Qt之界面切换（360、新浪、人人界面，多语化切换随心所欲）

通过点击底部栏的新浪、人人按钮来进行3个界面的相互切换，进行用户删除时，自定义的QDialog用于和用户交互，通过exec()可进入阻塞状态！详情请查看（Qt模态/非模态），translateLanguage()主要用于多语化的切换。。。

 在用Qt实现界面的时候，界面切换必不可少，如何实现呢？今天在这里分享一下自己的一些小心得！

实现界面切换主要用到：QStackedLayout、QWidget通过QStackedLayout的setCurrentWidget()来显示当前界面！

    当然还有其它的办法，好了，代码如下：

#include "login_dialog.h"
#include "util.h"
#include "account_item.h"

LoginDialog::LoginDialog(QWidget *parent)
 : QDialog(parent)
{
 this->resize(370, 275);
 this->setWindowFlags(Qt::FramelessWindowHint | Qt::Dialog);
 mouse_press = false;
 login = SAFE;
 sina_login = SINA;
 msg_box = new MsgBox(this);

 this->initRenRenWidget();
 this->initSafeWidget();
 this->initAuthorizeWidget();
 this->initSinaWidget();

 main_stacked_layout = new QStackedLayout();
 stacked_layout = new QStackedLayout();
 stacked_layout->addWidget(safe_widget);
 stacked_layout->addWidget(renren_widget);
 stacked_layout->setCurrentWidget(safe_widget);

 safe_renren_widget = new QWidget(this);
 title_label = new QLabel();
 account_label = new QLabel();
 password_label = new QLabel();
 other_account_label = new QLabel();
 close_button = new PushButton();
 sina_button = new QPushButton();
 renren_button = new QPushButton();
 register_button = new QPushButton();
 forgot_button = new QPushButton();
 login_button = new QPushButton();
 password_line_edit = new QLineEdit();
 remember_check_box = new QCheckBox();
 auto_login_check_box = new QCheckBox();

 title_label->setAlignment(Qt::AlignBottom);
 register_button->setCursor(Qt::PointingHandCursor);
 forgot_button->setCursor(Qt::PointingHandCursor);

 QPixmap sina_pixmap(":/loginDialog/sina");
 sina_button->setIcon(sina_pixmap);
 sina_button->setIconSize(QSize(20, 20));
 sina_button->setFixedSize(25, 22);

 QPixmap renren_pixmap(":/loginDialog/renren");
 renren_button->setIcon(renren_pixmap);
 renren_button->setIconSize(QSize(20, 20));
 renren_button->setFixedSize(25, 22);

 sina_button->setStyleSheet("border-radius:2px; border:1px solid rgb(180, 180, 180);");
 renren_button->setStyleSheet("border-radius:2px; border:1px solid rgb(180, 180, 180);");

 account_combo_box = new QComboBox();
 list_widget = new QListWidget();
 account_combo_box->setModel(list_widget->model());
 account_combo_box->setView(list_widget);
 account_combo_box->setEditable(true);
 for(int i=0; i<3; i++)
 {
  AccountItem *account_item = new AccountItem();
  account_item->setAccountNumber(QString("safe_") + QString::number(i, 10) + QString("@sina.com"));
  connect(account_item, SIGNAL(showAccount(QString)), this, SLOT(showAccount(QString)));
  connect(account_item, SIGNAL(removeAccount(QString)), this, SLOT(removeAccount(QString)));
  QListWidgetItem *list_item = new QListWidgetItem(list_widget);
  list_widget->setItemWidget(list_item, account_item);
 }

 account_label->setScaledContents(true);
 password_label->setScaledContents(true);
 account_label->setAlignment(Qt::AlignRight);
 password_label->setAlignment(Qt::AlignRight);
 password_line_edit->setEchoMode(QLineEdit::Password);
 account_combo_box->setFixedHeight(25);
 password_line_edit->setFixedHeight(25);

