从extenionplugin的C++ 模块中读取数据并显示到Qt的ListView上

这次加载的数据来自于C++动态库而不是另一个qml文件。这个比之前的文章复杂。

我的项目目录树如下：

/listview2$ tree
.
├── imports
│   └── mylist
│       ├── libmylist.so
│       └── qmldir
├── list2.pro
├── plugin.cpp
├── run.sh
└── test.qml

The list2.pro文件内容如下：

TEMPLATE = lib
CONFIG += plugin
QT += qml
DESTDIR = imports/mylist
TARGET  = mylist
SOURCES += plugin.cpp
qml.files = test.qml
qml.path += ./
pluginfiles.files += imports/mylist/qmldir
pluginfiles.path += imports/mylist
target.path += imports/mylist
INSTALLS += target qml pluginfiles

模块目录下的qmldir做了修改：

module mylist
plugin mylist

为了方便，我在一个plugin.cpp文件中实现了所有的C++代码。

#include <QtQml/QQmlExtensionPlugin>
#include <QtQml/qqml.h>
#include <qdebug.h>
#include <qdatetime.h>
#include <qbasictimer.h>
#include <qcoreapplication.h>
#include <QAbstractItemModel>
#include <QStringList>
class People {
public:
  People(QString const & name, QString const & number)
    : name_(name), number_(number) {
  }
  QString name() const {
    return name_;
  }
  QString number() const {
    return number_;
  }
private:
  QString name_;
  QString number_;
};
class PeopleListModel : public QAbstractListModel {
  Q_OBJECT
public:
  enum PeopleRoles {
    NameRole = Qt::UserRole + 1,
    NumberRole
  };
  PeopleListModel(QObject * parent = 0)
    : QAbstractListModel(parent) {
    People p1("Dean", "186***");
    addPeople(p1);
    People p2("Crystal", "186***");
    addPeople(p2);
  }
  void addPeople(People const & p) {
    beginInsertRows(QModelIndex(), rowCount(), rowCount());
    values_ << p;
    endInsertRows();
  }
  int rowCount(QModelIndex const & parent = QModelIndex()) const {
    return values_.count();
  }
  QVariant data(QModelIndex const & index, int role = Qt::DisplayRole) const {
    if (index.row() < 0 || index.row() >= values_.count())
      return QVariant();
    People const & p = values_[index.row()];
    if (role == NameRole)
      return p.name();
    else if (role == NumberRole)
      return p.number();
    return QVariant();
  }
protected:
  QHash<int, QByteArray> roleNames() const {
    QHash<int, QByteArray> roles;
    roles[NameRole] = "name";
    roles[NumberRole] = "number";
    return roles;
  }
private:
  QList<People> values_;
};
class QExampleQmlPlugin : public QQmlExtensionPlugin {
  Q_OBJECT
  Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QQmlExtension.PeopleListModel")
  public:
  void registerTypes(char const * uri) {
    qmlRegisterType<PeopleListModel>(uri, 1, 0, "PeopleListModel");
  }
};
#include "plugin.moc"

People类很简单，只包含了两个属性: name和number

PeopleListModel类继承自QAbstractListModel, 它提供了ListView需要的数据。

QExampleQmlPlugin类是plugin类，注册了PeopleListModel类。

注意PeopleListModel类的三个方法：rowCount, data和roleNames. 它们都是ListView需要的。

要想理解Model-View体系结构，请从下面的文档开始。

http://doc-snapshot.qt-project.org/qdoc/model-view-programming.html#introduction-to-model-view-programming