Question

我是Qt Framework的新手，我还在学习。在搜索教程时，我偶然发现了一系列教授Qt基础知识的视频以及制作计算器的项目。虽然计算器似乎工作正常，但我得到了这种警告

QMetaObject::connectSlotsByName: No matching signal for on_pushButton_unary_released()
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_binary_released()

我已经尝试了一切，但似乎没有任何工作。我真的很沮丧。任何帮助都将不胜感激。顺便说一下，我附上了mainwindow.cpp的代码

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

double firstnum ;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{

    ui->setupUi(this);
   connect(ui->pushButton_0 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_1 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_2 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_3 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_4 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_5 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_6 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_7 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_8 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_9 , SIGNAL(released()),this,SLOT(digits_released()));
   connect(ui->pushButton_plusminus , SIGNAL(released()),this,SLOT(on_pushButton_unary_released()));
   connect(ui->pushButton_percent , SIGNAL(released()),this,SLOT(on_pushButton_unary_released()));
   connect(ui->pushButton_plus , SIGNAL(released()),this,SLOT(on_pushButton_binary_released()));
   connect(ui->pushButton_minus, SIGNAL(released()),this,SLOT(on_pushButton_binary_released()));
   connect(ui->pushButton_multiply , SIGNAL(released()),this,SLOT(on_pushButton_binary_released()));
   connect(ui->pushButton_divide , SIGNAL(released()),this,SLOT(on_pushButton_binary_released()));

   ui->pushButton_divide->setCheckable(true);
   ui->pushButton_minus->setCheckable(true);
   ui->pushButton_plus->setCheckable(true);
   ui->pushButton_multiply->setCheckable(true);

}

MainWindow::~MainWindow()
{
    delete ui;

}

void MainWindow::digits_released(){
  QPushButton *button = (QPushButton*)sender();
  double labelNumber ;
  QString newLabel ;
  if(ui->pushButton_plus->isChecked() || ui->pushButton_minus->isChecked()
     || ui->pushButton_divide->isChecked()
     || ui->pushButton_multiply->isChecked())
  {
      labelNumber = button->text().toDouble();
  }
  else
  {
  labelNumber = (ui->label->text() + button->text()).toDouble();
  newLabel = QString::number(labelNumber, 'g' , 15);
  ui->label->setText(newLabel);
  }
}

void MainWindow::on_pushButton_decimal_released()
{
    QString decimal = QString(".");
    if (ui->label->text().contains(decimal))
    {
    }
    else
    {
    ui->label->setText(ui->label->text() + ".");
    }
}

void MainWindow::on_pushButton_unary_released()
{
    QPushButton * button = (QPushButton*) sender();
    double labelNumber ;
    QString newLabel ;

    if (button->text() == "+/-")
    {
        labelNumber = ui->label->text().toDouble();
        labelNumber = labelNumber * -1 ;
        newLabel = QString::number(labelNumber, 'g' , 15);
        ui->label->setText(newLabel);
    }
    else if (button->text() == "%") {
        labelNumber = ui->label->text().toDouble();
        labelNumber = labelNumber * 0.01  ;
        newLabel = QString::number(labelNumber, 'g' , 15);
        ui->label->setText(newLabel);
    }
}

void MainWindow::on_pushButton_C_released()
{
    ui->label->setText("0");
}

void MainWindow::on_pushButton_binary_released()
{
    QPushButton * button = (QPushButton*) sender();
    firstnum = ui->label->text().toDouble();
    button->setChecked(true);
}

void MainWindow::on_pushButton_equal_released()
{
    double secondnum , labelNumber ;
    QString  newlabel ;
    secondnum = ui->label->text().toDouble();
    if (ui->pushButton_plus->isChecked())
    {
        labelNumber = firstnum + secondnum ;
        newlabel = QString::number(labelNumber , 'g' , 15);
        ui->label->setText(newlabel);
        ui->pushButton_plus->setChecked(false);

    }
    else if (ui->pushButton_minus->isChecked())
    {
        labelNumber = firstnum - secondnum ;
        newlabel = QString::number(labelNumber , 'g' , 15);
        ui->label->setText(newlabel);
        ui->pushButton_minus->setChecked(false);
    }
    else if (ui->pushButton_divide->isChecked())
    {
        labelNumber = firstnum / secondnum ;
        newlabel = QString::number(labelNumber , 'g' , 15);
        ui->label->setText(newlabel);
        ui->pushButton_divide->setChecked(false);
    }
    else if (ui->pushButton_multiply->isChecked())
    {
        labelNumber = firstnum * secondnum ;
        newlabel = QString::number(labelNumber , 'g' , 15);
        ui->label->setText(newlabel);
        ui->pushButton_multiply->setChecked(false);
    }
}

Answer 1

名为*＆＃34; on_something **的插槽由QMetaObject以特殊方式处理，它使用It的反射机制将它们连接到正确的控制和信号。

sintax实际上是on_objectName_signal。因此，您在控制台中看到的错误是因为moc没有找到名为＆＃34; pushButton_unary＆＃34;的对象。尝试自动连接。

由于您手动将信号连接到插槽，因此只需重命名插槽即可避免使用该语法（例如，将插槽命名为＆＃34; onUnaryButtonRelesed＆＃34;）。

QMetaObject :: connectSlotsByName：对于合法代码没有匹配的信号警告

1 个答案: