使用ICollectionView过滤ObservableCollection [英] Filtering ObservableCollection with ICollectionView

问题描述

我将 ObservableCollection 绑定到 dataGrid ，现在我想过滤显示的数据，我看到我需要使用 ICollectionView ，但是我不确定如何在 MVVM ICollectionView $ c>模式。

I have ObservableCollection binded to dataGrid and now I want to filter the presented data I see that I need to use ICollectionView but I am not sure how to add ICollectionView with my MVVM pattern.

我的简化代码如下：

public class MainViewModel : ViewModelBase , IBarcodeHandler
{
    public ObservableCollection<TraceDataItem> TraceItemCollectionViewSource { get; set; }
}

我的XAML

    <Window xmlns:controls="clr-namespace:Mentor.Valor.vManage.RepairStation.Controls"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
            xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
            <DataGrid Grid.Row="2" ColumnWidth="*"  ItemsSource="{Binding TraceItemCollectionViewSource , Mode=TwoWay , UpdateSourceTrigger=PropertyChanged}" RowStyle="{StaticResource TraceRowStyle}"  IsReadOnly="True" Name="TraceDataGrid" Margin="5,5,5,5" Padding="5,5,5,5" AutoGenerateColumns="False">
    </Window>

如何在此处按顺序添加 ICollectionView 要对视图应用过滤？

How I can add ICollectionView here in order to apply filtering to the view?

推荐答案

您将需要：

public class MainViewModel : ViewModelBase, IBarcodeHandler
{
    public ICollectionView TraceItemCollectionView
    {
        get { return CollectionViewSource.GetDefaultView(TraceItemCollectionViewSource); }
    }

    public ObservableCollection<TraceDataItem> TraceItemCollectionViewSource { get; set; }
}

然后，在代码中的某个地方（可能在构造函数中）添加过滤器：

then, somewhere in the code (maybe in the constructor) add your filter:

TraceItemCollectionView.Filter = o =>
{
    var item = (TraceDataItem) o;

    //based on item, return true if it should be visible, or false if not

    return true;
};

而且，在XAML中，您需要更改对TraceItemCollectionView属性的绑定。

And, in XAML, you would need to change the binding to TraceItemCollectionView property.

这篇关于使用ICollectionView过滤ObservableCollection的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！