這是第9篇學(xué)習(xí)QT的例子
本文主要學(xué)習(xí)自帶的Dock Widget例子
這個例子主要包含以下QT控件
1.Dock
2.Menu
3.ToolBar
1.看看例子還是說
QMainWindow吧
什么是QMainWindow?
A main window provides a framework for building an application's user interface. Qt has QMainWindow and its related classes for main window management. QMainWindow has its own layout to which you can add QToolBars, QDockWidgets, QDockBars,QDockWidgets, a QStatusBar. 總而言之:QMainWindow提供構(gòu)建應(yīng)用程序接口的框架。QMainWindow提供獨有的布局結(jié)構(gòu)以便于用戶加入QToolBar,QDockWidgets,QDockBars和QStatusBar.
2.使用自定義對象從QT對象繼承的方法
除了必要的 :public QTObject
還要加入宏Q_OBJECT
如果必要加入槽,信號函數(shù)
一個例子是:
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow();
private slots:
void newLetter();
void save();
void print();
void undo();
void about();
void insertCustomer(const QString &customer);
void addParagraph(const QString ¶graph);
3.狀態(tài)欄
設(shè)置狀態(tài)欄信息的函數(shù)
例子:
statusBar()->showMessage(tr("Ready"));
4.文件打開和保存對話框
QString fileName = QFileDialog::getSaveFileName(this,
tr("Choose a file name"), ".",
tr("HTML (*.html *.htm)"));
5.再說下QAction
newLetterAct = new QAction(QIcon(":/images/new.png"), tr("&New Letter"),
this);
newLetterAct->setShortcuts(QKeySequence::New);
newLetterAct->setStatusTip(tr("Create a new form letter"));
connect(newLetterAct, SIGNAL(triggered()), this, SLOT(newLetter()));
通過調(diào)用setStatusTip可以設(shè)置action提示信息
6.
QTextDocument對象
原文解釋:
The QTextDocument class holds formatted text that can be viewed and edited using a QTextEdit.
通過QTextEdit的document可以獲取QTextDocument對象
假定需要響應(yīng)文檔撤銷事件
一個可能的例子就是:
void MainWindow::undo()
{
QTextDocument *document = textEdit->document();
document->undo();
}
7.QTextCursor
The QTextCursor class offers an API to accDuess and modify QTextDocuments.
我們就可以得出QTextCursor訪問和修改QTextDocument,QTextDocumnt顯示QTextEdit內(nèi)容文本。
8.QDockWidget
The QDockWidget class provides a widget that can be docked inside a QMainWindow floated as a top-level window on the desktop.關(guān)于Dock的用法如下:
設(shè)置Dock為左右結(jié)構(gòu)
dock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
設(shè)置Dock內(nèi)容控件
dock
->setWidget
(customerList
);
把這個dock放在窗體右邊
addDockWidget
(Qt::RightDockWidgetArea
, dock
);
9.這個例子還有其他的對象比如QListWidget以后再看吧
不過這一篇感覺有幾個疑惑的地方
比如:
QDockWidget *dock = new QDockWidget(tr("Customers"), this);
dock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
customerList = new QListWidget(dock);
customerList->addItems(QStringList()
<< "John Doe, Harmony Enterprises, 12 Lakeside, Ambleton"
<< "Jane Doe, Memorabilia, 23 Watersedge, Beaton"
<< "Tammy Shea, Tiblanka, 38 Sea Views, Carlton"
<< "Tim Sheen, Caraba Gifts, 48 Ocean Way, Deal"
<< "Sol Harvey, Chicos Coffee, 53 New Springs, Eccleston"
<< "Sally Hobart, Tiroli Tea, 67 Long River, Fedula");
dock->setWidget(customerList);
addDockWidget(Qt::RightDockWidgetArea, dock);
viewMenu->addAction(dock->toggleViewAction());
dock = new QDockWidget(tr("Paragraphs"), this);
其中的dock new了2次并沒有調(diào)用相應(yīng)的delete.
不知道QT具體是如何實現(xiàn)的
另外在QT的例子中在程序結(jié)束的時候并沒有銷毀new出來的指針
不知道QT有內(nèi)在機制保證內(nèi)存不會泄露還是?