第50课 关于对话框(About)
1. 关于对话框
（1）标准的桌面应用软件都有一个关于对话框
（2）关于对话框用于标识软件自身的信息。如logo、项目名、版本号、开发者信息、版权信息、联系方式等。
2. 经典设计方案
3. 项目持续开发
（1）自定义文本编辑框中的字体大小及实现思路
①通过QFontDialog选择字体以及大小
②将QFont对象设置到文本编辑框
（2）设置文本编辑框是否自动换行及实现思路
①获取当前文本编辑框的换行模式
②将模式进行反转后并进行设置
③更新对应QAction对象的状态
（3）打开外部帮助文件及实现思路
①QDesktopServices提供了一系列桌面开发相关的服务接口
②通过QDesktopServices中的成员函数打开帮助文件：QDesktopServices::openUrl(QUrl("path"));
【编程实验】关于对话框的创建及项目持续开发
//main.cpp、FontDialog.h(cpp)、ReplaceDialog.h(cpp)与上例相同
//AboutDialog.h
#ifndef _ABOUTDIALOG_H_
#define _ABOUTDIALOG_H_
#include <QDialog>
#include <QLabel>
#include <QPlainTextEdit>
#include <QPushButton>
class AboutDialog : public QDialog
{
Q_OBJECT
QLabel m_logoLbl;
QLabel m_qqLbl;
QPlainTextEdit m_infoEdit;
QPushButton m_closeBtn;
public:
);
};
#endif // _ABOUTDIALOG_H_
//AboutDialog.cpp
#include "AboutDialog.h"
#include <QPalette>
#include <QPixmap>
AboutDialog::AboutDialog(QWidget* parent):
QDialog(parent, Qt::WindowCloseButtonHint),
m_logoLbl(this),m_qqLbl(this),m_infoEdit(this),m_closeBtn(this)
{
QPixmap pm(":/Res/pic/dt.png");
pm = pm.scaled(,,Qt::KeepAspectRatio);
m_logoLbl.setPixmap(pm);
m_logoLbl.move(, );
m_logoLbl.resize(, );
//使m_infoEdit的背景透明的方法：
//1.使用调色板
// QPalette p = m_infoEdit.palette();
// p.setColor(QPalette::Active, QPalette::Base, palette().color(QPalette::Active,
// QPalette::Background));
// p.setColor(QPalette::Inactive, QPalette::Base, palette().color(QPalette::Inactive,
// QPalette::Background));
// m_infoEdit.setPalette(p);
//2.方法2
//m_infoEdit.setStyleSheet("background-color: rgb(255, 255, 255, 0);");
//3.方法3
m_infoEdit.setStyleSheet("background-color:transparent;");
m_infoEdit.move(,);
m_infoEdit.resize(, );
m_infoEdit.setFrameStyle(QFrame::NoFrame);
m_infoEdit.setReadOnly(true);
m_infoEdit.insertPlainText("Note Pad Project\n\nPlatform:Qt 5.6.0\n\nVersion:1.0.0\n\nCopyright:D.T.Software");
m_qqLbl.move(, );
m_qqLbl.setText("QQ Group: 199546072");
m_closeBtn.setText("Close");
m_closeBtn.move(, );
m_closeBtn.resize(, );
setFixedSize(, );
setWindowTitle("About NotePad");
connect(&m_closeBtn, SIGNAL(clicked()), this, SLOT(close()));
}
//MainWindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QMenuBar>
//#include <QKeySequence>
//#include <QAction>
#include <QPlainTextEdit>
#include <QLabel>
#include <QFileDialog>
#include <QSharedPointer>
#include "FindDialog.h"
#include "ReplaceDialog.h"
class MainWindow : public QMainWindow
{
Q_OBJECT
private:
QPlainTextEdit mainEditor;
QLabel statusLbl;
QString m_filePath;//当前操作的文件路径
bool m_isTextChanged; //标识编辑框中的内容是否改变
QSharedPointer<FindDialog> m_pFindDlg;//组合关系，利用智能指针来管理其生命周期
QSharedPointer<ReplaceDialog> m_pRelaceDlg;
//将构造函数、复制构造、赋值函数等私有化
MainWindow(QWidget *parent = );
MainWindow(const MainWindow&);
MainWindow& operator= (const MainWindow&);
bool construct(); //二阶构造模式
bool initMenuBar(); //初始化菜单栏
bool initToolBar(); //初始化工具栏
bool initStatusBar(); //初始化状态栏
bool initMainEditor();//初始化文本编辑组件
//菜单设置
bool initFileMenu(QMenuBar* mb); //“文件”菜单
bool initEditMenu(QMenuBar* mb); //“编辑”菜单
bool initFormatMenu(QMenuBar* mb); //“格式”菜单
bool initViewMenu(QMenuBar* mb); //“查看”菜单
bool initHelpMenu(QMenuBar* mb); //“帮助”菜单
//工具栏设置
bool initFileToolItem(QToolBar* tb);
bool initEditToolItem(QToolBar* tb);
bool initFormatToolItem(QToolBar* tb);
bool initViewToolItem(QToolBar* tb);
//生成菜单项
bool makeAction(QAction*& action, QWidget* parent, QString text, int key);
//生成工具栏中的各按钮
bool makeAction(QAction*& action, QWidget* parent, QString tip, QString icon);
QString showFileDialog(QFileDialog::AcceptMode mode, QString title);//显示打开和保存对话框
void showErrorMessage(QString message);//显示“错误对话框”(QMessagBox)
int showQueryMessage(QString message); //显示“询问对话框”
QString saveCurrentData(QString path = "", QString title = "Save"); //保存编辑框中的内容
void preEditorChanged(); //判断文本框是否被更改，并决定是否弹出“保存对话框”
void openFileToEditor(QString path);
QAction* findMenuBarAction(QString text);
QAction* findToolBarAction(QString text);
protected:
void closeEvent(QCloseEvent *e); //重写窗体的关闭事件
void dragEnterEvent(QDragEnterEvent* e);
void dropEvent(QDropEvent * e);
private slots:
void onFileNew();
void onFileOpen();
void onFileSave();
void onFileSaveAs();
void onFilePrint();
void onFileExit();
void onTextChanged();//文本框内容发生改变里，会收到textChanged信号，这里是接收该信号的槽函数
void onCopyAvailable(bool available);
void onRedoAvailable(bool available);
void onUndoAvailable(bool available);
void onCursorPositionChanged();
void onEditDelete();
void onEditFind();
void onEditReplace();
void onEditGoto();
void onFormatFont();
void onFormatWrap();
void onViewToolBar();
void onViewStatusBar();
void onHelpAbout();
void onHelpManual();
public:
static MainWindow* NewInstance();
~MainWindow();
};
#endif // MAINWINDOW_H
//MainWindowUI.cpp
#include "MainWindow.h"
#include <QMenu>
#include <QToolBar>
#include <QStatusBar>
#include <QLabel>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent),
m_pFindDlg(new FindDialog(this,&mainEditor)),
m_pRelaceDlg(new ReplaceDialog(this, &mainEditor))
{
setWindowTitle("NotePad - [ New ]");
mainEditor.setAcceptDrops(false);//默认下，QPlainTextEdit是接收拖放事件的
//其父对象会收不到“拖放”事件，这里设为false
setAcceptDrops(true); //由MainWindow来接管拖放事件
m_filePath = "";
m_isTextChanged = false;
}
//二阶构造中的第2阶构造
bool MainWindow::construct()
{
bool ret = true;
ret = ret && initMenuBar();
ret = ret && initToolBar();
ret = ret && initStatusBar();
ret = ret && initMainEditor();
return ret;
}
MainWindow* MainWindow::NewInstance()
{
MainWindow* ret = new MainWindow();
if((ret == NULL) || !ret->construct())
{
delete ret;
ret = NULL;
}
return ret;
}
//初始化菜单栏
bool MainWindow::initMenuBar()
{
bool ret = true;
QMenuBar* mb = menuBar(); //menuBar为QMainWindow的成员变量
ret = ret && initFileMenu(mb);
ret = ret && initEditMenu(mb);
ret = ret && initFormatMenu(mb);
ret = ret && initViewMenu(mb);
ret = ret && initHelpMenu(mb);
return ret;
}
//初始化工具栏
bool MainWindow::initToolBar()
{
bool ret = true;
QToolBar* tb = addToolBar("Tool Bar");
tb->setIconSize(QSize(, ));
ret = ret && initFileToolItem(tb);
tb->addSeparator();
ret = ret && initEditToolItem(tb);
tb->addSeparator();
ret = ret && initFormatToolItem(tb);
tb->addSeparator();
ret = ret && initViewToolItem(tb);
return ret;
}
//初始化状态栏
bool MainWindow::initStatusBar()
{
bool ret = true;
QStatusBar* sb = statusBar();
QLabel* label = new QLabel("D.T.Software");
if( label != NULL )
{
statusLbl.setMinimumWidth();
statusLbl.setAlignment(Qt::AlignCenter);
statusLbl.setText("Ln: 1 Col: 1");
label->setMinimumWidth();
label->setAlignment(Qt::AlignCenter);
sb->addPermanentWidget(new QLabel()); //添加分隔线
sb->addPermanentWidget(&statusLbl);
sb->addPermanentWidget(label);
}
else
{
ret = false;
}
return ret;
}
//初始化主文本编辑组件
bool MainWindow::initMainEditor()
{
bool ret = true;
QPalette p = mainEditor.palette();
p.setColor(QPalette::Inactive, QPalette::Highlight,
p.color(QPalette::Active, QPalette::Highlight));
p.setColor(QPalette::Inactive, QPalette::HighlightedText,
p.color(QPalette::Active, QPalette::HighlightedText));
mainEditor.setPalette(p);
mainEditor.setParent(this);
connect(&mainEditor, SIGNAL(textChanged()), this, SLOT(onTextChanged()));
connect(&mainEditor, SIGNAL(copyAvailable(bool)),this,SLOT(onCopyAvailable(bool)));
connect(&mainEditor, SIGNAL(redoAvailable(bool)),this,SLOT(onRedoAvailable(bool)));
connect(&mainEditor, SIGNAL(undoAvailable(bool)),this,SLOT(onUndoAvailable(bool)));
connect(&mainEditor, SIGNAL(cursorPositionChanged()), this, SLOT(onCursorPositionChanged()));
setCentralWidget(&mainEditor);
return ret;
}
//文件(下拉)菜单
bool MainWindow::initFileMenu(QMenuBar* mb)
{
QMenu* menu = new QMenu("File(&F)", mb);//指定parent为mb
bool ret = (menu != NULL);
if ( ret )
{
QAction* action = NULL;
//"新建"菜单项
ret = ret && makeAction(action, mb, "New(&N)", Qt::CTRL + Qt::Key_N);
if(ret)
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileNew()));
menu->addAction(action); //add Action to Menu Item
}
//"打开"菜单项
ret = ret && makeAction(action, mb, "Open(&O)...", Qt::CTRL + Qt::Key_O);
if(ret)
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileOpen()));
menu->addAction(action); //add Action to Menu Item
}
//"保存"菜单项
ret = ret && makeAction(action, mb, "Save(&S)", Qt::CTRL + Qt::Key_S);
if(ret)
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileSave()));
menu->addAction(action); //add Action to Menu Item
}
//"另存为"菜单项
ret = ret && makeAction(action, mb, );
if(ret)
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileSaveAs()));
menu->addAction(action); //add Action to Menu Item
}
//水平分隔线
menu->addSeparator();
//"打印"菜单项
ret = ret && makeAction(action, mb, "Print(&P)...", Qt::CTRL + Qt::Key_P);
if(ret)
{
connect(action, SIGNAL(triggered()),this, SLOT(onFilePrint()));
menu->addAction(action); //add Action to Menu Item
}
menu->addSeparator();
//"退出"菜单项
ret = ret && makeAction(action, mb, "Exit(&X)", Qt::CTRL + Qt::Key_Q);
if(ret)
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileExit()));
menu->addAction(action); //add Action Item to Menu
}
}
if ( ret )
{
mb->addMenu(menu); //add Menu to Menu Bar
}
else
{
delete menu;
}
return ret;
}
//“编辑”菜单
bool MainWindow::initEditMenu(QMenuBar* mb)
{
QMenu* menu = new QMenu("Edit(&E)", mb);
bool ret = (menu != NULL);
if( ret )
{
QAction* action = NULL;
ret = ret && makeAction(action, mb, "Undo(&U)", Qt::CTRL + Qt::Key_Z);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(undo()));
action->setEnabled(false);
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Redo(&R)...", Qt::CTRL + Qt::Key_Y);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(redo()));
action->setEnabled(false);
menu->addAction(action);
}
menu->addSeparator();
ret = ret && makeAction(action, mb, "Cut(&T)", Qt::CTRL + Qt::Key_X);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(cut()));
action->setEnabled(false);
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Copy(&C)", Qt::CTRL + Qt::Key_C);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(copy()));
action->setEnabled(false);
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Paste(&P)", Qt::CTRL + Qt::Key_V);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(paste()));
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Delete(&L)", Qt::Key_Delete);
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditDelete()));
menu->addAction(action);
}
menu->addSeparator();
ret = ret && makeAction(action, mb, "Find(&F)...", Qt::CTRL + Qt::Key_F);
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditFind()));
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Replace(&R)...", Qt::CTRL + Qt::Key_H);
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditReplace()));
menu->addAction(action);
}
ret = ret && makeAction(action, mb, "Goto(&G)...", Qt::CTRL + Qt::Key_G);
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditGoto()));
menu->addAction(action);
}
menu->addSeparator();
ret = ret && makeAction(action, mb, "Select All(&A)...", Qt::CTRL + Qt::Key_A);
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(selectAll()));
menu->addAction(action);
}
}
if ( ret )
{
mb->addMenu(menu);
}
else
{
delete menu;
}
return ret;
}
//“格式”菜单
bool MainWindow::initFormatMenu(QMenuBar* mb)
{
QMenu* menu = new QMenu("Format(&O)", mb);
bool ret = ( menu != NULL);
if (ret)
{
QAction* action = NULL;
ret = ret && makeAction(action, mb, );
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onFormatWrap()));
menu ->addAction(action);
}
ret = ret && makeAction(action, mb, );
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFormatFont()));
menu ->addAction(action);
}
}
if ( ret )
{
mb->addMenu(menu);
}
else
{
delete menu;
}
return ret;
}
//“查看”菜单
bool MainWindow::initViewMenu(QMenuBar* mb)
{
QMenu* menu = new QMenu("View(&V)", mb);
bool ret = ( menu != NULL);
if (ret)
{
QAction* action = NULL;
ret = ret && makeAction(action, mb, );
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onViewToolBar()));
menu ->addAction(action);
}
ret = ret && makeAction(action, mb, );
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onViewStatusBar()));
menu ->addAction(action);
}
}
if ( ret )
{
mb->addMenu(menu);
}
else
{
delete menu;
}
return ret;
}
//“帮助”菜单
bool MainWindow::initHelpMenu(QMenuBar* mb)
{
QMenu* menu = new QMenu("Help(&H)", mb);
bool ret = ( menu != NULL);
if (ret)
{
QAction* action = NULL;
ret = ret && makeAction(action, mb, );
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onHelpManual()));
menu ->addAction(action);
}
ret = ret && makeAction(action, mb, );
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onHelpAbout()));
menu ->addAction(action);
}
}
if ( ret )
{
mb->addMenu(menu);
}
else
{
delete menu;
}
return ret;
}
//工具栏设置
bool MainWindow::initFileToolItem(QToolBar* tb)
{
bool ret = true;
QAction* action = NULL;
ret = ret && makeAction(action, tb, "New", ":/Res/pic/new.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileNew()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Open", ":/Res/pic/open.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileOpen()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Save", ":/Res/pic/save.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileSave()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Save As", ":/Res/pic/saveas.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFileSaveAs()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Print", ":/Res/pic/print.png");
if ( ret )
{
connect(action, SIGNAL(triggered()),this, SLOT(onFilePrint()));
tb->addAction(action);
}
return ret;
}
bool MainWindow::initEditToolItem(QToolBar* tb)
{
bool ret = true;
QAction* action = NULL;
ret = ret && makeAction(action, tb, "Undo", ":/Res/pic/undo.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(undo()));
action->setEnabled(false);
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Redo", ":/Res/pic/redo.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(redo()));
action->setEnabled(false);
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Cut", ":/Res/pic/cut.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(cut()));
action->setEnabled(false);
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Copy", ":/Res/pic/copy.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(copy()));
action->setEnabled(false);
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Paste", ":/Res/pic/paste.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), &mainEditor, SLOT(paste()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Find", ":/Res/pic/find.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditFind()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Replace", ":/Res/pic/replace.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onEditReplace()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Goto", ":/Res/pic/goto.png");
if ( ret )
{
tb->addAction(action);
}
return ret;
}
bool MainWindow::initFormatToolItem(QToolBar* tb)
{
bool ret = true;
QAction* action = NULL;
ret = ret && makeAction(action, tb, "Auto Wrap", ":/Res/pic/wrap.png");
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onFormatWrap()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Font", ":/Res/pic/font.png");
if ( ret )
{
connect(action, SIGNAL(triggered()), this, SLOT(onFormatFont()));
tb->addAction(action);
}
return ret;
}
bool MainWindow::initViewToolItem(QToolBar* tb)
{
bool ret = true;
QAction* action = NULL;
ret = ret && makeAction(action, tb, "Tool Bar", ":/Res/pic/tool.png");
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onViewToolBar()));
tb->addAction(action);
}
ret = ret && makeAction(action, tb, "Status Bar", ":/Res/pic/status.png");
if ( ret )
{
action->setCheckable(true);
action->setChecked(true);
connect(action, SIGNAL(triggered()), this, SLOT(onViewStatusBar()));
tb->addAction(action);
}
return ret;
}
//生成菜单项（第1个参数是菜单项对象，第2个参数为父组件，第3个参数为显示文本，第4个参数为快捷键）
bool MainWindow::makeAction(QAction*& action, QWidget* parent, QString text, int key)
{
bool ret = true;
action = new QAction(text, parent); //设置parent
if(action != NULL)
{
action->setShortcut(QKeySequence(key)); //设置快捷键
}
else
{
ret = false;
}
return ret;
}
//生成工具栏中的各按钮
bool MainWindow::makeAction(QAction*& action, QWidget* parent, QString tip, QString icon)
{
bool ret = true;
action = new QAction("", parent);
if( action != NULL )
{
action ->setToolTip(tip);
action->setIcon(QIcon(icon));
}
else
{
ret = false;
}
return ret;
}
MainWindow::~MainWindow()
{
}
//MainWindowSlots.cpp
//该文件MainWindowSlots.cpp与MainWindowUI.cpp的分离
//体现了界面和功能代码分离的思想
#include "MainWindow.h"
#include "AboutDialog.h"
#include <QMessageBox>
#include <QFile>
#include <QTextStream>
#include <QMap>
#include <QCloseEvent>
#include <QDragEnterEvent>
#include <QDropEvent>
#include <QMimeData>
#include <QToolBar>
#include <QPrintDialog> //QT += printsupport
#include <QApplication>
#include <QInputDialog>
#include <QStatusBar>
#include <QFontDialog>
#include <QDesktopServices>
#include <QDebug>
void MainWindow::showErrorMessage(QString message)
{
QMessageBox msg(this);
msg.setWindowTitle("Erro");
msg.setText(message);
msg.setIcon(QMessageBox::Critical);
msg.setStandardButtons(QMessageBox::Ok);
msg.exec();
}
int MainWindow::showQueryMessage(QString message)
{
QMessageBox msg(this);
msg.setWindowTitle("Query");
msg.setText(message);
msg.setIcon(QMessageBox::Question);
msg.setStandardButtons(QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel);
return msg.exec();
}
QString MainWindow::showFileDialog(QFileDialog::AcceptMode mode, QString title)
{
QString ret = "";
QFileDialog fd(this);
QStringList filters;
QMap<QString, QString> map;
] =
{
{"Text(*.txt)", ".txt"},
{"All Files(*.*)", "*" },
{NULL, NULL}
};
; filterArray[i][] != NULL; i++)
{
filters.append(filterArray[i][]);
map.insert(filterArray[i][], filterArray[i][]);
}
fd.setWindowTitle(title);
fd.setAcceptMode(mode); //QFileDialog::AcceptOpen或AcceptSave
fd.setNameFilters(filters);
if(mode == QFileDialog::AcceptOpen)
{
fd.setFileMode(QFileDialog::ExistingFile); //打开文件必须存在！
}
if(fd.exec() == QFileDialog::Accepted)
{
ret = fd.selectedFiles()[];
//Qt5中ret返回的是完整的路径名，含后缀。因此，后面的if块可省略，但Qt4可能
//会返回不带后缀的文件名，当保存文件时，须手动加上去。
if(mode == QFileDialog::AcceptSave)
{
QString postfix = map[fd.selectedNameFilter()];
if((postfix != "*") && !ret.endsWith(postfix))
{
ret = ret + postfix;
}
}
}
return ret;
}
void MainWindow::preEditorChanged()
{
if (m_isTextChanged)
{
int r = showQueryMessage("Do you want to save the changes to file?");
switch(r)
{
case QMessageBox::Yes:
saveCurrentData(m_filePath);
break;
case QMessageBox::No:
m_isTextChanged = false;
break;
case QMessageBox::Cancel:
break;
}
}
}
void MainWindow::onFileNew()
{
preEditorChanged();
if(!m_isTextChanged)
{
mainEditor.clear();
setWindowTitle("NotePad - [ New ]");
m_filePath = "";
m_isTextChanged = false;
}
}
void MainWindow::openFileToEditor(QString path)
{
if( path != "")
{
QFile file(path);
if (file.open(QIODevice::ReadOnly | QIODevice::Text))
{
mainEditor.setPlainText(QString(file.readAll()));
file.close();
m_filePath = path; //记录当前打开的文件路径和文件名
m_isTextChanged = false;
setWindowTitle("NotePad - [" + m_filePath + "]");
}
else
{
showErrorMessage(QString("Open file Error!\n\n") + "\"" + path + "\"");
}
}
}
void MainWindow::onFileOpen()
{
preEditorChanged();
if( !m_isTextChanged)
{
QString path = showFileDialog(QFileDialog::AcceptOpen, "Open");
openFileToEditor(path);
}
}
QString MainWindow::saveCurrentData(QString path, QString title)
{
QString ret = path;
if (ret =="")
{
//执行下面语句时，用户可以点击“取消”，此时ret返回""
ret = showFileDialog(QFileDialog::AcceptSave, title);
}
if (ret != "")
{
QFile file(ret);
if (file.open(QIODevice::WriteOnly | QIODevice::Text))
{
QTextStream out(&file);
out << mainEditor.toPlainText();
file.close();
setWindowTitle("NotePad - [" + ret + "]");
m_isTextChanged = false; //己保存
}
else
{
showErrorMessage(QString("Save file Error!\n\n") + "\"" + m_filePath + "\"");
ret =""; //保存失败时
}
}
return ret;
}
void MainWindow::onFileSave()
{
QString path = saveCurrentData(m_filePath, "Save");
if( path != "" )
{
m_filePath = path;
}
}
void MainWindow::onFileSaveAs()
{
QString path = saveCurrentData(m_filePath, "Save As");
if( path != "" )
{
m_filePath = path;
}
}
void MainWindow::onTextChanged()
{
if( !m_isTextChanged )
{
setWindowTitle("*" + windowTitle());
}
m_isTextChanged = true;
//qDebug()<< "onTextChanged()";
}
void MainWindow::closeEvent(QCloseEvent* e)
{
preEditorChanged();
if(!m_isTextChanged)
{
QMainWindow::closeEvent(e);
}
else
{
//当用户按下“取消”
e->ignore();//忽略关闭事件
}
}
void MainWindow::dragEnterEvent(QDragEnterEvent *e)
{
if(e->mimeData()->hasUrls())
{
e->acceptProposedAction();
}
else
{
e->ignore();
}
}
void MainWindow::dropEvent(QDropEvent *e)
{
qDebug() << "dropEvent";
if(e->mimeData()->hasUrls())
{
QList<QUrl> list = e->mimeData()->urls();
QString path = list[].toLocalFile();
QFileInfo fi(path);
if(fi.isFile())
{
preEditorChanged();
if(!m_isTextChanged)
{
openFileToEditor(path);
}
}
else
{
showErrorMessage("Can't open a folder!");
}
}
else
{
e->ignore();
}
}
void MainWindow::onCopyAvailable(bool available)
{
QAction* action = findMenuBarAction("Copy");
if (action != NULL) action->setEnabled(available);
action = findMenuBarAction("Cut");
if (action != NULL) action->setEnabled(available);
action = findToolBarAction("Copy");
if (action != NULL) action->setEnabled(available);
action = findToolBarAction("Cut");
if (action != NULL) action->setEnabled(available);
}
void MainWindow::onRedoAvailable(bool available)
{
QAction* action = findMenuBarAction("Redo");
if (action != NULL) action->setEnabled(available);
action = findToolBarAction("Redo");
if (action != NULL) action->setEnabled(available);
}
void MainWindow::onUndoAvailable(bool available)
{
QAction* action = findMenuBarAction("Undo");
if (action != NULL) action->setEnabled(available);
action = findToolBarAction("Undo");
if (action != NULL) action->setEnabled(available);
}
QAction* MainWindow::findMenuBarAction(QString text)
{
QAction* ret = NULL;
const QObjectList& list = menuBar()->children();
; i<list.count(); i++)
{
//各菜单（如文件、编辑、查看等）
QMenu* menu = dynamic_cast<QMenu*>(list[i]);
if(menu != NULL)
{
QList<QAction*> actions = menu->actions();
; j<actions.count(); j++)
{
if(actions[j]->text().startsWith(text))
{
ret = actions[j];
break;
}
}
}
}
return ret;
}
QAction* MainWindow::findToolBarAction(QString text)
{
QAction* ret = NULL;
const QObjectList& list = children();
; i<list.count(); i++)
{
QToolBar* toolBar = dynamic_cast<QToolBar*>(list[i]);
