QT_FORWARD_DECLARE_CLASS 相当于class 类名。 那么他和#include 包含头文件有什么区别呢 首先 我们为什么要包括头文件 问题的回答很简单 通常是我们需要获得某个 类型的定义(definition)。那么接下来的问题就是 在什么情况下我们才需要类 型的定义 在什么情况下我们只需要声明就足够了 问题的回答是当我们需要知 ...
class ConnectionWidget; QT_FORWARD_DECLARE_CLASS(QTableView) QT_FORWARD_DECLARE_CLASS(QPushButton) QT_FORWARD_DECLARE_CLASS(QTextEdit) QT_FORWARD_DECLARE_CLASS(QSqlError) class Browser: public QWidget, private Ui::Browser { Q_OBJECT public: Browser(QWidget *parent = nullptr); virtual ~Browser(...
完整头文件如下: #ifndefASYNCHASHER_H#defineASYNCHASHER_H#include<QCryptographicHash>#include<QFuture>#include<QObject>#include<QUrl>QT_FORWARD_DECLARE_CLASS(QNetworkAccessManager); QT_FORWARD_DECLARE_CLASS(AsyncHasherPrivate);classAsyncHasher:public QObject { Q_OBJECTQ_PROPERTY(QCryptographicHash::Algorit...
QT_FORWARD_DECLARE_CLASS(QBluetoothServiceInfo) //发现过程依赖于蓝牙服务发现过程 (SDP)。 //查询所有可接触蓝牙设备提供的服务需要以下步骤: //创建一个 QBluetoothServiceDiscoveryAgent 实例, //连接到 serviceDiscovered() 或 finished() 信号, //并调用 start()。 QT_FORWARD_DECLARE_CLASS(QBluetoothServic...
#include "spotifyapi.h"QT_FORWARD_DECLARE_CLASS(QNetworkReply)class SpotifyModel : public QAbstractListModel { Q_OBJECT QML_ELEMENTQ_PROPERTY(SpotifyAPI* spotifyApi READ spotifyApi WRITE setSpotifyApi NOTIFY spotifyApiChanged)public: SpotifyModel(QObject *parent = nullptr);...
#ifndefASYNCHASHER_H#defineASYNCHASHER_H#include<QCryptographicHash>#include<QFuture>#include<QObject>#include<QUrl>QT_FORWARD_DECLARE_CLASS(QNetworkAccessManager);QT_FORWARD_DECLARE_CLASS(AsyncHasherPrivate);class AsyncHasher:public QObject{Q_OBJECTQ_PROPERTY(QCryptographicHash::Algorithm algorithm READ al...
QT_FORWARD_DECLARE_CLASS(QTimer) class RandomListModel : public QAbstractListModel { Q_OBJECT public: RandomListModel(QObject *parent = nullptr); ~RandomListModel(); int rowCount(const QModelIndex & = QModelIndex()) const override; QVariant data(const QModelIndex &, int) const override; ...
QT_BEGIN_NAMESPACE class name; QT_END_NAMESPACE / using QT_PREPEND_NAMESPACE(name); # define QT_FORWARD_DECLARE_STRUCT(name) / QT_BEGIN_NAMESPACE struct name; QT_END_NAMESPACE / using QT_PREPEND_NAMESPACE(name); Q_GLOBAL_STATIC(type, name)用于定义一个全局的静态变量(线程安全的).用它...
QT_BEGIN_NAMESPACE class name; QT_END_NAMESPACE / using QT_PREPEND_NAMESPACE(name); # define QT_FORWARD_DECLARE_STRUCT(name) / QT_BEGIN_NAMESPACE struct name; QT_END_NAMESPACE / using QT_PREPEND_NAMESPACE(name); Q_GLOBAL_STATIC(type, name)用于定义一个全局的静态变量(线程安全的).用它...
QT_FORWARD_DECLARE_CLASS(QTextCharFormat) QT_FORWARD_DECLARE_CLASS(QMenu) class TextEdit : public QMainWindow { Q_OBJECT public: TextEdit(QWidget *parent = 0); protected: virtual void closeEvent(QCloseEvent *e); private: void setupFileActions(); void setupEditActions(); ...