Question

我有列表视图表。每当我尝试从列表视图表中删除项目时，列表的顺序变为随机，但是当我将项目添加到列表中时，列表将被排序。每当删除列表时，我希望其余项目按学生ID排序。到目前为止，我已经尝试过并且没有任何运气。

StudentOrder.xaml

<CollectionViewSource
    Source="{Binding StudentRecords}">
    <CollectionViewSource.SortDescriptions>
    </CollectionViewSource.SortDescriptions>
</CollectionViewSource>

StudentOrder.xaml.cs

void StudentOrder_Loaded(object sender, RoutedEventArgs e)
{
    if (Shows.OrderCurrent == null)
    {
        Show.OrderPresent = StudentID;
        Show.DataOrder = "StudentID";
        Show.Order();
    }
    else
    {
        if (orderLst != null)
        { 
            Show.Order();
        }
    }
}

ShowOrders.cs

public override bool Delete()
{
    recordRetriever.StudentOrderRetriever.Delete(_record);
    Record = null;
    Refresh();
    return true;
}

private ObservableCollection<ShowOrder> RandomListSort()
{
    IEnumerable<ShowOrder> arrangeditems = StudentRecords;
    if (Orderreplaced)
    {
        switch (DataOrder)
        {
            default:
                arrangeditems = StudentRecords.OrderBy(s => s.GetType().GetProperty(DataOrder).GetValue(s, null)).ToList();
                break;
        }
    }
    Orderreplaced = false;
    return new ObservableCollection<RandomListSort>(arrangeditems);
}

public override void Refresh()
{
    Refresh();
    StudentRecords = RandomListSort();
}

Answer 1

您没有为排序说明设置的属性。如果不是你以编程方式进行，那么最好将它设置在XAML中，如下所示。

qry.exec("select * from myTable");

    QByteArray *outByteArray;

    while (qry.next())
        outByteArray = new QByteArray(qry.value("myCol").toByteArray());

    QBuffer *mediaStream = new QBuffer(outByteArray);
    mediaStream->open(QIODevice::ReadOnly);
    QMediaPlayer *player = new QMediaPlayer;
    QVideoWidget *videoWidget = new QVideoWidget(this);
    videoWidget->setGeometry(32, 136, 400, 300);
    player->setVideoOutput(videoWidget);
    player->setMedia(QMediaContent(),mediaStream);
    player->setVolume(50);
    player->play();

有关更多文档，请查看以下链接。

https://msdn.microsoft.com/en-us/library/ms742542(v=vs.110).aspx

从列表中删除列表项以随机顺序记录

1 个答案: