Qt液晶显示器不工作

Posted 2023-02-17

【中文标题】Qt液晶显示器不工作

【英文标题】：Qt LCD display not working

【发布时间】：2014-06-23 06:41:14

【问题描述】：

一旦连接，我正在尝试将 http get 连接流的输出输出到液晶屏幕（未来的 http 股票行情）。我的代码错误“C:\Qt5\Tools\QtCreator\bin\httpGET\mainwindow.cpp:16: error: no matching function for call to 'QLCDNumber::display() ui->lcdNumber->display()” I我不确定如何正确更新 display()

//主窗口.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QNetworkAccessManager>
#include <QUrl>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QImageReader>
#include <QDebug>

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

    ui->setupUi(this);
    nam = new QNetworkAccessManager();
    ui->lcdNumber->display(10);



MainWindow::~MainWindow()

    delete ui;


void MainWindow::connect()

    QObject::connect(nam, SIGNAL(finished(QNetworkReply*)),
    this, SLOT(finishedSlot(QNetworkReply*)));

    //ui->lcdNumber->display(10);
    QObject::connect(nam, SIGNAL(finished(QNetworkReply*)),
    this, SLOT(on_pushButton_clicked()));



void MainWindow::requestPage()
    QUrl url("http://www.google.com");
    QNetworkReply* reply = nam->get(QNetworkRequest(url));


void MainWindow::finishedSlot(QNetworkReply* reply)
    QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
    QVariant redirectionTargetUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
    if (reply->error() == QNetworkReply::NoError)
    
        QImageReader imageReader(reply);
        QImage pic = imageReader.read();
        QByteArray bytes = reply->readAll();  // bytes
        QString string(bytes); // string
    

    else
    

    




void MainWindow::on_pushButton_clicked()

    connect();
    requestPage();

//主窗口.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QObject>
#include <QNetworkAccessManager>

namespace Ui 
class MainWindow;


class MainWindow : public QMainWindow

    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

private:
    Ui::MainWindow *ui;

public slots:
    void connect();
    void requestPage();
    void finishedSlot(QNetworkReply* reply);
    void on_pushButton_clicked();
private slots:

private:
    QNetworkAccessManager* nam;

;

#endif // MAINWINDOW_H

//main.cpp

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])

    QApplication a(argc, argv);

    MainWindow mConnect;
    mConnect.show();

    return a.exec();

【参考方案1】：

moving display() 修复了 lcd 输出问题。

if (reply->error() == QNetworkReply::NoError)

    QImageReader imageReader(reply);
    QImage pic = imageReader.read();
    QByteArray bytes = reply->readAll();  // bytes
    QString string(bytes); // string
    ui->lcdNumber->display(string);