[英]mvvm binding selecteditem to update listview
我是MVVM的新手,並且一直試圖將工作程序轉換為MVVM程序。 我一直在尋找答案,但到目前為止還沒有運氣。
基本上我擁有的是:列表框和列表視圖。 列表框中填充了Trainstations,我想在列表視圖中顯示站點的時間(有延遲等)。 列表框中充滿了工作站,每當我選擇一個工作站時,它都會更新,我將它放在一個名為“CurrentStation”的變量中。 現在我正在使用這個'CurrentStation'獲取一個ObservableCollection列表,列出該站的所有離開,但由於某種原因,該功能只被調用一次,並且當我選擇另一個站時不會更新。
我也不知道在xaml代碼中綁定什么。
<ListBox x:Name="lstStations" Margin="8" Grid.Row="1" ItemsSource="{Binding StationList}" SelectedItem="{Binding CurrentStation}" DisplayMemberPath="Name"/>
<ListView Grid.Column="1" Margin="8" Grid.Row="1" ItemsSource="{Binding Departures}" >
<ListView.View>
<GridView>
<GridViewColumn DisplayMemberBinding="{Binding Time, StringFormat=t}" Header="Time" />
<GridViewColumn DisplayMemberBinding="{Binding Delay, Converter={StaticResource mijnDelayConverter}}" Header="Delay"/>
<GridViewColumn DisplayMemberBinding="{Binding Station}" Header="Station"/>
<GridViewColumn DisplayMemberBinding="{Binding Vehicle}" Header="Vehicle"/>
<GridViewColumn Header="Platform" CellTemplate="{DynamicResource dataTemplateTextblock}" />
<!-- Haven't had the chance to look at this ^ I don't think this is correct though -->
</GridView>
</ListView.View>
</ListView>
這是ViewModel代碼:
public string Name
{
get
{
return "MainPage";
}
}
public ObservableCollection<Station> StationList
{
get
{
return Station.GetStations();
}
}
private Station _currentStation;
public Station CurrentStation
{
get
{
return _currentStation;
}
set
{
_currentStation = value;
Console.WriteLine("New station selected: " + _currentStation.ToString());
OnPropertyChanged("CurrentStation");
}
}
private ObservableCollection<Departure> _departures;
public ObservableCollection<Departure> Departures
{
get
{
return Departure.GetDepartures(CurrentStation);
}
set
{
_departures = value;
}
}
我想你需要:
明確更新Departures
屬性,可以在CurrentStation
setter中完成
private Station _currentStation; public Station CurrentStation { get { return _currentStation; } set { _currentStation = value; Departures = Departure.GetDepartures(_currentStation); Console.WriteLine("New station selected: " + _currentStation.ToString()); OnPropertyChanged("CurrentStation"); } }
觸發更改通知,該更改通知將使用着名的OnPropertyChanged
刷新離開綁定(和列表框!)
private ObservableCollection<Departure> _departures; public ObservableCollection<Departure> Departures { get { return _departures } set { _departures = value; OnPropertyChanged("Departures"); } }
您還必須在Observabe集合上設置OnPropertyChanged
public ObservableCollection<Departure> Departures
{
get
{
return Departure.GetDepartures(CurrentStation);
}
set
{
_departures = value; OnPropertyChanged("Departures")
}
}
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