qml 结合 QSqlTableModel 动态加载数据 MVC「建议收藏」

#ifndef LOCALMUSICMODEL_H
#define LOCALMUSICMODEL_H

#include <QObject>
#include <QSqlTableModel>
#include <QMediaPlayer>
#include "libzplay.h"
using namespace libZPlay;

struct songInfo
{
    QString Artist;
    QString title;
    QString album;
    qint32 duration = 0;
    QString path;

};

class LocalMusicModel : public QSqlTableModel
{
    Q_OBJECT
    Q_PROPERTY(int m_musicNum READ musicNum WRITE setMusicNum NOTIFY musicNumChanged)



public:
    explicit LocalMusicModel(QObject *parent = nullptr);
    QVariant data(const QModelIndex &index, int role) const Q_DECL_OVERRIDE;
    QHash<int, QByteArray> roleNames() const Q_DECL_OVERRIDE;

    Q_INVOKABLE void reloadMusicRecord(const QString &path);
    int musicNum(){return m_musicNum;}
    void setMusicNum(int val){
        m_musicNum = val;
        emit musicNumChanged();
    }

signals:
    void musicNumChanged();

private:
    void parseMusicInfo(QString path);
    void clearDb();

private:
    ZPlay *player;
    int m_musicNum = 0;

};

#endif // LOCALMUSICMODEL_H

#include "localmusicmodel.h"

#include <QDateTime>
#include <QSqlRecord>
#include <QDebug>
#include <QSqlError>
#include <QSqlQuery>
#include <QDir>


static const char *localMusicTableName = "LocalMusicInfo";

static void createTable()
{
    if (QSqlDatabase::database().tables().contains(localMusicTableName)) {
        // The table already exists; we don't need to do anything.
        return;
    }

    QSqlQuery query;
    QString sql_ = QStringLiteral("CREATE TABLE IF NOT EXISTS [LocalMusicInfo] (         \
                                  [title] VARCHAR2 , \
                                  [singer] VARCHAR2 , \
                                  [album] VARCHAR2 , \
                                  [duration] INTEGER ,\
                                  [path] VARCHAR2 NOT NULL ,          \
                                  UNIQUE([path]) ON CONFLICT REPLACE \
                                  )");


    if (!query.exec(sql_)) {
        qFatal("Failed to query database: %s", qPrintable(query.lastError().text()));
    }

    //query.exec("INSERT INTO LocalMusicInfo VALUES('title', 'singer', 'album', 123,'c://')");
}


LocalMusicModel::LocalMusicModel(QObject *parent)
    : QSqlTableModel(parent)
{
    createTable();
    setTable(localMusicTableName);
    /*可以看到这个模型很强大，而且完全脱离了SQL语句，就算你不怎么懂数据库，
     * 也可以利用它进行大部分常用的操作。这个模型提供了缓冲区，可以将所有修改先保存到model中，
     * 只有当我们执行提交修改后，才会真正写入数据库。当然这也是因为我们在最开始设置了它的保存策略：
    submitAll();   revertAll();*/
    setEditStrategy(QSqlTableModel::OnManualSubmit);
    select();
    player = CreateZPlay();

    setMusicNum(this->rowCount());
}

QVariant LocalMusicModel::data(const QModelIndex &index, int role) const
{
    if (role < Qt::UserRole)
            return QSqlTableModel::data(index, role);

    const QSqlRecord sqlRecord = record(index.row());

    //qDebug() << sqlRecord.value(role - Qt::UserRole);

    switch (role) {
    case Qt::UserRole:
        if(sqlRecord.value(0).toString().isEmpty())
        {
            QString path = sqlRecord.value(role - Qt::UserRole + 4).toString();
            path =  path.right(path.lastIndexOf('/'));
            path.chop(4);
            return  path.simplified();
        }
        break;
    case Qt::UserRole+1:
        if(sqlRecord.value(1).toString().isEmpty())
            return tr("未知歌手");
        break;
    case Qt::UserRole+2:
        if(sqlRecord.value(2).toString().isEmpty())
            return tr("未知专辑");
        break;
    case Qt::UserRole+3:
        int time = sqlRecord.value(3).toInt();
        return QString("%1:%2").arg(time/60).arg(time%60,2,10,QChar('0'));
    }
    return sqlRecord.value(role - Qt::UserRole);
}

