Question

也许我的问题不清楚，但我希望通过代码我的问题变得更加明确。我有一个创建这两个结构，我在FormModel类中使用它们：

struct Tile
{
    QString name;
    QString color;
};  Q_DECLARE_METATYPE(Tile)

struct Form
{
    QString nameForm;
    Tile grid[9] ;   // i want for each form 4 tile that in qml are 4 rectangles
}; Q_DECLARE_METATYPE(Form)



class FormModel : public QAbstractListModel
{
    Q_OBJECT
public:
    explicit FormModel(QObject *parent = 0);

    ~FormModel();
    enum dashBoardRoles {

        NameForm=Qt::UserRole+1,
        Grid,

     };

    int rowCount(const QModelIndex &parent=QModelIndex()) const;
    QVariant data(const QModelIndex &index, int role) const;
    Q_INVOKABLE bool insertRows(int row, int count, const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;
    Q_INVOKABLE bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;
    QHash<int, QByteArray> roleNames() const;

signals:

public slots:

private:

  QList<Form> dashboard;


};

这是QAbstractListModel的数据方法：

QVariant FormModel::data(const QModelIndex &index, int role) const
{
    if(index.row()>0 && index.row() >= dashboard.count())
        return QVariant();
    Form dashTemp = dashboard[index.row()];

    if(role== NameForm)
        return dashTemp.nameForm;
    if(role== Grid)
    {
        QVariant gridVect = QVariant::fromValue(dashTemp.grid);
        return gridVect;
    }
    return QVariant();
}

QHash<int, QByteArray> FormModel::roleNames() const
{
    QHash <int,QByteArray> roles;
    roles [NameForm]="nameForm";
    roles [Grid]="grid";

    return roles;
}

这是qml代码：

Window {
    id:app
    visible: true
    width: 480
    height: 800
    title: qsTr("Hello World")

    ListView {

     model: myForms  // i have defined the name in main.cpp
     anchors.fill: parent

     delegate:  ColumnLayout{
          spacing: 30
          // nome Form
          Text{

              text: nameForm
              font.pointSize:20
              color: "red"
              font.capitalization: Font.Capitalize

          }
          // grigla mattonelle
          GridView {
              id:grid

              width: 300; height: 300
              cellWidth: 100 ; cellHeight: 100
              model: 9
              delegate: Item{
                  width : grid.cellWidth
                  height: grid.cellHeight
                  Rectangle{
                      anchors.centerIn: parent
                      width:parent.width-10
                      height: parent.height-10
                      color: grid[index].color
                  }

              }
         }
       }
    }

}

我如何从角色Grid的数据中获取颜色？我在qml中调用grid [index] .color ....

Answer 1

QML不直接识别结构，为此您必须将Q_GADGET与Q_PROPERTY一起使用，建议使用QVariantList而不是数组，因为QML可以直接转换它。以上所有我都在以下代码中实现了它：

<强> formmodel.h

#ifndef FORMMODEL_H
#define FORMMODEL_H

#include <QAbstractListModel>

struct Tile
{
    Q_GADGET
    Q_PROPERTY(QString name MEMBER name)
    Q_PROPERTY(QString color MEMBER color)
public:
    QString name;
    QString color;
    Tile(const QString& name="", const QString& color=""){
        this->name = name;
        this->color = color;
    }
};
Q_DECLARE_METATYPE(Tile)

struct Form
{
    Q_GADGET
    Q_PROPERTY(QString nameForm MEMBER nameForm)
    Q_PROPERTY(QVariantList grid MEMBER grid)
public:
    Form(){
    }
    QString nameForm;
    QVariantList grid;
};
Q_DECLARE_METATYPE(Form)

class FormModel : public QAbstractListModel
{
    enum dashBoardRoles {
        NameForm=Qt::UserRole+1,
        Grid
    };
public:
    FormModel(QObject *parent = Q_NULLPTR);
    QHash<int, QByteArray> roleNames() const;
    int rowCount(const QModelIndex &parent=QModelIndex()) const;
    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const;
private:
    QList<Form> dashboard;
};

#endif // FORMMODEL_H

<强> formmodel.cpp

#include "formmodel.h"

#include <QColor>

FormModel::FormModel(QObject *parent):QAbstractListModel(parent)
{
    for(int i=0; i<10; i++){
        Form form;
        form.nameForm = QString("name %1").arg(i);
        for(int j=0; j<9; j++){
            QColor color(qrand() % 256, qrand() % 256, qrand() % 256);
            Tile tile{QString("name %1 %2").arg(i).arg(j), color.name()};
            form.grid<< QVariant::fromValue(tile);
        }
        dashboard<< form;
    }
}


QHash<int, QByteArray> FormModel::roleNames() const
{
    QHash <int,QByteArray> roles;
    roles [NameForm]="nameForm";
    roles [Grid]="grid";
    return roles;
}

int FormModel::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent)
    return dashboard.count();
}

QVariant FormModel::data(const QModelIndex &index, int role) const
{
    if(index.row()<0 && index.row() >= dashboard.count())
        return QVariant();
    Form dashTemp = dashboard[index.row()];
    if(role== NameForm)
        return dashTemp.nameForm;
    else if(role== Grid)
        return dashTemp.grid;
    return QVariant();
}

<强> main.qml

import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Layouts 1.3


Window {
    id:app
    visible: true
    width: 480
    height: 800
    title: qsTr("Hello World")

    ListView {

        model: myForms
        anchors.fill: parent
        delegate:  ColumnLayout{
            spacing: 30
            Text{
                text: nameForm
                font.pointSize:20
                color: "red"
                font.capitalization: Font.Capitalize
            }
            GridView {
                id:gr
                width: 300; height: 300
                cellWidth: 100 ; cellHeight: 100
                model: grid // grid.length
                delegate: Item{
                    width : gr.cellWidth
                    height: gr.cellHeight
                    Rectangle{
                        anchors.centerIn: parent
                        width:parent.width-10
                        height: parent.height-10
                        color: grid[index].color
                        Text {
                            id: name
                            anchors.fill: parent
                            text: grid[index].name
                        }
                    }

                }

            }
        }
    }

}

完整示例可在以下link中找到。

我怎么能拥有作为数组的QAbstractListModel的访问角色？

1 个答案: