我有一个datagrid，里面有两个组合框列。第一个组合框是PersonnelTypes列表。根据选择的PersonnelType，第二个组合框应填充与所选PersonnelType匹配的资源列表
问题是，假设我有两行数据，如果我更改一行的PersonnelType，datagrid将为每一行中的所有资源设置itemsource。我只希望它过滤我所在的行，而不是所有行。
这是包含组合框的数据网格部分的xaml：
<DataGridTemplateColumn Header="Personnel Type" Width="Auto">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<ComboBox Name="cmbPersonnelTypes" FontWeight="Bold" ItemsSource="{Binding ViewModel.PersonnelTypes, RelativeSource={RelativeSource AncestorType=Window}}" SelectedItem="{Binding PersonnelType, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" SelectedValuePath="ID" DisplayMemberPath="Description" SelectionChanged="cmbPersonnelTypes_SelectionChanged" />
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Name" Width="Auto">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<ComboBox Name="cmbPersonnelName" FontWeight="Bold" ItemsSource="{Binding ViewModel.ResourcesToChooseFrom, RelativeSource={RelativeSource AncestorType=Window},UpdateSourceTrigger=PropertyChanged}" SelectedItem="{Binding Resource, Mode=TwoWay}" SelectedValuePath="Refno" DisplayMemberPath="Name" />
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
以下是整个数据网格的xaml（以防需要查看）：
<DataGrid AutoGenerateColumns="False" CanUserSortColumns="False" CanUserDeleteRows="True" IsReadOnly="True" Background="LightGray" CanUserAddRows="False" Margin="5" SelectedItem="{Binding SelectedLA_JobPersonnel}" ItemsSource="{Binding LA_Personnel}" Grid.ColumnSpan="4" MouseDoubleClick="DataGrid_MouseDoubleClick_1">
<DataGrid.Resources>
<ViewModels:BindingProxy x:Key="proxy" Data="{Binding}" />
</DataGrid.Resources>
<DataGrid.Columns>
<DataGridTemplateColumn Header="Personnel Type" Width="Auto">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<ComboBox Name="cmbPersonnelTypes" FontWeight="Bold" ItemsSource="{Binding ViewModel.PersonnelTypes, RelativeSource={RelativeSource AncestorType=Window}}" SelectedItem="{Binding PersonnelType, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" SelectedValuePath="ID" DisplayMemberPath="Description" SelectionChanged="cmbPersonnelTypes_SelectionChanged" />
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Name" Width="Auto">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid>
<ComboBox Name="cmbPersonnelName" FontWeight="Bold" ItemsSource="{Binding ViewModel.ResourcesToChooseFrom, RelativeSource={RelativeSource AncestorType=Window},UpdateSourceTrigger=PropertyChanged}" SelectedItem="{Binding Resource, Mode=TwoWay}" SelectedValuePath="Refno" DisplayMemberPath="Name" />
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn> <DataGridTemplateColumn Header="Date Out" Width="20*" >
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Background="LightGray" FontWeight="Bold" Text="{Binding DateOut, Mode=TwoWay, Converter={StaticResource thisNullDateConverter}, StringFormat={}{0:MMM-dd-yyyy hh:ss tt}}">
</TextBlock>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<Toolkit:DateTimePicker Background="LightGray" FontWeight="Bold" Value="{Binding Path=DateOut, Mode=TwoWay, Converter={StaticResource thisNullDateConverter}}" Format="Custom" FormatString="MMM dd yyyy hh:ss tt"></Toolkit:DateTimePicker>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Date In" Width="20*">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Background="LightGray" FontWeight="Bold" Text="{Binding DateIn, Mode=TwoWay, Converter={StaticResource thisNullDateConverter}, StringFormat={}{0:MMM-dd-yyyy hh:ss tt}}">
</TextBlock>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<Toolkit:DateTimePicker Background="LightGray" FontWeight="Bold" Value="{Binding Path=DateIn, Mode=TwoWay, Converter={StaticResource thisNullDateConverter}}" Format="Custom" FormatString="MMM dd yyyy hh:ss tt"></Toolkit:DateTimePicker>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
以下是xaml（xaml.cs）背后的代码：
public JobEditorViewModel ViewModel
{
get { return viewModel; }
}
private void cmbPersonnelTypes_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var combobox = sender as ComboBox;
if (combobox != null)
{
var selectedPersonnelType = combobox.SelectedItem as PersonnelType;
viewModel.SetResourcesToChooseFrom(selectedPersonnelType);
}
}
以下是viewModel中的代码：
public BindingList<PersonnelType> PersonnelTypes
{
get; set;
}
public JobEditorViewModel(int jobid, string region, DataAccessDataContext db, ServiceUserControlViewModel serviceViewModel)
{
PersonnelTypes = new BindingList<PersonnelType>(_db.PersonnelTypes.OrderBy(p => p.Head).ThenBy(p => p.Description).ToList());
}
private BindingList<Resource> _resourcesToChooseFrom;
