从屏幕上的小键盘输入时激活特定的 LineEdit

Question

我正在 qt 中创建一个登录表单，其中的输入是从小键盘获取的。小键盘是在屏幕上创建的。当我尝试从小键盘输入时，它接受两个 lineEdit 字段中的输入。那么如何在从小键盘输入时将这两者分开呢？

  #include "mainwindow.h"
#include "ui_mainwindow.h"
#include "mainscreen.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    connect(ui->dB1,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB2,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB3,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB4,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB5,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB6,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB7,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB8,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB9,SIGNAL(released()),this,SLOT(display()));
    connect(ui->dB0,SIGNAL(released()),this,SLOT(display()));


}

MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::display()
{
    QPushButton *qp=(QPushButton*)sender();
      ui->lineEdit->setText(ui->lineEdit->text()+qp->text());
      ui->lineEdit_2->setText(ui->lineEdit_2->text()+qp->text());
}


void MainWindow::on_pushButton_clicked()
{
    QString username=ui->lineEdit->text();
    QString password=ui->lineEdit_2->text();

    if(username=="text"&&password=="text")
    {
     hide();
     main_scn=new MainScreen();
     main_scn->setWindowFlags(Qt::Window|Qt::FramelessWindowHint);
     main_scn->show();

    }
}

UI在这里，请查看

Answer 1

以这种方式创建小键盘很不方便，因为它会将文本放在两个 QLineEdit 中，而且通常用户名和密码并不总是相同。

我的建议是创建一个数字小键盘，不需要通过信号连接，但会发送一个事件，以便获得焦点的小部件。

numpadwidget.h

#ifndef NUMPADWIDGET_H
#define NUMPADWIDGET_H

#include <QApplication>
#include <QGridLayout>
#include <QKeyEvent>
#include <QToolButton>
#include <QWidget>

class NumpadWidget : public QWidget
{
    Q_OBJECT
public:
    explicit NumpadWidget(QWidget *parent = nullptr) : QWidget(parent)
    {
        QGridLayout *lay = new QGridLayout(this);

        const std::vector<QPair<QString, int>> values{{"1", Qt::Key_1}, {"2", Qt::Key_2}, {"3", Qt::Key_3},
                                                      {"4", Qt::Key_4}, {"5", Qt::Key_5}, {"6", Qt::Key_6},
                                                      {"7", Qt::Key_7}, {"8", Qt::Key_8}, {"9", Qt::Key_9},
                                                      {".", Qt::Key_Colon}, {"0", Qt::Key_0}, {"*", Qt::Key_Asterisk}};

        int i = 0;
        int j = 0;

        for(const QPair<QString, int> & value : values){
            QToolButton *button =new QToolButton;
            button->setText(value.first);
            button->setFixedSize(40,40);
            lay->addWidget(button, i, j);
            button->setProperty("text", value.first);
            button->setProperty("key", value.second);
            connect(button, &QToolButton::clicked, this, &NumpadWidget::onClicked);
            j++;
            if(j % 3 == 0){
                j=0;
                i++;
            }
        }
        setFixedSize(sizeHint());
    }
private slots:
    void onClicked()
    {
        if(QWidget *widget = QApplication::focusWidget()){
            QString text = sender()->property("text").toString();
            int key = sender()->property("key").toInt();
            QKeyEvent * event = new QKeyEvent(QEvent::KeyPress, key, Qt::NoModifier, text);
            QCoreApplication::postEvent(widget, event);
        }
    }
};

#endif // NUMPADWIDGET_H

然后将NumpadWidget提升到可以在Qt Designer中使用，下面link说明具体方法

完整的项目可以在下面找到link。

从屏幕上的小键盘输入时激活特定的 LineEdit

Activating particular LineEdit while taking input from on screen numpad

c++

qt

qlineedit

qt5