我试图揭露QList
将自定义对象 ( Sample
) 导入到 QML 中。每当我将这些自定义对象(它们继承 QObject)存储到 QList<QObject *>
中时,它们出现了,但没有信息,但是当我尝试将它们公开为 QList<Sample *>
时,他们没有。
样本.h
class Sample : public QObject
{
Q_OBJECT
Q_PROPERTY(QString getVar READ getVar WRITE setVar NOTIFY varChanged)
public:
explicit Sample();
//! Returns var
QString getVar() const { return var; }
//! Sets var
void setVar(const QString &a);
signals:
varChanged();
protected:
QString var;
};
包含列表的类看起来像这样
samplecontrol.h
class SampleManager : public QObject
{
Q_OBJECT
Q_PROPERTY(QList<Sample *> getSampleList READ getSampleList NOTIFY sampleListChanged)
public:
SampleManager(const QString &path);
//! Returns sample list
QList<Sample *> getSampleList() const { return sampleList_; }
signals:
sampleListChanged();
protected:
QList<Sample *> sampleList_;
};
我正在设置上下文
view_->rootContext()->setContextProperty("slabGridModel", QVariant::fromValue(samplecontrol.getSampleList()));
正如我所说,当我累了
QList<QObject *> datalist;
datalist.append(sampleManager.getSampleList().first());
datalist.append(sampleManager.getSampleList().last());
它成功了。我怎样才能使它与QList<Sample *>
一起工作?
感谢您的帮助!
最佳答案
您可以传递 QObject 列表,但问题是如果添加更多元素,它不会通知 View ,如果您希望通知 View ,则必须使用继承自 QAbstractItemModel 的模型。另一方面,您如何将数据模型作为 qproperty 进行操作,最好公开 SampleManager:
samplemodel.h
#ifndef SAMPLEMODEL_H
#define SAMPLEMODEL_H
#include "sample.h"
#include <QAbstractListModel>
class SampleModel : public QAbstractListModel
{
Q_OBJECT
public:
using QAbstractListModel::QAbstractListModel;
~SampleModel(){
qDeleteAll(mSamples);
mSamples.clear();
}
int rowCount(const QModelIndex &parent = QModelIndex()) const override{
if (parent.isValid())
return 0;
return mSamples.size();
}
QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override{
if (!index.isValid())
return QVariant();
if(role == Qt::UserRole){
Sample *sample = mSamples[index.row()];
return QVariant::fromValue(sample);
}
return QVariant();
}
void appendSample(Sample * sample)
{
beginInsertRows(QModelIndex(), rowCount(), rowCount());
mSamples << sample;
endInsertRows();
}
QHash<int, QByteArray> roleNames() const{
QHash<int, QByteArray> roles;
roles[Qt::UserRole] = "sample";
return roles;
}
private:
QList<Sample *> mSamples;
};
#endif // SAMPLEMODEL_H
samplemanager.h
#ifndef SAMPLEMANAGER_H
#define SAMPLEMANAGER_H
#include "samplemodel.h"
#include <QObject>
class SampleManager : public QObject
{
Q_OBJECT
Q_PROPERTY(SampleModel* model READ model WRITE setModel NOTIFY modelChanged)
public:
using QObject::QObject;
SampleModel *model() const{
return mModel.get();
}
void setModel(SampleModel *model){
if(mModel.get() == model)
return;
mModel.reset(model);
}
signals:
void modelChanged();
private:
QScopedPointer<SampleModel> mModel;
};
#endif // SAMPLEMANAGER_H
main.cpp
#include "samplemanager.h"
#include "samplemodel.h"
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <QTime>
#include <QTimer>
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
SampleManager manager;
manager.setModel(new SampleModel);
// test
QTimer timer;
QObject::connect(&timer, &QTimer::timeout, [&manager](){
manager.model()->appendSample(new Sample(QTime::currentTime().toString()));
});
timer.start(1000);
QQmlApplicationEngine engine;
engine.rootContext()->setContextProperty("manager", &manager);
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
if (engine.rootObjects().isEmpty())
return -1;
return app.exec();
}
main.qml
import QtQuick 2.9
import QtQuick.Window 2.2
Window {
visible: true
width: 640
height: 480
title: qsTr("Hello World")
GridView {
anchors.fill: parent
model: manager.model
delegate:
Rectangle {
width: 100
height: 100
color: "darkgray"
Text {
text: sample.getVar
anchors.centerIn: parent
}
}
}
}
完整的示例可以在下面的link中找到。 .
关于c++ - 将 QList<customobj *> 暴露给 QML,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51149966/