 close_button->loadPixmap(":/sysButton/close");
 title_label->setStyleSheet("color:white");
 register_button->setFixedSize(70, 25);
 forgot_button->setFixedSize(70, 25);
 login_button->setFixedSize(60, 25);
 register_button->setStyleSheet("color:green; background:transparent;");
 forgot_button->setStyleSheet("color:green; background:transparent;");
 login_button->setStyleSheet("QPushButton{border-radius:2px; border: 1px solid rgb(110, 180, 20); background:rgb(110, 190, 10); color:white;}"
  "QPushButton:hover{background:rgb(140, 220, 35);}");
 account_combo_box->setStyleSheet("QComboBox{border:1px solid rgb(180, 180, 180);}"
  "QComboBox QAbstractItemView::item{height:30px;}"
  "QComboBox::down-arrow{image:url(:/loginDialog/arrowDown);}"
  "QComboBox::drop-down{width:20px; border-left:1px solid rgb(180, 180, 180);}");
 password_line_edit->setStyleSheet("border:1px solid rgb(180, 180, 180);");
 QHBoxLayout *title_layout = new QHBoxLayout();
 title_layout->addWidget(title_label);
 title_layout->addStretch();
 title_layout->addWidget(close_button);
 title_layout->setSpacing(0);
 title_layout->setContentsMargins(10, 0, 5, 10);

 QHBoxLayout *h_layout = new QHBoxLayout();
 h_layout->addWidget(remember_check_box);
 h_layout->addWidget(auto_login_check_box);
 h_layout->addStretch();
 h_layout->setSpacing(40);
 h_layout->setContentsMargins(0, 0, 0, 0);

 QGridLayout *grid_layout = new QGridLayout();
 grid_layout->addWidget(account_label, 0, 0);
 grid_layout->addWidget(account_combo_box, 0, 1);
 grid_layout->addWidget(register_button, 0, 2);
 grid_layout->addWidget(password_label, 1, 0);
 grid_layout->addWidget(password_line_edit, 1, 1);
 grid_layout->addWidget(forgot_button, 1, 2);
 grid_layout->addLayout(h_layout, 2, 1);
 grid_layout->setHorizontalSpacing(5);
 grid_layout->setVerticalSpacing(10);
 grid_layout->setContentsMargins(20, 20, 20, 0);
 
 QHBoxLayout *login_layout = new QHBoxLayout();
 login_layout->addStretch();
 login_layout->addWidget(login_button);
 login_layout->setContentsMargins(0, 0, 20, 10);

 QHBoxLayout *bottom_layout = new QHBoxLayout();
 bottom_layout->addWidget(other_account_label);
 bottom_layout->addWidget(sina_button);
 bottom_layout->addWidget(renren_button);
 bottom_layout->addStretch();
 bottom_layout->setSpacing(5);
 bottom_layout->setContentsMargins(20, 0, 0, 5);

 QVBoxLayout *safe_renren_layout = new QVBoxLayout();
 safe_renren_layout->addLayout(stacked_layout);
 safe_renren_layout->addStretch();
 safe_renren_layout->addLayout(grid_layout);
 safe_renren_layout->addLayout(login_layout);
 safe_renren_layout->setSpacing(0);
 safe_renren_layout->setContentsMargins(0, 0, 0, 0);

 safe_renren_widget->setLayout(safe_renren_layout);

 main_stacked_layout->addWidget(safe_renren_widget);
 main_stacked_layout->addWidget(sina_widget);
 main_stacked_layout->setCurrentWidget(safe_renren_widget);

 QVBoxLayout *main_layout = new QVBoxLayout();
 main_layout->addLayout(title_layout);
 main_layout->addLayout(main_stacked_layout);
 main_layout->addLayout(bottom_layout);
 main_layout->setSpacing(0);
 main_layout->setContentsMargins(0, 0, 0, 0);

 this->setLayout(main_layout);

 connect(close_button, SIGNAL(clicked()), this, SLOT(hide()));
 connect(renren_button, SIGNAL(clicked()), this, SLOT(turnRenRen()));
 connect(sina_button, SIGNAL(clicked()), this, SLOT(turnSina()));

 this->translateLanguage();
}

void LoginDialog::initSinaWidget()
{
 sina_widget = new QWidget(this);
 sina_register_button = new QPushButton();
 
 sina_icon_label = new QLabel();
 sina_info_label = new QLabel();
 sina_net_label = new QLabel();
 sina_register_button = new QPushButton();
 sina_account_line_edit = new QLineEdit();
 sina_password_line_edit = new QLineEdit();
 examine_authorize_button = new QPushButton();
 authorize_button = new QPushButton();
 sina_login_check_box = new QCheckBox();
 safe_attention_check_box = new QCheckBox();

 sina_info_label->setAlignment(Qt::AlignBottom);
 sina_net_label->setAlignment(Qt::AlignTop);
 sina_register_button->setCursor(Qt::PointingHandCursor);
 examine_authorize_button->setCursor(Qt::PointingHandCursor);

 sina_account_line_edit->setFixedHeight(30);
 sina_password_line_edit->setFixedHeight(30);
 QPixmap icon_pixmap(":/loginDialog/sina");
 sina_icon_label->setPixmap(icon_pixmap);
 sina_icon_label->setFixedSize(icon_pixmap.size());
 sina_icon_label->setScaledContents(true);

 QFont sina_info_font = sina_info_label->font();
 sina_info_font.setPointSize(14);
 sina_info_font.setItalic(true);
 sina_info_label->setFont(sina_info_font);

 QFont sina_net_font = sina_net_label->font();
 sina_net_font.setItalic(true);
 sina_net_label->setFont(sina_net_font);

 sina_register_button->setStyleSheet("color:rgb(0, 120, 230); background:transparent;");
 sina_account_line_edit->setStyleSheet("border:1px solid rgb(180, 180, 180);");
 sina_password_line_edit->setStyleSheet("border:1px solid rgb(180, 180, 180);");
 examine_authorize_button->setStyleSheet("text-align:left; color:rgb(0, 120, 230); background:transparent;");
 authorize_button->setStyleSheet("border-radius:2px; border: 1px solid rgb(110, 180, 20); color:white; background:rgb(240, 50, 70);");

 authorize_button->setFixedSize(90, 30);
 QFont authorize_font = authorize_button->font();
 authorize_font.setPointSize(14);
 authorize_button->setFont(authorize_font);
 authorize_button->setStyleSheet("QPushButton{border-radius:2px; border: 1px solid rgb(230, 30, 40); color:white; background:rgb(240, 50, 70);}"
  "QPushButton:hover{background:rgb(255, 90, 100);}");

 QVBoxLayout *info_layout = new QVBoxLayout();
 info_layout->addWidget(sina_info_label);
 info_layout->addWidget(sina_net_label);
 info_layout->setSpacing(0);
 info_layout->setContentsMargins(0, 0, 0, 0);

 QHBoxLayout *sina_layout = new QHBoxLayout();
 sina_layout->addWidget(sina_icon_label);
 sina_layout->addLayout(info_layout);
 sina_layout->addStretch();
 sina_layout->setSpacing(5);
 sina_layout->setContentsMargins(0, 0, 0, 0);

 QGridLayout *grid_layout = new QGridLayout();
 grid_layout->addLayout(sina_layout, 0, 0);
 grid_layout->addWidget(sina_register_button, 0, 2);
 grid_layout->addWidget(sina_account_line_edit, 1, 0, 1, 3);
 grid_layout->addWidget(sina_password_line_edit, 2, 0, 1, 3);
 grid_layout->addWidget(examine_authorize_button, 3, 0);
 grid_layout->addWidget(authorize_button, 3, 2, Qt::AlignRight);
 grid_layout->setHorizontalSpacing(5);
 grid_layout->setVerticalSpacing(10);
 grid_layout->setContentsMargins(50, 0, 50, 0);

 QHBoxLayout *h_layout = new QHBoxLayout();
 h_layout->addStretch();
 h_layout->addWidget(sina_login_check_box);
 h_layout->addWidget(safe_attention_check_box);
 h_layout->setSpacing(20);
 h_layout->setContentsMargins(0, 0, 20, 0);

 QVBoxLayout *main_layout = new QVBoxLayout();
 main_layout->addLayout(grid_layout);
 main_layout->addLayout(h_layout);
 main_layout->setSpacing(20);
 main_layout->setContentsMargins(0, 0, 0, 0);

 connect(examine_authorize_button, SIGNAL(clicked()), this, SLOT(showAuthorize()));

 sina_widget->setLayout(main_layout);
}

void LoginDialog::initRenRenWidget()
{
 renren_widget = new QWidget(this);
 renren_icon_label = new QLabel();
 renren_info_label = new QLabel();
 renren_net_label = new QLabel();
 renren_login_label = new QLabel();

 QFont renren_info_font = renren_info_label->font();
 renren_info_font.setPointSize(14);
 renren_info_label->setFont(renren_info_font);

 QFont renren_login_font = renren_login_label->font();
 renren_login_font.setPointSize(14);
 renren_login_label->setFont(renren_login_font);

 renren_info_label->setStyleSheet("color:rgb(0, 90, 170);");
 renren_net_label->setStyleSheet("color:rgb(0, 90, 170);");
 renren_login_label->setStyleSheet("color:white;");

 QPixmap icon_pixmap(":/loginDialog/ren");
 renren_icon_label->setPixmap(icon_pixmap);
 renren_icon_label->setFixedSize(icon_pixmap.size());
 renren_icon_label->setScaledContents(true);

 QVBoxLayout *info_layout = new QVBoxLayout();
 info_layout->addStretch();
 info_layout->addWidget(renren_info_label);
 info_layout->addWidget(renren_net_label);
 info_layout->addStretch();
 info_layout->setSpacing(0);
 info_layout->setContentsMargins(0, 0, 0, 0);

 QHBoxLayout *main_layout = new QHBoxLayout();
 main_layout->addWidget(renren_icon_label);
 main_layout->addLayout(info_layout);
 main_layout->addStretch();
 main_layout->addWidget(renren_login_label);
 main_layout->setSpacing(5);
 main_layout->setContentsMargins(30, 0, 20, 0);

 renren_widget->setLayout(main_layout);
}

void LoginDialog::initSafeWidget()
{
 safe_widget = new QWidget(this);
 icon_label = new QLabel();
 safe_label = new QLabel();
 protect_label = new QLabel();

 safe_label->setAlignment(Qt::AlignRight);
 protect_label->setAlignment(Qt::AlignRight);
 QFont safe_font = safe_label->font();
 safe_font.setPointSize(14);
 safe_label->setFont(safe_font);
 safe_label->setStyleSheet("color:white");
 protect_label->setStyleSheet("color:white");

 icon_label->setFixedSize(70, 70);
 icon_label->setPixmap(QPixmap(":/img/360safe"));
 icon_label->setScaledContents(true);

 QVBoxLayout *info_layout = new QVBoxLayout();
 info_layout->addWidget(safe_label);
 info_layout->addWidget(protect_label);
 info_layout->addStretch();
 info_layout->setSpacing(5);
 info_layout->setContentsMargins(0, 0, 0, 0);

 QHBoxLayout *main_layout = new QHBoxLayout();
 main_layout->addWidget(icon_label);
 main_layout->addStretch();
 main_layout->addLayout(info_layout);
 main_layout->setSpacing(0);
 main_layout->setContentsMargins(30, 0, 20, 0);

 safe_widget->setLayout(main_layout);
}

void LoginDialog::initAuthorizeWidget()
{
 authorize_widget = new QWidget(this);
 authorize_widget->setFixedSize(100, 60);
 authorize_widget->installEventFilter(this);
 authorize_widget->hide();
}

void LoginDialog::showAuthorize()
{
 authorize_widget->showNormal();
 authorize_widget->raise();
 authorize_widget->activateWindow();
}

bool LoginDialog::eventFilter(QObject *obj, QEvent *event)
{
 if(obj == authorize_widget)
 {
  if(event->type() == QEvent::Paint)
  {
   QPainter painter(authorize_widget);
   painter.setPen(Qt::gray);
   static const QPointF points[4] = {QPointF(0, 30), QPointF(0, authorize_widget->height()-1), QPointF(authorize_widget->width()-1, authorize_widget->height()-1), QPointF(authorize_widget->width()-1, 30)};
   painter.drawPolygon(points, 4);
  }
 }

 return QWidget::eventFilter(obj, event);
}

LoginDialog::~LoginDialog()
{

}

void LoginDialog::translateLanguage()
{
 msg_box->translateLanguage();
 this->changeTitle();
 close_button->setToolTip(tr("close"));

 safe_label->setText(tr("360 safe"));
 protect_label->setText(tr("protect every day"));

 renren_info_label->setText(tr("renren"));
 renren_net_label->setText(tr("renren.com"));
 renren_login_label->setText(tr("login by renren"));

 account_label->setText(tr("account"));
 password_label->setText(tr("password"));
 other_account_label->setText(tr("other account"));
 register_button->setText(tr("register"));
 forgot_button->setText(tr("forgot"));
 login_button->setText(tr("login"));
 remember_check_box->setText(tr("remember"));
 auto_login_check_box->setText(tr("auto login"));

 sina_info_label->setText(tr("sina info"));
 sina_net_label->setText(tr("sina net"));
 sina_register_button->setText(tr("sina register"));
 examine_authorize_button->setText(tr("examine authorize"));
 authorize_button->setText(tr("authorize"));
 sina_login_check_box->setText(tr("sina login"));
 safe_attention_check_box->setText(tr("safe attention"));
 sina_account_line_edit->setPlaceholderText(tr("sina account"));
}

void LoginDialog::paintEvent(QPaintEvent *)
{
 bool is_sina = false;
 int width = this->width();
 int height = this->height();
 switch(login)
 {
 case SINA:
  is_sina = true;
  break;
 default:
  break;
 }

 int draw_height = 90;
 if(is_sina)
 {
  draw_height = 30;
 }

 QString skin_name;
 bool is_read = Util::readInit(QString("./user.ini"), QString("skin"), skin_name);
 if(is_read)
 {
  if(skin_name.isEmpty())
  {
   skin_name = QString(":/skin/17_big");
  }
 }
 else
 {
  skin_name = QString(":/skin/17_big");
 }

 QPainter painter(this);
 QBrush brush;
 brush.setTextureImage(QImage(skin_name));
 painter.setBrush(brush);
 painter.setPen(Qt::gray);  
 painter.drawRect(0, 0, this->width()-1, this->height()-1);

 int sina_line = 0;
 if(is_sina)
 {
  sina_line = 3;
  QLinearGradient linear(rect().topLeft(), rect().bottomRight());
  linear.setColorAt(0, QColor(240, 30, 50));
  linear.setColorAt(0.2, QColor(240, 40, 50));
  linear.setColorAt(0.4, QColor(255, 50, 60));
  linear.setColorAt(0.6, QColor(255, 150, 10));
  linear.setColorAt(0.8, QColor(255, 180, 60));
  linear.setColorAt(1, QColor(255, 200, 120));

  QPainter painter2(this);
  painter2.setBrush(QBrush(linear));
  painter2.setPen(Qt::NoPen);
  painter2.drawRect(QRect(1, draw_height+1, width-2, sina_line));
 }
 
 QPainter painter3(this);
 painter3.setPen(Qt::NoPen);
 painter3.setBrush(Qt::white);
 painter3.drawPolygon(QRect(1, draw_height+sina_line+1, width-2, height-draw_height-sina_line-2));
}

void LoginDialog::showAccount(QString account)
{
 account_combo_box->setEditText(account);
 account_combo_box->hidePopup();
}

void LoginDialog::removeAccount(QString account)
{
 msg_box->setInfo(tr("remove account"), tr("are you sure to remove account?"), QPixmap(":/loginDialog/attention"), false);
 if(msg_box->exec() == QDialog::Accepted)
 {
  int list_count = list_widget->count();
  for(int i=0; i
  {
   QListWidgetItem *item = list_widget->item(i);
   AccountItem *account_item = (AccountItem *)(list_widget->itemWidget(item));
   QString account_number = account_item->getAccountNumber();
   if(account == account_number)
   {
    list_widget->takeItem(i);
    delete item;

    break;
   }
  }
 }
}

void LoginDialog::mousePressEvent( QMouseEvent * event )
{
 //只能是鼠标左键移动和改变大小
 if(event->button() == Qt::LeftButton)
 {
  mouse_press = true;
 }