public BindingList<Resource> ResourcesToChooseFrom
{
get { return _resourcesToChooseFrom; }
set
{
_resourcesToChooseFrom = value;
NotifyPropertyChanged("ResourcesToChooseFrom");
}
}
public void SetResourcesToChooseFrom(PersonnelType personnelType)
{
ResourcesToChooseFrom =
new BindingList<Resource>(_db.Resources.Where(r => r.Head == personnelType.Head && r.Refno > 2).OrderBy(r=>r.Name).ToList());
}
如果您需要了解更多信息，请与我们联系
答案 0 :(得分：1)
嗯，在这里工作的同事的帮助下，我们想出了我需要做的事情。多重绑定就是答案。首先，我们进行了一些黑客攻击，以便将两个组合框放在同一列中，将它们放在一个网格中并将网格放在一列中。所以现在两个组合框都可以看到彼此，因为它们位于相同的DataGridTemplateColumn中。以前，我们无法让他们看到对方，因为他们在两个独立的DataGridTemplateColumns中失去了彼此的范围。
这是我们在xaml中所做的：
<DataGridTemplateColumn Header="Personnel Type-Name" Width="Auto" >
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="170"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Border Grid.Column="0" BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding PersonnelType.Description}"/>
</Border>
<Border Grid.Column="1" BorderBrush="Black" BorderThickness="1">
<TextBlock Text="{Binding Resource.Name}"/>
</Border>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="170"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<ComboBox Name="cmbPersonnelTypes" Grid.Column="0" FontWeight="Bold" ItemsSource="{Binding ViewModel.PersonnelTypes, RelativeSource={RelativeSource AncestorType=Window}, UpdateSourceTrigger=PropertyChanged}" SelectedItem="{Binding PersonnelType, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" SelectedValuePath="ID" DisplayMemberPath="Description" />
<ComboBox Name="cmbPersonnelName" Grid.Column="1" FontWeight="Bold" SelectedItem="{Binding Resource, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" SelectedValuePath="Refno" DisplayMemberPath="Name" >
<ComboBox.ItemsSource>
<MultiBinding Converter="{StaticResource FilteredPersonnelConverter}">
<Binding Path="ViewModel.AvailablePersonnel" RelativeSource="{RelativeSource AncestorType=Window}"/>
<Binding Path="SelectedItem" ElementName="cmbPersonnelTypes"/>
<Binding Path="ViewModel.SelectedGlobalResourceViewOption" RelativeSource="{RelativeSource AncestorType=Window}"/>
</MultiBinding>
</ComboBox.ItemsSource>
</ComboBox>
</Grid>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
你会注意到MultiBinding中有一个名为FilteredPersonnelConverter的ValueConverter。这个值转换器为我做了所有过滤。这是代码：
public class FilteredPersonnelListValueConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
var allResources = values[0] as IList<Resource>;
var personnelType = values[1] as PersonnelType;
var selectedGlobalResourceView = values[2] as ResourceViewOption;
if (personnelType == null)
return allResources;
if(selectedGlobalResourceView.ResourceViewTitle=="Regional")
return allResources.Where(r => r.Head == personnelType.Head && r.Obsolete == false && r.Location.Region.RegionID.Trim()==SettingsManager.OpsMgrSettings.Region.Trim()).OrderBy(r => r.Name).ToList();
if (selectedGlobalResourceView.ResourceViewTitle == "Local")
return allResources.Where(r => r.Head == personnelType.Head && r.Obsolete == false && r.LocnID.Trim() == SettingsManager.OpsMgrSettings.LOCNCODE.Trim()).OrderBy(r => r.Name).ToList();
return allResources.Where(r => r.Head == personnelType.Head &&r.Obsolete==false).OrderBy(r => r.Name).ToList();
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
因此，如果其他人正在做这样的事情，请查看Multibinding，它会改变你的生活
答案 1 :(得分：0)
当用户更改视图中的PersonelType下拉列表时，ViewModel应该过滤资源列表（应该使用正确的信息更新第二个下拉框）。
实际上，您的视图模型只需要设置为响应视图上的更改。这就是它归结为。
看这里：
public JobEditorViewModel(int jobid, string region, DataAccessDataContext db, ServiceUserControlViewModel serviceViewModel)
{
PersonnelTypes = new BindingList<PersonnelType>(_db.PersonnelTypes.OrderBy(p => p.Head).ThenBy(p => p.Description).ToList());
}
看起来您在构造函数中设置了personel类型，但您没有响应用户更改。您需要在视图模型中的PersonelType绑定中执行此操作。
修改
我现在看到你正在处理改变的选择。但实际上我认为这应该在视图模型本身中完成。特别是因为您实际上从视图中访问了viewmodel以进行更改。
示例
所以这是我的VM：
class ViewModel : INotifyPropertyChanged
{
DispatcherTimer timer = new DispatcherTimer();
public ViewModel()
{
// Create my observable collection
this.DateTimes = new ObservableCollection<DateTime>();
// Every second add anothe ritem
timer.Interval = TimeSpan.FromSeconds(1);
timer.Tick += new EventHandler(timer_Tick);
timer.Start();
}
void timer_Tick(object sender, EventArgs e)
{
// This adds to the collection
this.DateTimes.Add(DateTime.Now);
}
public ObservableCollection<DateTime> DateTimes { get; private set; }
public event PropertyChangedEventHandler PropertyChanged;
}
和我的观点：
<ListBox ItemsSource="{Binding DateTimes}"/>
请注意，我不重建集合。我只需设置一次，然后根据需要更改它的大小。