用QT设计登录、注册界面，并与MySQL连接，可进行用户名是否为英文检测，用户名重复检测。

 #include "Register.h" #include <QPushButton> #include <QString> #include <QMessageBox> #include<QPainter> #include<QtSql> registerwindow::registerwindow(QWidget * parent) :QDialog(parent) { //登陆界面定义 setWindowTitle(tr("注册界面")); setWindowIcon(QIcon(":/new/prefix1/Resources/Icon.gif")); //窗口只能最小化 this->setWindowFlags (this->windowFlags () | Qt::WindowMinimizeButtonHint|Qt::MSWindowsFixedSizeDialogHint); //成员初始化 UserName = new QLabel(tr("用户名：")); Password = new QLabel(tr("密 码：")); RePassword = new QLabel(tr("重复密码：")); UserNameEdit = new QLineEdit(); UserNameEdit->setPlaceholderText("请输入用户名"); PasswordEdit = new QLineEdit(); PasswordEdit->setPlaceholderText("请输入密码"); RePasswordEdit = new QLineEdit(); RePasswordEdit->setPlaceholderText("请再次输入密码"); //设置密码格式 PasswordEdit->setEchoMode(QLineEdit::Password); RePasswordEdit->setEchoMode(QLineEdit::Password); Mobile = new QLabel("手机号码："); MobileEdit = new QLineEdit(); MobileEdit->setPlaceholderText("请输入手机号码"); confirm = new QPushButton(tr("确认")); resetting = new QPushButton(tr("重置")); //实现上方信息网格布局 MessageLayout = new QGridLayout(); MessageLayout->addWidget(UserName,0,0); MessageLayout->addWidget(UserNameEdit,0,1); MessageLayout->addWidget(Password,1,0); MessageLayout->addWidget(PasswordEdit,1,1); MessageLayout->addWidget(RePassword,2,0); MessageLayout->addWidget(RePasswordEdit,2,1); MessageLayout->addWidget(Mobile,3,0); MessageLayout->addWidget(MobileEdit,3,1); //实现下方按钮网格布局 ButtonLayout = new QGridLayout(); ButtonLayout->addWidget(confirm,0,0); ButtonLayout->addWidget(resetting,0,1); ButtonLayout->setSpacing(20); //实现主网格 MainLayout = new QGridLayout(this); MainLayout->addLayout(MessageLayout,0,0); MainLayout->addLayout(ButtonLayout,1,0); MainLayout->setMargin(75); MainLayout->setSpacing(20); //连接信号和槽 connect(confirm,SIGNAL(clicked()),this,SLOT(confirm_slots())); connect(resetting,SIGNAL(clicked()),UserNameEdit,SLOT(clear())); connect(resetting,SIGNAL(clicked()),PasswordEdit,SLOT(clear())); connect(resetting,SIGNAL(clicked()),RePasswordEdit,SLOT(clear())); } //注册界面 void registerwindow::confirm_slots() { //-------------------------------------------------------- QString UName = UserNameEdit->text(); QString mobile = MobileEdit->text(); QString Pword; if(PasswordEdit->text()==RePasswordEdit->text()) { Pword = PasswordEdit->text(); //账号或密码不可为空 if(UName==""||Pword=="") { QMessageBox::information(this,"警告","用户名或密码不可为空！",QMessageBox::Ok); } else { if(IsEnglish(UName)) { qDebug()<<"全是英文，符合要求"<<endl; QString i=QString("insert into user values ('%1','%2','%3'); ").arg(UName).arg(Pword).arg(mobile); QString S =QString("select * from user where userName='%1' ").arg(UName); QSqlQuery query; if(query.exec(i)) QMessageBox::information(NULL, "注册成功", "注册成功！！！", QMessageBox::Yes); else if(query.exec(S)&&query.first()) QMessageBox::warning(NULL,"Error","用户名重复，请重试！！！"); else QMessageBox::warning(NULL,"Error","注册失败，请重试！！！"); this->close(); } else { QMessageBox::information(this,"提示","用户名不能含有中文哦！",QMessageBox::Ok); } } } else QMessageBox::warning(NULL,"Error","密码不重复，请重试！！！"); } //判断输入的字符是否全是英文 bool registerwindow::IsEnglish(QString &qstrSrc) { QByteArray ba=qstrSrc.toLatin1(); const char *s=ba.data(); bool bret=true; while (*s) { if((*s>='A'&&*s<='Z')||(*s>='a'&&*s<='z')) { } else { bret=false; break; } s++; } return bret; } registerwindow::~registerwindow() { } void registerwindow::paintEvent(QPaintEvent *event) { QPainter painter(this); painter.drawPixmap(0,0,width(),height(),QPixmap(":/new/prefix1/Resources/BJ.png")); }