Question

我的应用程序中有一个窗口，其中包含以下资源：

 <Window.Resources>
    <ResourceDictionary>
        <Data:IssueRecords x:Key="DataSource"/>
        <CollectionViewSource x:Key="DataCollection" Source="{StaticResource DataSource}"
                              Filter="CollectionViewSource_Filter">
        </CollectionViewSource>
    </ResourceDictionary>
</Window.Resources>

有一个标准的事件处理程序 - 一个名为CollectionViewSource_Filter和DataGrid的方法，用于应用过滤器。我的窗口加载后，一切都很完美，包括过滤器。

为了应用过滤器，我调用了ReloadGrid方法......

    private void ReloadGrid(object sender, RoutedEventArgs e)
    {
        CollectionViewSource.GetDefaultView(GridData.ItemsSource).Refresh();
    }

但是，当用户执行任何操作（对我的数据库进行更改（删除，修改或创建新）时），我需要重新加载这些数据源，所以我打电话给...

    private void ReloadDataSources()
    {
        var dataSource = this.FindResource("DataSource") as IStockRecords;
        dataSource.ReloadData();

        var dataCollection = this.FindResource("DataCollection") as CollectionViewSource;
        dataCollection = new CollectionViewSource() { Source = dataSource };
        dataCollection.Filter += new FilterEventHandler(CollectionViewSource_Filter);

        Binding binding = new Binding() { Source = dataCollection };
        BindingOperations.SetBinding(GridData, DataGrid.ItemsSourceProperty, binding);
    }

我认为，我做了所有事情，从数据库中读取实际数据并在窗口中重新加载数据源所需的一切。但是当我使用任何过滤器时，在调用ReloadDataSources（）之后，过滤器事件不再被使用。我调试了一个源代码，而且当我设置FilterEventHandler时，Refresh方法不会调用CollectionViewSource_Filter ......

我错过了什么吗？谢谢，JiKra

Answer 1

修改数据源后，您需要重置默认视图。

CollectionViewSource.GetDefaultView(GridData.ItemsSource).Refresh();

试试这个......

    private void ReloadDataSources()
{
    var dataSource = this.FindResource("DataSource") as IStockRecords;
    dataSource.ReloadData();

    var dataCollection = this.FindResource("DataCollection") as CollectionViewSource;
    // Remove the current event handler
    dataCollection.Filter -= new FilterEventHandler(CollectionViewSource_Filter);
    // Set your new data source
    dataCollection = new CollectionViewSource() { Source = dataSource };
    // Read your handler
    dataCollection.Filter += new FilterEventHandler(CollectionViewSource_Filter);
    // Now reset your filter
    dataCollection .GetDefaultView(GridData.ItemsSource).Refresh();
    Binding binding = new Binding() { Source = dataCollection };
    BindingOperations.SetBinding(GridData, DataGrid.ItemsSourceProperty, binding);
}

Answer 2

好的，我重新创建CollectionViewSource对象时似乎有问题。所以，最终版本是......

private void ReloadDataSources()
{
    var dataSource = this.FindResource("DataSource") as IStockRecords;
    dataSource.ReloadData();
    var dataCollection = this.FindResource("DataCollection") as CollectionViewSource;
    //here I just had to refresh collection's view, not to create a new one
    dataCollection.View.Refresh();
    Binding binding = new Binding() { Source = dataCollection };
    BindingOperations.SetBinding(GridData, DataGrid.ItemsSourceProperty, binding);
}

谢谢你的努力...... JiKra

CollectionViewSource.Filter不起作用

2 个答案: