qt登录框

**Qt 登录框**

在 Qt 中，登录框是一种常见的用户界面组件，用于让用户输入用户名和密码以进行身份验证。下面是关于如何创建一个基本的登录框的教程。

###1. 创建登录框类首先，我们需要创建一个登录框类来管理登录过程。我们可以继承 `QWidget` 类来实现这个功能。

cpp// logindialog.h#ifndef LOGIN_DIALOG_H#define LOGIN_DIALOG_H#include 
#include 
#include 

class LoginDialog : public QWidget {
 Q_OBJECTpublic:
 explicit LoginDialog(QWidget *parent = nullptr);
 ~LoginDialog();

signals:

public slots:
 void onLoginButtonClicked();
};

#endif // LOGIN_DIALOG_H

cpp// logindialog.cpp#include "logindialog.h"
#include 
#include 
#include 
#include 

LoginDialog::LoginDialog(QWidget *parent) : QWidget(parent) {
 QVBoxLayout *layout = new QVBoxLayout(this);

 QLabel *usernameLabel = new QLabel(tr("Username:"), this);
 QLineEdit *usernameEdit = new QLineEdit(this);
 layout->addWidget(usernameLabel);
 layout->addWidget(usernameEdit);

 QLabel *passwordLabel = new QLabel(tr("Password:"), this);
 QLineEdit *passwordEdit = new QLineEdit(this);
 passwordEdit->setEchoMode(QLineEdit::Password);
 layout->addWidget(passwordLabel);
 layout->addWidget(passwordEdit);

 QPushButton *loginButton = new QPushButton(tr("&Login"), this);
 connect(loginButton, &QPushButton::clicked, this, &LoginDialog::onLoginButtonClicked);
 layout->addWidget(loginButton);

 setLayout(layout);
}

LoginDialog::~LoginDialog() {}

cppvoid LoginDialog::onLoginButtonClicked() {
 QString username = usernameEdit->text();
 QString password = passwordEdit->text();

 // 验证用户名和密码 if (username.isEmpty() || password.isEmpty()) {
 QMessageBox::information(this, tr("Error"), tr("Please enter both username and password."));
 return;
 }

 // 向服务器发送请求 QNetworkRequest request;
 request.setUrl(QUrl(" /> request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

 QByteArray data = QString("username=%1&password=%2").arg(username).arg(password);
 QNetworkReply *reply = manager->post(request, data);

 connect(reply, &QNetworkReply::finished, this, [this](QNetworkReply *reply) {
 if (reply->error() == QNetworkReply::NoError) {
 // 登录成功 QMessageBox::information(this, tr("Success"), tr("Login successful."));
 } else {
 // 登录失败 QMessageBox::critical(this, tr("Error"), reply->errorString());
 }
 });

 reply->ignoreHandler();
}

cppint main(int argc, char *argv[]) {
 QApplication app(argc, argv);

 LoginDialog loginDialog;
 loginDialog.exec();

 return app.exec();
}