这是第9篇学习QT的例子
本文主要学习自带的Dock Widget例子
这个例子主要包含以下QT控件
1.Dock
2.Menu
3.ToolBar
1.看看例子还是说
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. 总而言之:QMainWindow提供构建应用程序接口的框架。QMainWindow提供独有的布局结构以便于用户加入QToolBar,QDockWidgets,QDockBars和QStatusBar.
2.使用自定义对象从QT对象继承的方法
除了必要的 :public QTObject
还要加入宏Q_OBJECT
如果必要加入槽,信号函数
一个例子是:
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.状态栏
设置状态栏信息的函数
例子:
statusBar()->showMessage(tr("Ready"));
4.文件打开和保存对话框
QString fileName = QFileDialog::getSaveFileName(this,
tr("Choose a file name"), ".",
tr("HTML (*.html *.htm)"));
5.再说下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()));
通过调用setStatusTip可以设置action提示信息
6.
QTextDocument对象
原文解释:
The QTextDocument class holds formatted text that can be viewed and edited using a QTextEdit.
通过QTextEdit的document可以获取QTextDocument对象
假定需要响应文档撤销事件
一个可能的例子就是:
void MainWindow::undo()
{
QTextDocument *document = textEdit->document();
document->undo();
}
7.QTextCursor
The QTextCursor class offers an API to accDuess and modify QTextDocuments.
我们就可以得出QTextCursor访问和修改QTextDocument,QTextDocumnt显示QTextEdit内容文本。
8.QDockWidget
The QDockWidget class provides a widget that can be docked inside a QMainWindow floated as a top-level window on the desktop.关于Dock的用法如下:
设置Dock为左右结构
dock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
设置Dock内容控件
dock
->setWidget
(customerList
);
把这个dock放在窗体右边
addDockWidget
(Qt::RightDockWidgetArea
, dock
);
9.这个例子还有其他的对象比如QListWidget以后再看吧
不过这一篇感觉有几个疑惑的地方
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次并没有调用相应的delete.
不知道QT具体是如何实现的
另外在QT的例子中在程序结束的时候并没有销毁new出来的指针
不知道QT有内在机制保证内存不会泄露还是?