wpf - WPF，MVVM使用另一个组合框选择项填充组合框

我有2个组合框，第一个的选定项需要更改第二个的项源，而没有。

这是我的xaml ...

<ComboBox Grid.Column="1" ItemsSource="{Binding StationsList}" DisplayMemberPath="Value" SelectedValuePath="Key" SelectedValue="{Binding Path=StationTarget, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

<ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding MonitorsList}" DisplayMemberPath="Value" SelectedValuePath="Key" SelectedValue="{Binding Path=MonitorTarget, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

这是viewModel的相关属性和功能...

public ObservableCollection<StationViewModel> Stations
{
    get { return _stations; }
    set
    {
        if (_stations == value)
            return;
        _stations = value;
        SetStationList();
        OnPropertyChanged("Stations");
    }
}

public Dictionary<int,string> StationsList
{
    get
    {
        return _stationsList;
    }
    set
    {
        if (_stationsList == null)
            return;
        _stationsList = value;
        OnPropertyChanged("StationsList");
    }
}

public ObservableCollection<MonitorViewModel> Monitors
{
    get { return _monitors; }
    set
    {
        if (_monitors == value)
            return;
        _monitors = value;
        SetMonitorsList();
        OnPropertyChanged("Monitors");
    }
}

public Dictionary<int, string> MonitorsList
{
    get { return _monitorsList; }
}

public int StationTarget
{
    get
    {
        return _mc.StationTarget ;
    }
    set
    {
        if (_mc.StationTarget == value)
            return;
        _mc.StationTarget = value;
        SetMonitorsList();
        SetStatus();
        OnPropertyChanged("StationTarget");
        OnPropertyChanged("MonitorsList");
    }
}

private void SetStationList()
{
    _stationsList.Add(0,"OFF");
    foreach (StationViewModel station in Stations)
        _stationsList.Add( Convert.ToInt32(station.SerialCode),station.StationName);
}

private void SetMonitorsList()
{
     _monitorsList.Clear();
     _monitorsList.Add(0, "OFF");
     _filterdMonitors.Clear();
     _filterdMonitors = _monitors.Where(x => x.StationSerial == StationTarget).ToObservableCollection<MonitorViewModel>();

     foreach (MonitorViewModel monitor in _filterdMonitors)
         _monitorsList.Add(Convert.ToInt32(monitor.Channel), monitor.MonitorName);
}

我的2个来源是Dictionary<int,string> ...

如果我不单击(单击而不更改所选项目，只需单击)组合框，则源列表很好。我单击它的那一刻，列表完全没有改变。

最佳答案

很好的问题是，您绑定(bind)了Dictionary<int, string>，它没有机制将更改通知给 View 。该 View 无法识别，它必须进行更新。

因此，我想，如果您要像这样更改XAML，那么之后更改SetMonitorsList()可能会起作用。它应该修改Monitors的内容。

<ComboBox Grid.Column="1" ItemsSource="{Binding Stations}" DisplayMemberPath="Value"
          SelectedValuePath="Key" SelectedValue="{Binding Path=StationTarget, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
<ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding Monitors}"
          DisplayMemberPath="Value" SelectedValuePath="Key" SelectedValue="{Binding Path=MonitorTarget, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

关于wpf - WPF，MVVM使用另一个组合框选择项填充组合框，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/16895852/