使用MVVM WPF进行数据网格绑定(Datagrid Binding Using MVVM WPF)

我在两个不同的地方使用mvvm面临数据网格绑定问题。我的datagrid（xaml）的标题是：

clealy说

ItemsSource="{Binding Path=Configurations, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"

在我的viewmodel中：

public ObservableCollection<ViewerConfiguration> Configurations { get { return m_tasks; } set { m_tasks = value; OnPropertyChanged("Configurations"); } }

列表中的数据在视图上正确显示，但问题在于插入和删除（即使它成功更新）。我有一个在Configuration对象中插入项的函数

private void Refresh() { List<ViewerConfiguration> newlyAddedFiles = GetConfigurations(); foreach (ViewerConfiguration config in newlyAddedFiles) { Configurations.Add(config); } }

并删除像：

Configurations.Remove(configuration);

问题实际上是插入和删除。在调试时没有异常，它也成功从集合中删除，但UI没有收到通知。任何猜测为什么这种行为？

另外：我在datagrid下面有一个事件触发器：

<i:Interaction.Triggers> <i:EventTrigger EventName="SelectionChanged"> <i:InvokeCommandAction Command="{Binding RenderPdf}" CommandParameter="{Binding SelectedItem, ElementName=MainGrid}"></i:InvokeCommandAction> </i:EventTrigger> </i:Interaction.Triggers>

我正在从ViewModel的构造函数中调用Refresh函数，只是为了查看它是否有效。

I'm facing an issue in datagrid binding using mvvm on two different places. Headers of my datagrid (xaml) is:

which clealy says

ItemsSource="{Binding Path=Configurations, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"

In my viewmodel:

public ObservableCollection<ViewerConfiguration> Configurations { get { return m_tasks; } set { m_tasks = value; OnPropertyChanged("Configurations"); } }

The data that in the list is shown properly on the view but the problem is with the insert and delete (even it updates successfully). I have a function which inserts an item in the Configuration object

private void Refresh() { List<ViewerConfiguration> newlyAddedFiles = GetConfigurations(); foreach (ViewerConfiguration config in newlyAddedFiles) { Configurations.Add(config); } }

and removes like:

Configurations.Remove(configuration);

The problem is really with the insert and delete. On debugging there is no exception and it successfully deletes from collection too but UI doesn't get a notification. Any guesses why is this behavior?

Additionally: I have an event trigger just under the datagrid:

<i:Interaction.Triggers> <i:EventTrigger EventName="SelectionChanged"> <i:InvokeCommandAction Command="{Binding RenderPdf}" CommandParameter="{Binding SelectedItem, ElementName=MainGrid}"></i:InvokeCommandAction> </i:EventTrigger> </i:Interaction.Triggers>

and I'm calling Refresh function from the constructor of ViewModel just to see if it works or not.

最满意答案

最后我解决了我遇到的问题。基本上有两个问题。在我的配置的getter中，我在排序和过滤前一个集合之后返回一个新的可观察集合。第二个主要问题：

'This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread'

这是我最好的猜测，我将刷新功能更改为：

private void Refresh() { try { List<ViewerConfiguration> newlyAddedFiles = GetConfigurations(); //should not update on other thread than on main thread App.Current.Dispatcher.BeginInvoke((ThreadStart)delegate() { foreach (ViewerConfiguration config in newlyAddedFiles) { Configurations.Add(config); } }); } catch (Exception ex) { } }

现在，它的工作。谢谢

Finally I solved the issue i was having. There were basically two problems. In the getter of my Configurations, i was return a new observable collection after sorting and filtering the previous one. The second main problem:

'This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread'

That was my best guess and i changed my refresh function to:

private void Refresh() { try { List<ViewerConfiguration> newlyAddedFiles = GetConfigurations(); //should not update on other thread than on main thread App.Current.Dispatcher.BeginInvoke((ThreadStart)delegate() { foreach (ViewerConfiguration config in newlyAddedFiles) { Configurations.Add(config); } }); } catch (Exception ex) { } }

Now, its working. Thanks

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