c++ - QMediaPlaylist::addMedia() 对不存在的文件返回 true

Question

文档说 QMediaPlaylist::addMedia 如果失败则返回 false:

bool QMediaPlaylist::addMedia(const QMediaContent & content) Append the media content to the playlist. Returns true if the operation is successful, otherwise return false.

但是即使文件不存在，这段代码也会打印 true:

QMediaPlayer *player = new QMediaPlayer;
QMediaPlaylist *playlist = new QMediaPlaylist(player);
qDebug() << playlist->addMedia(QUrl("this file doesn't exist.mp4"));

如果文件不存在怎么算操作成功？

Answer 1

进入 Qt 源后，我看到 QMediaPlaylist::addMedia() 调用 QMediaNetworkPlaylistProvider::addMedia()，它总是返回 true:

bool QMediaPlaylist::addMedia(const QMediaContent &content)
{
    return d_func()->control->playlistProvider()->addMedia(content);
}

bool QMediaNetworkPlaylistProvider::addMedia(const QMediaContent &content)
{
    Q_D(QMediaNetworkPlaylistProvider);

    int pos = d->resources.count();

    emit mediaAboutToBeInserted(pos, pos);
    d->resources.append(content);
    emit mediaInserted(pos, pos);

    return true;
}

尽管为什么它需要返回一个始终为真的 bool 值对我来说是个谜。