 //窗口移动距离
 move_point = event->globalPos() - pos();
}

void LoginDialog::mouseReleaseEvent(QMouseEvent *)
{
 mouse_press = false;
}

void LoginDialog::mouseMoveEvent(QMouseEvent *event)
{
 //移动窗口
 if(mouse_press)  
 {
  QPoint move_pos = event->globalPos();
  move(move_pos - move_point);
 }
}

void LoginDialog::turnRenRen()
{
 switch(login)
 {
 case SAFE:
  {
   if(sina_login == SINA)
   {
    login = RENREN;
   }
   else
   {
    login = SINA;
   }
   this->changeTitle();
   this->turnWidget();
   renren_button->setIcon(QIcon(":/img/safe"));
  }
  break;
 case RENREN:
  {
   if(sina_login == SINA)
   {
    login = SAFE;
   }
   else
   {
    login = SINA;
   } 
   this->changeTitle();
   this->turnWidget();
   renren_button->setIcon(QIcon(":/loginDialog/renren"));
  }
  break;
 case SINA:
  {
   if(sina_login == SAFE)
   {
    login = RENREN;
   }
   else
   {
    login = SAFE;
   } 
   this->changeTitle();
   this->turnWidget();
   renren_button->setIcon(QIcon(":/loginDialog/sina"));
  }
  break;

 default:
  break;
 }
}

void LoginDialog::turnSina()
{
 switch(login)
 {
 case SAFE:
  {
   if(sina_login == SINA)
   {
    login = SINA;
   }
   else
   {
    login = RENREN;
   }
   this->changeTitle();
   this->turnWidget();
   sina_login = SAFE;
   sina_button->setIcon(QIcon(":/img/safe"));
  }
  break;
 case RENREN:
  {
   if(sina_login == SINA)
   {
    login = SINA;
   }
   else
   {
    login = SAFE;
   }
   this->changeTitle();
   this->turnWidget();
   sina_login = RENREN;
   sina_button->setIcon(QIcon(":/loginDialog/renren"));
  }
  break;
 case SINA:
  {
   if(sina_login == SAFE)
   {
    login = SAFE;
    update();
   }
   else
   {
    login = RENREN;
   }
   this->changeTitle();
   this->turnWidget();
   sina_login = SINA;
   sina_button->setIcon(QIcon(":/loginDialog/sina"));
  }
  break;
 default:
  break;
 }
}

void LoginDialog::changeTitle()
{
 switch(login)
 {
 case SAFE:
  title_label->setText(tr("360 safe login"));
  break;
 case SINA:
  title_label->setText(tr("login by sina"));
  break;
 case RENREN:
  title_label->setText(tr("login by renren"));
  break;

 default:
  title_label->setText(tr("360 safe login"));
 }
}

void LoginDialog::turnWidget()
{
 switch(login)
 {
 case SAFE:
  {
   this->resize(370, 275);
   QWidget *current_widget = main_stacked_layout->currentWidget();
   if(current_widget == safe_renren_widget)
   {
    QWidget *stack_current_widget = stacked_layout->currentWidget();
    if(stack_current_widget != safe_widget)
    {
     stacked_layout->setCurrentWidget(safe_widget);
     register_button->show();
     forgot_button->show();
     auto_login_check_box->show(); 
    }
   }
   else
   {
    main_stacked_layout->setCurrentWidget(safe_renren_widget);
    QWidget *stack_current_widget = stacked_layout->currentWidget();
    if(stack_current_widget != safe_widget)
    {
     stacked_layout->setCurrentWidget(safe_widget);
     register_button->show();
     forgot_button->show();
     auto_login_check_box->show(); 
    }
   }
  }
  break;
 case SINA:
  {
   this->resize(400, 310);
   QWidget *current_widget = main_stacked_layout->currentWidget();
   if(current_widget == safe_renren_widget)
   {
    main_stacked_layout->setCurrentWidget(sina_widget);
   }
  }
  break;
 case RENREN:
  {
   this->resize(370, 275);
   QWidget *current_widget = main_stacked_layout->currentWidget();
   if(current_widget == safe_renren_widget)
   {
    QWidget *stack_current_widget = stacked_layout->currentWidget();
    if(stack_current_widget != renren_widget)
    {
     stacked_layout->setCurrentWidget(renren_widget);
     register_button->hide();
     forgot_button->hide();
     auto_login_check_box->hide(); 
    }
   }
   else
   {
    main_stacked_layout->setCurrentWidget(safe_renren_widget);
    QWidget *stack_current_widget = stacked_layout->currentWidget();
    if(stack_current_widget != renren_widget)
    {
     stacked_layout->setCurrentWidget(renren_widget);
     register_button->hide();
     forgot_button->hide();
     auto_login_check_box->hide(); 
    }
   }
  }
  break;

 default:
  break;
 } 
}