QHash<int, QByteArray> LocalMusicModel::roleNames() const
{
    QHash<int, QByteArray> names;
    names[Qt::UserRole] = "title";
    names[Qt::UserRole + 1] = "singer";
    names[Qt::UserRole + 2] = "album";
    names[Qt::UserRole + 3] = "duration";
    names[Qt::UserRole + 4] = "path";
    return names;
}

void LocalMusicModel::reloadMusicRecord(const QString &path_)
{
    parseMusicInfo(path_);
}

//获取指定目录下所有歌曲信息
void LocalMusicModel::parseMusicInfo(QString path)
{
    QList<songInfo> songRecords;
    QStringList dirList=path.split(",");
    QString temp;
    foreach (temp, dirList) {
        temp=temp.right(temp.length()-8);
        QDir dir(temp);
        dir.setNameFilters(QStringList() << "*.mp3" << "*.flac" << "*.wav");
        QFileInfoList fileList=dir.entryInfoList();
        QFileInfo fileInfo;

        foreach (fileInfo, fileList) {
            TID3InfoEx id3_info;
            //如果直接使用LoadFileID3Ex函数，会得不到时长信息
            if(player->OpenFile((const char*) fileInfo.absoluteFilePath().toLocal8Bit(),sfAutodetect))
                if(player->LoadID3Ex(&id3_info,1))
                {
                    songInfo tempSongInfo;
                    tempSongInfo.title = QString::fromLocal8Bit(id3_info.Title);    //音乐标题
                    tempSongInfo.Artist = QString::fromLocal8Bit(id3_info.Artist);  //歌手
                    tempSongInfo.path = fileInfo.absoluteFilePath();                //路径
                    tempSongInfo.album = QString::fromLocal8Bit(id3_info.Album);    //专辑
                    // get stream info,获取时长信息
                    TStreamInfo pInfo;
                    player->GetStreamInfo(&pInfo);
                    tempSongInfo.duration =pInfo.Length.sec;
                    songRecords.append(tempSongInfo);
                }
                else
                {
                    qDebug() << QString("No ID3 data:%1\r\n\r\n").arg(QString::fromLocal8Bit(player->GetError()));
                }
            else
            {
                qDebug() << "LoadID3Ex faild";
            }
        }
    }

    clearDb();

    QSqlRecord newRecord = record();
    for(auto songItem : songRecords)
    {
        newRecord.setValue("title", songItem.title);
        newRecord.setValue("singer", songItem.Artist);
        newRecord.setValue("album", songItem.album);
        newRecord.setValue("duration", songItem.duration);
        newRecord.setValue("path", songItem.path);

        if (!insertRecord(rowCount(), newRecord)) {
            qWarning() << "Failed to send message:" << lastError().text();
            return;
        }
    }

    submitAll();//提交数据库
    setMusicNum(songRecords.size());
}

void LocalMusicModel::clearDb()
{
    if (!QSqlDatabase::database().tables().contains(localMusicTableName)) {
        createTable();
    }

    QSqlQuery query;
    QString sql_ = QStringLiteral("delete from [LocalMusicInfo]");

    if (!query.exec(sql_)) {
        qFatal("Failed to query database: %s", qPrintable(query.lastError().text()));
    }
    qDebug() << "clear table ok";
}

QHash<int, QByteArray> roleNames() const Q_DECL_OVERRIDE;

QVariant data(const QModelIndex &index, int role) const Q_DECL_OVERRIDE;

qmlRegisterType<LocalMusicModel>("io.qt.CloudMusic", 1, 0, "LocalMusicModel");

import io.qt.CloudMusic 1.0

LocalMusicModel{
 
 id:localmusic;}

            TableView{
                id: tableview
                anchors.fill: parent
                visible: localmusic.m_musicNum >0
                backgroundVisible: false;
                frameVisible: false;
                //itemDelegate: StandardTabelItemDelegate{} //代理
                //headerDelegate: headerDele;  //表头委托
                //rowDelegate: rowDele;   //行委托
                model: localmusic

                TableViewColumn {
                          role: "title"
                          title: qsTr("标题")
                          width: 300
                      }
                TableViewColumn {
                          role: "singer"
                          title: qsTr("歌手")
                          width: 300
                      }
                TableViewColumn {
                          role: "album"
                          title: qsTr("专辑")
                          width: 300
                      }
                TableViewColumn {
                          role: "duration"
                          title: qsTr("时长")
                          width: 300
                      }
            }