if(toolBar != NULL)
{
QList<QAction*> actions = toolBar->actions();
; j<actions.count(); j++)
{
if(actions[j]->toolTip().startsWith(text))
{
ret = actions[j];
break;
}
}
}
}
return ret;
}
void MainWindow::onFilePrint()
{
QPrintDialog dlg(this);
dlg.setWindowTitle("Print");
if(dlg.exec() == QPrintDialog::Accepted)
{
QPrinter* p = dlg.printer();
mainEditor.document()->print(reinterpret_cast<QPagedPaintDevice*>(p));
}
}
void MainWindow::onCursorPositionChanged()
{
int pos = mainEditor.textCursor().position();
QString text = mainEditor.toPlainText();
;//列数
; //行数
; //用于记录光标之前最后一个'\n'所在索引位置
//从头到光标所在位置
; i<pos; i++)
{
if( text[i] == '\n')
{
ln++;
flag = i;
}
}
col = pos -(flag + );
statusLbl.setText() + ));
}
void MainWindow::onEditDelete()
{
QKeyEvent keyPress(QEvent::KeyPress, Qt::Key_Delete, Qt::NoModifier);
QKeyEvent keyRelease(QEvent::KeyRelease, Qt::Key_Delete, Qt::NoModifier);
QApplication::sendEvent(&mainEditor, &keyPress);
QApplication::sendEvent(&mainEditor, &keyRelease);
}
void MainWindow::onEditFind()
{
m_pFindDlg->show();
}
void MainWindow::onEditReplace()
{
m_pRelaceDlg->show();
}
void MainWindow::onEditGoto()
{
bool ok = false;
,,mainEditor.document()->lineCount(),
,&ok,Qt::WindowCloseButtonHint | Qt::Drawer);
if (ok)
{
QString text = mainEditor.toPlainText();
QTextCursor c = mainEditor.textCursor();
;
;//表示下一个换行符的位置
; i<ln; i++)
{
pos = next + ;
next = text.indexOf('\n', pos);
}
c.setPosition(pos);
mainEditor.setTextCursor(c);
}
}
void MainWindow::onViewToolBar()
{
//枚举窗体上的所有组件（含菜单、Editor、工具栏、状态栏等）
const QObjectList& list = children();
; i<list.count(); i++)
{
QToolBar* tb = dynamic_cast<QToolBar*>(list[i]);
if(tb != NULL)
{
bool visible = tb->isVisible();
tb->setVisible(!visible);
//更新菜单栏和工具栏的状态标志
findMenuBarAction("Tool Bar")->setChecked(!visible);
findToolBarAction("Tool Bar")->setChecked(!visible);
break;
}
}
}
void MainWindow::onViewStatusBar()
{
QStatusBar* sb = statusBar();
bool visible = sb->isVisible();
sb->setVisible(!visible);
//更新菜单栏和工具栏的状态标志
findMenuBarAction("Status Bar")->setChecked(!visible);
findToolBarAction("Status Bar")->setChecked(!visible);
}
void MainWindow::onFileExit()
{
close();
}
void MainWindow::onFormatWrap()
{
QPlainTextEdit::LineWrapMode mode = mainEditor.lineWrapMode();
if(mode == QPlainTextEdit::NoWrap)
{
mainEditor.setLineWrapMode(QPlainTextEdit::WidgetWidth);
findMenuBarAction("Auto Wrap")->setChecked(true);
findToolBarAction("Auto Wrap")->setChecked(true);
}
else
{
mainEditor.setLineWrapMode(QPlainTextEdit::NoWrap);
findMenuBarAction("Auto Wrap")->setChecked(false);
findToolBarAction("Auto Wrap")->setChecked(false);
}
}
void MainWindow::onFormatFont()
{
bool ok = false;
QFont font = QFontDialog::getFont(&ok, mainEditor.font(), this);
if(ok)
{
mainEditor.setFont(font);
}
}
void MainWindow::onHelpManual()
{
//打开本地文件
QDesktopServices::openUrl(QUrl("file:///C:/Users/santaclaus/Desktop/help.txt"));
//打开网站
//QDesktopServices::openUrl(QUrl("http://www.xxx.com"));
}
void MainWindow::onHelpAbout()
{
AboutDialog(this).exec();
}
4. 小结
（1）关于对话框用于标识软件自身的信息
（2）使用QFontDialog设置文本编辑框的字体
（3）设置文本编辑框的自动换行属性
（4）通过QDesktopServices使用桌面环境的系统服务
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