wpf - 刷新视图时,CollectionView.filter 委托未触发
问题描述
我有 Observable 集合。我在集合更改事件中应用过滤器。这样我就可以在数据网格中过滤项目。请在下面找到代码片段,
private void Button_Click_2(object sender, RoutedEventArgs e)
{
vm.Customers.Add(new Customer() { Name = "Customer1", OrderName = "Order1" });
vm.Customers.Add(new Customer() { Name = "Customer2", OrderName = "Order2" });
vm.Customers.Add(new Customer() { Name = "Customer3", OrderName = "Order3" });
vm.Customers.Add(new Customer() { Name = "Customer4", OrderName = "Order4" });
vm.Customers.Add(new Customer() { Name = "Customer5", OrderName = "Order5" });
}
private void Customers_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
ICollectionView _customerView = CollectionViewSource.GetDefaultView(vm.Customers);
if(_customerView!=null)
{
_customerView.Filter = delegate (object item)
{
Customer customer = item as Customer;
return customer.Name.Contains("Customer3");
};
}
}
我正在更新我的 viewModel 集合,然后我正在刷新视图,
private void Button_Click_1(object sender, RoutedEventArgs e)
{
vm.Customers = new System.Collections.ObjectModel.ObservableCollection<Customer>();
vm.Customers.Add(new Customer() { Name = "Customer1", OrderName = "1" });
vm.Customers.Add(new Customer() { Name = "Customer2", OrderName = "2" });
vm.Customers.Add(new Customer() { Name = "Customer3", OrderName = "3" });
ICollectionView _customerView = CollectionViewSource.GetDefaultView(vm.Customers);
_customerView.Refresh();
}
但是我的 view.filter 委托没有被调用。因此无法过滤集合。
我的观点:
<UserControl x:Class="WpfApplication3.UserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:WpfApplication3"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.DataContext>
<local:UserControlViewModel/>
</UserControl.DataContext>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<DataGrid AutoGenerateColumns="True" x:Name="list" ItemsSource="{Binding Customers}" />
<Button Content="Add customers" Height="50" Width="100" Grid.Column="1" Click="Button_Click_2"/>
<Button Content="Filter customer3" Height="50" Width="100" Grid.Column="2" Click="Button_Click"/>
<Button Content="Add items" Height="50" Width="100" Grid.Column="3" Click="Button_Click_1"/>
</Grid>
请任何人帮助我在通过按钮单击刷新视图时触发过滤器委托。
谢谢
解决方案
不要创建新的集合 - 你会得到一个不同的 collectionView !该 collectionView 未连接到视图。
尝试清除集合:
private void Button_Click_1(object sender, RoutedEventArgs e)
{
vm.Customers.Clear();
vm.Customers.Add(new Customer() { Name = "Customer1", OrderName = "1" });
vm.Customers.Add(new Customer() { Name = "Customer2", OrderName = "2" });
vm.Customers.Add(new Customer() { Name = "Customer3", OrderName = "3" });
ICollectionView _customerView = CollectionViewSource.GetDefaultView(vm.Customers);
_customerView.Refresh();
}
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