将 Exposed 模型集成到 ListModel QML

Question

我已经成功地向我的 main.qml 公开了一个包含 3 个 C++ 整数的列表 在 main.qml 中使用 ListView

ListView {
width: 200; height: 250
required model
delegate: Text {
    required property int longitude
    required property int latitude
    required property int height_
    text: "Data: " + longitude + ", " + latitude +","+ height_
}}

我真正需要做的是将我的 C++ 模型集成到 ItemModelSurfaceDataProxy 中，像这样采用 ListModel

   ListModel {
            id: myModel
              ListElement{ longitude: "0"; latitude: "0"; height_: "124"; }   
    }}

main.qml 使用 qtdatavisualization-qmlsurface-example ,,example_source_code

Rectangle {
id: mainview
width: 1024
height: 768
color: surfacePlot.theme.windowColor

Item {
    id: surfaceView
    width: mainview.width
    height: mainview.height
    anchors.top: mainview.top
    anchors.left: mainview.left
    Surface3D {
        id: surfacePlot
        width: surfaceView.width
        height: surfaceView.height
        Surface3DSeries {
            id: surfaceSeries
            flatShadingEnabled: false
            drawMode: Surface3DSeries.DrawSurface

            ItemModelSurfaceDataProxy {
                itemModel: myModel **// this needs to be replaced by C++ model**
                rowRole: "longitude"
                columnRole: "latitude"
                yPosRole: "height_"
            }
            onDrawModeChanged: checkState()
        }
    }
    ListModel { **//This is the model that needs to be replaced by C++ Model**
            id: myModel
    }
  }}

main.cpp

   int main(int argc, char *argv[])
   {
    QGuiApplication app(argc, argv);
    AnimalModel model;
    model.addAnimal(Animal(1, 2,3));
    model.addAnimal(Animal(2,4,5));
    model.addAnimal(Animal(3,4,6));
    QQuickView viewer;
    viewer.setResizeMode(QQuickView::SizeRootObjectToView);
    viewer.setInitialProperties({{"model", QVariant::fromValue(&model)}});
    viewer.setSource(QUrl("qrc:/qml/qml/qmlsurface/main.qml"));
    viewer.setTitle(QStringLiteral("Egyptolict "));
    viewer.show();
    return app.exec();
   }

model.cpp 使用 QT example

#include "model.h"
Animal::Animal(const int &longitude, const int &latitude,const int &height_)
: m_longitude(longitude), m_latitude(latitude) ,m_height(height_){}

int Animal::longitude() const{
  return m_longitude;}
int Animal::latitude() const{
  return m_latitude;}
int Animal::height_() const{
  return m_height;}
AnimalModel::AnimalModel(QObject *parent)
: QAbstractListModel(parent)
{
 }
void AnimalModel::addAnimal(const Animal &animal)
{
beginInsertRows(QModelIndex(), rowCount(), rowCount());
m_animals << animal;
endInsertRows();
}
 int AnimalModel::rowCount(const QModelIndex & parent) const {
Q_UNUSED(parent);
return m_animals.count();
}
QVariant AnimalModel::data(const QModelIndex & index, int role) const {
if (index.row() < 0 || index.row() >= m_animals.count())
    return QVariant();

const Animal &animal = m_animals[index.row()];
if (role == longitudeRole)
    return animal.longitude();
else if (role == latitudeRole)
    return animal.latitude();
else if (role == heightRole)
    return animal.height_();
return QVariant();
}
QHash<int, QByteArray> AnimalModel::roleNames() const {
QHash<int, QByteArray> roles;
roles[longitudeRole] = "longitude";
roles[latitudeRole] = "latitude";
roles[heightRole] = "height_";
return roles;
}

model.h 使用 qt example

#include <QAbstractListModel>
#include <QStringList>
class Animal
{public:
Animal(const int &longitude, const int &latitude , const int &height_);
 int longitude() const;
 int latitude() const;
 int height_() const;
private:
 int m_longitude;
 int m_latitude;
 int m_height;
  };

 class AnimalModel : public QAbstractListModel
 {
  Q_OBJECT
 public:
  enum AnimalRoles {
    longitudeRole = Qt::UserRole + 1,
    latitudeRole,
    heightRole
   };

   AnimalModel(QObject *parent = 0);

  void addAnimal(const Animal &animal);
 int rowCount(const QModelIndex & parent = QModelIndex()) const;
 QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const;
 QHash<int, QByteArray> roleNames() const;
 private:
  QList<Animal> m_animals;
  };

Answer 1

你应该在rootContext上设置属性：

int main(int argc, char *argv[])
{
   QGuiApplication app(argc, argv);
   AnimalModel model;
   model.addAnimal(Animal(1, 2,3));
   model.addAnimal(Animal(2,4,5));
   model.addAnimal(Animal(3,4,6));
   
   QQuickView viewer;
   viewer.setResizeMode(QQuickView::SizeRootObjectToView);
   viewer.rootContext()->setContextProperty("model", &model);
   viewer.setSource(QUrl("qrc:/qml/qml/qmlsurface/main.qml"));
   viewer.setTitle(QStringLiteral("Egyptolict "));
   viewer.show();
   return app.exec();

}

setInitialProperties 函数尝试设置对象的属性（在本例中为“main.qml”文件），如果您将property var model 添加到“main.qml”，它可能会起作用。

PS，如果您不想混淆属性“高度”，您可以使用“高度”；-)

Answer 2

感谢@Amfasis 它通过在 rootContext 上设置属性来工作

viewer.rootContext()->setContextProperty("model", &model);

并在Item下添加了属性var模型

Item { 
      property var model
      ....
      }