一、适用情况
在C++里将数据生成，然后将这个数据设置为qml的上下文属性，在qml里就能使用了
二、传递基础类型
1、main.cpp
QQuickWidget *m_widget = new QQuickWidget(this); m_widget->setGeometry(0, 0, this->width(), this->height()); //关键代码 QString str = "zhuxy"; m_widget->rootContext()->setContextProperty("Zhuxy",str); m_widget->setSource(QUrl("./main.qml")); m_widget->show();
2、main.qml
import QtQuick 2.0 Rectangle { id: mainWindow x: 30; y: 80; 1000; height: 800; Component.onCompleted: { console.log(Zhuxy); } }
这里直接能用Zhuxy这个上下文属性
三、ListView+QStringList作为model
1、main.cpp
QStringList list; list << "1" << "2"; m_widget->rootContext()->setContextProperty("Zhuxy",QVariant::fromValue(list));//不能是Test？？ m_widget->setSource(QUrl("./test.qml")); m_widget->show();
2、test.qml
import QtQuick 2.0
ListView { 100; height: 100 model: myModel delegate: Rectangle { height: 25 100 Text { text: modelData } } }
注意：经过测试这个上下文属性不能取名为Test（可能已经是内置上下文属性）
四、ListView+qml可访问的C++类
1、
mydata.h
#ifndef MYDATA_H #define MYDATA_H #include <QObject> class Mydata : public QObject { Q_OBJECT Q_PROPERTY(QString value READ value WRITE setValue NOTIFY valueChanged) Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged) public: Mydata(QObject *parent = nullptr); Mydata(const QString &value, const QString &name, QObject *parent = nullptr); QString value()const; void setValue(const QString &value); QString name()const; void setName(const QString& name); signals: void valueChanged(); void nameChanged(); private: QString m_value; QString m_name; }; #endif // MYDATA_H
value和name就是qml可访问的值
mydata.cpp
#include "mydata.h" Mydata::Mydata(QObject *parent) : QObject(parent) { } Mydata::Mydata(const QString &value, const QString &name, QObject *parent) : QObject(parent),m_value(value),m_name(name) { } QString Mydata::value() const { return m_value; } void Mydata::setValue(const QString &value) { if(this->m_value != value) { this->m_value = value; emit valueChanged(); } } QString Mydata::name() const { return m_name; } void Mydata::setName(const QString &name) { if(this->m_name != name) { this->m_name = name; emit nameChanged(); } }
2、test.qml
import QtQuick 2.0 Rectangle { id: mainWindow x: 30; y: 80; 1000; height: 800; ListView { anchors.fill: parent; model: ParaListModel; delegate: delegate_list spacing: 20; orientation: ListView.Horizontal //委托 Component { id: delegate_list; Rectangle { id: rect; 80; height: width; color: "green"; Text { id: text1; text: value; horizontalAlignment: Text.AlignHCenter; verticalAlignment: Text.AlignVCenter; font.pixelSize: 16; anchors.horizontalCenter: parent.horizontalCenter; anchors.top: parent.top; anchors.topMargin: 10; color: "white"; } Text { id: text2; text: name; horizontalAlignment: Text.AlignHCenter; verticalAlignment: Text.AlignVCenter; font.pixelSize: 16; anchors.horizontalCenter: parent.horizontalCenter; anchors.bottom: parent.bottom; anchors.bottomMargin: 10; color: "white"; } } } } }
3、main.cpp
QList<QObject*> datalist; datalist.append(new Mydata("item1", "red")); datalist.append(new Mydata("item2", "green")); datalist.append(new Mydata("item3", "blue")); datalist.append(new Mydata("item4", "yellow")); m_widget->rootContext()->setContextProperty("ParaListModel",QVariant::fromValue(datalist));
注意必须是QObject指针类型才能放进list等容器里，因为QObject的赋值构造函数是delete的
五、ListView+QAbstractListModel子类
上面的几种不支持动态更新数据，现在这种方式支持动态更新数据，当时当list的个数增加或减少是不支持更新的。
1、C++模型类ParaListModel.h
#ifndef PARALISTMODEL_H #define PARALISTMODEL_H #include <QAbstractListModel> struct ParaModel { ParaModel() { value = ""; nodeName = ""; nodeType = ""; tableName = ""; fieldName = ""; module = ""; location = ""; rectRadius = -1; } //核心属性 QString value; QString nodeName; QString nodeType; QString tableName; QString fieldName; //附加属性 QString module; QString location; int rectRadius; }; class ParaListModel : public QAbstractListModel { Q_OBJECT public: ParaListModel(QObject* parent = 0); enum Roles//qml用来识别别名的规则 { valueRole = Qt::UserRole + 1, nodeNameRole, nodeTypeRole, tableNameRole, fieldNameRole, moduleRole, locationRole, rectRadiusRole }; void addModel(const ParaModel &deviceList);//C++设置值 void update(int index, const ParaModel ¶Model);//C++更新 int rowCount(const QModelIndex &parent = QModelIndex()) const;//qml内部调用,不用多管直接重写即可 QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;//qml内部调用,不用多管直接重写即可 protected: QHash<int, QByteArray> roleNames() const;//qml内部调用,不用多管直接重写即可 private: QList<ParaModel> m_data; }; #endif // PARALISTMODEL_H
C++模型类ParaListModel.cpp
#include "paralistmodel.h" ParaListModel::ParaListModel(QObject *parent) : QAbstractListModel(parent) { } void ParaListModel::addModel(const ParaModel ¶Model) { beginInsertRows(QModelIndex(), rowCount(), rowCount()); m_data << paraModel; endInsertRows(); } int ParaListModel::rowCount(const QModelIndex &parent) const { Q_UNUSED(parent); return m_data.count(); } QVariant ParaListModel::data(const QModelIndex &index, int role) const { if (index.row() < 0 || index.row() >= m_data.count()) return QVariant(); const ParaModel ¶Model = m_data[index.row()]; switch (role) { case valueRole: return paraModel.value; break; case nodeNameRole: return paraModel.nodeName; break; case nodeTypeRole: return paraModel.nodeType; break; case tableNameRole: return paraModel.tableName; break; case fieldNameRole: return paraModel.fieldName; break; case moduleRole: return paraModel.module; break; case locationRole: return paraModel.location; break; case rectRadiusRole: return paraModel.rectRadius; break; default: break; } return QVariant(); } void ParaListModel::update(int index, const ParaModel ¶Model) { if (index < 0 || index >= m_data.count()) return; ParaModel &srcModel = m_data[index]; if(paraModel.value != "") { srcModel.value = paraModel.value; } if(paraModel.nodeName != "") { srcModel.nodeName = paraModel.nodeName; } if(paraModel.nodeType != "") { srcModel.nodeType = paraModel.nodeType; } if(paraModel.tableName != "") { srcModel.tableName = paraModel.tableName; } if(paraModel.fieldName != "") { srcModel.fieldName = paraModel.fieldName; } if(paraModel.module != "") { srcModel.module = paraModel.module; } if(paraModel.location != "") { srcModel.location = paraModel.location; } if(paraModel.rectRadius != -1) { srcModel.rectRadius = paraModel.rectRadius; } } //qml通过这里的QByteArray来访问数据 QHash<int, QByteArray> ParaListModel::roleNames() const { QHash<int, QByteArray> roles; roles[valueRole] = "value"; roles[nodeNameRole] = "nodeName"; roles[nodeTypeRole] = "nodeType"; roles[tableNameRole] = "tableName"; roles[fieldNameRole] = "fieldName"; roles[moduleRole] = "module"; roles[locationRole] = "location"; roles[rectRadiusRole] = "rectRadius"; return roles; }
qml通过3个重写的函数来获取每个model的值：
首先通过rouCount获取model个数；
再通过roleNames获取每个变量名和其role的值；
最后根据role的值访问data函数，获取到真实值
2、test.qml
import QtQuick 2.0 Rectangle { 800; height: 300; color: "#222648";//背景色 property int rect_ 80;//参数宽度 property color text_color: "white";//字体颜色 ListView { parent.width; height: rect_width; anchors.centerIn: parent; model: ParaListModel; delegate: delegate_list spacing: 20; orientation: ListView.Horizontal } //委托 Component { id: delegate_list; Rectangle { id: rect; rect_width; height: width; radius: rectRadius; color: bkColor; property string q_tableName: tableName;//其他不用显示的属性 property string q_fieldName: fieldName; Text { id: text1; text: value; horizontalAlignment: Text.AlignHCenter; verticalAlignment: Text.AlignVCenter; font.pixelSize: 16; anchors.horizontalCenter: parent.horizontalCenter; anchors.top: parent.top; anchors.topMargin: 10; color: text_color; } Text { id: text2; text: nodeName; horizontalAlignment: Text.AlignHCenter; verticalAlignment: Text.AlignVCenter; font.pixelSize: 16; anchors.horizontalCenter: parent.horizontalCenter; anchors.bottom: parent.bottom; anchors.bottomMargin: 10; color: text_color; } MouseArea { anchors.fill: parent; hoverEnabled: true; cursorShape: (containsMouse? (pressed? Qt.ClosedHandCursor: Qt.OpenHandCursor): Qt.ArrowCursor);//设置鼠标样式 onDoubleClicked: { console.log(q_tableName,q_fieldName); } } } } }
3、main.cpp
m_widget = new QQuickWidget(this); m_widget->setGeometry(0, 0, this->width(), this->height()); //关键代码 ParaListModel modelList; for(int i=0;i<5;i++) { ParaModel model; model.value = "value:"+QString::number(i); model.nodeName = "nodeName:"+QString::number(i); model.nodeType = "nodeType:"+QString::number(i); model.tableName = "tableName:"+QString::number(i); model.fieldName = "fieldName:"+QString::number(i); model.rectRadius = 40; modelList.addModel(model); } m_widget->rootContext()->setContextProperty("ParaListModel",&modelList); //测试实时更新qml中的值 ParaModel model; model.value = "new"; model.nodeName = "new"; model.rectRadius = 10; modelList.update(4,model);
