刚构建了布局。

QGridLayout *mainlogin = new QGridLayout();

QLabel *usernameLabel = new QLabel;
usernameLabel->setWordWrap(true);
usernameLabel->setText("Username");
mainlogin->addWidget(usernameLabel, 0, 0);

QComboBox *usernameLineEdit = new QComboBox;
usernameLineEdit->setEditable(true);
usernameLabel->setBuddy(usernameLineEdit);
mainlogin->addWidget(usernameLineEdit, 0, 1);

QLabel *capslockShow = new QLabel;
capslockShow->setWordWrap(true);
capslockShow->setText(" ");
mainlogin->addWidget(capslockShow, 1, 1);

QLabel *passwordLabel = new QLabel;
passwordLabel->setWordWrap(true);
passwordLabel->setText("Password");
mainlogin->addWidget(passwordLabel, 2, 0);
QLineEdit *passwordLineEdit = new QLineEdit;
passwordLineEdit->setEchoMode(QLineEdit::Password);
QAction *myAction = passwordLineEdit->addAction(QIcon(":/eyeOff.png"), QLineEdit::TrailingPosition);
passwordLabel->setBuddy(passwordLineEdit);
mainlogin->addWidget(passwordLineEdit, 2, 1);

接下来我该做什么？请帮助我编写代码片段。

Answer 1

解决方案是在QLineEdit中添加一个QAction，这将创建一个QToolButton，我们可以从associatedWidgets中获取它()(它将是第二个小部件，因为第一个小部件是与 clearButton 关联的小部件)。已经有了 QToolButton，您必须使用 pressed 和 released 信号。

passwordlineedit.h

#ifndef PASSWORDLINEEDIT_H
#define PASSWORDLINEEDIT_H

#include <QAction>
#include <QLineEdit>
#include <QToolButton>

class PasswordLineEdit: public QLineEdit
{
public:
    PasswordLineEdit(QWidget *parent=nullptr);
private slots:
    void onPressed();
    void onReleased();
protected:
    void enterEvent(QEvent *event);
    void leaveEvent(QEvent *event);
    void focusInEvent(QFocusEvent *event);
    void focusOutEvent(QFocusEvent *event);
private:
    QToolButton *button;
};

#endif // PASSWORDLINEEDIT_H

passwordlineedit.cpp

#include "passwordlineedit.h"

PasswordLineEdit::PasswordLineEdit(QWidget *parent):
    QLineEdit(parent)
{
    setEchoMode(QLineEdit::Password);
    QAction *action = addAction(QIcon(":/eyeOff"), QLineEdit::TrailingPosition);
    button = qobject_cast<QToolButton *>(action->associatedWidgets().last());
    button->hide();
    button->setCursor(QCursor(Qt::PointingHandCursor));
    connect(button, &QToolButton::pressed, this, &PasswordLineEdit::onPressed);
    connect(button, &QToolButton::released, this, &PasswordLineEdit::onReleased);
}

void PasswordLineEdit::onPressed(){
    QToolButton *button = qobject_cast<QToolButton *>(sender());
    button->setIcon(QIcon(":/eyeOn"));
    setEchoMode(QLineEdit::Normal);
}

void PasswordLineEdit::onReleased(){
    QToolButton *button = qobject_cast<QToolButton *>(sender());
    button->setIcon(QIcon(":/eyeOff"));
    setEchoMode(QLineEdit::Password);
}

void PasswordLineEdit::enterEvent(QEvent *event){
    button->show();
    QLineEdit::enterEvent(event);
}

void PasswordLineEdit::leaveEvent(QEvent *event){
    button->hide();
    QLineEdit::leaveEvent(event);
}

void PasswordLineEdit::focusInEvent(QFocusEvent *event){
    button->show();
    QLineEdit::focusInEvent(event);
}

void PasswordLineEdit::focusOutEvent(QFocusEvent *event){
    button->hide();
    QLineEdit::focusOutEvent(event);
}

完整的例子可以在下面link下载.