Wpf MVVM在DataGrid中选择/取消选择项目

时间:2018-03-06 09:31:51

标签: c# wpf mvvm

我正在开发一个MVVM项目,我在其中一个视图中有这个代码:

<GroupBox   Header="Defaut"  BorderBrush="#FF4EA8DE" FontSize="16" Foreground="#FF436EFF"  >
                    <DataGrid Background="Transparent" FontSize="14" CanUserAddRows="False" CanUserDeleteRows="False" IsReadOnly="True" AutoGenerateColumns="False" Style="{x:Null}" 
                              ItemsSource="{Binding ErrorList}">
                        <DataGrid.Columns>
                            <DataGridTextColumn Width="0.5*" Header="{DynamicResource Numéro Cordon}" Binding="{Binding BeadName}"></DataGridTextColumn>
                            <DataGridTextColumn Width="0.5*" Header="{DynamicResource Indice Image}" Binding="{Binding IndiceImage}"></DataGridTextColumn>
                            <DataGridTextColumn Width="0.5*" Header="{DynamicResource Défaut}" Binding="{Binding DispDefault}"></DataGridTextColumn>
                            <DataGridTemplateColumn Header="{DynamicResource Criticité}" Width="0.5*">
                                <DataGridTemplateColumn.CellTemplate>
                                    <DataTemplate>
                                        <Label Content="{Binding IsError, Converter={StaticResource IsErrorToCriticityLevel}, Mode=OneWay}"></Label>
                                    </DataTemplate>
                                </DataGridTemplateColumn.CellTemplate>
                            </DataGridTemplateColumn>

                        </DataGrid.Columns>

                        <DataGrid.CellStyle>
                            <Style TargetType="DataGridCell">
                                <Setter Property="CmdB:CommandBehavior.Event" Value="MouseDown" />
                                <Setter Property="CmdB:CommandBehavior.Command" Value="{Binding DataContext.RobotErrorSelectionChangedCommand, 
                                                                                                RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type controls:MetroWindow}}}"/>
                                <Setter Property="CmdB:CommandBehavior.CommandParameter" Value="{Binding Path=SelectedItem, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=DataGrid}}"/>
                                <Style.Triggers>
                                    <Trigger Property="IsSelected" Value="true">
                                        <Setter Property="BorderBrush" Value="#FF6593CF" />
                                        <Setter Property="Background" Value="#FF6593CF" />
                                    </Trigger>
                                </Style.Triggers>
                            </Style>
                        </DataGrid.CellStyle>

                        <i:Interaction.Triggers>
                            <i:EventTrigger EventName="SelectionChanged">
                                <i:InvokeCommandAction Command="{Binding RobotErrorSelectionChangedCommand}" CommandParameter="{Binding Path=SelectedItem, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=DataGrid}}" />
                            </i:EventTrigger>
                        </i:Interaction.Triggers>
                    </DataGrid>
                </GroupBox>

我想要做的是能够取消选择此列表中的所选项目,但我无法找到如何访问它。

以下是与此列表相关的ViewModel中的代码:

ObservableCollection<Erreur> _ErrorList;
    public ObservableCollection<Erreur> ErrorList
    {
        get { return _ErrorList; }
        set { _ErrorList = value; RaisePropertyChanged("ErrorList");}
    }


private RelayCommand<Erreur> _RobotErrorSelectionChangedCommand;
    public RelayCommand<Erreur> RobotErrorSelectionChangedCommand
    {
        get
        {
            return _RobotErrorSelectionChangedCommand
                ?? (_RobotErrorSelectionChangedCommand = new RelayCommand<Erreur>(
                (Erreur err) =>
                {
                    if (err != null)
                    {
                        viewservice.OpenDialog(new ErreurImageViewModel(err), ServiceLocator.Current.GetInstance<MainViewModel>());

                    }     
                }));
        }
    }

感谢您提供任何帮助或建议。

3 个答案:

答案 0 :(得分:4)

您可以将Datagrid中的SelectedItem属性绑定到VM中的属性,并清除当前选择,您可以将属性设置为:null。这样,您可以随时通过代码取消选择SelectedItem

您可以在视图中将其绑定到这样:

<DataGrid ItemsSource="{Binding ErrorList}" SelectedItem="{Binding SelectedError}" ...>

然后在ViewModel中添加:

    private Erreur _selectedError = null;

    public Erreur SelectedError
    {
        get => _selectedError;
        set
        {
            if (_selectedError == value) return;
            _selectedError = value;
            RaisePropertyChanged(nameof(SelectedError));
        }
    }

每当您想要清除选择时,您可以这样做:

SelectedError = null;

如果你想从代码中选择一个特定的实例,你可以这样做:

SelectedError = myInstanceOfError;

答案 1 :(得分:0)

SelectedError属性绑定到XAML中的SelectedItem属性。

XAML:

<DataGrid Background="Transparent" FontSize="14" CanUserAddRows="False" CanUserDeleteRows="False" IsReadOnly="True" AutoGenerateColumns="False" Style="{x:Null}" ItemsSource="{Binding ErrorList}" SelectedItem="{Binding SelectedError}">

C#属性:

private Erreur _SelectedError;
public Erreur SelectedError
{
    get { return _SelectedError; }
    set {
            if(_SelectedError != value)
            {
                 _SelectedErrorList = value; 
                 RaisePropertyChanged("SelectedError");
            }
        }
}

答案 2 :(得分:0)

谢谢,两个答案都是正确的,稍加修改,我添加了:

SelectedItem="{Binding SelectedError}"  in the XAML code.

我必须对此部分进行评论以禁用该命令:

<i:Interaction.Triggers>
    <i:EventTrigger EventName="SelectionChanged">
        <i:InvokeCommandAction Command="{Binding RobotErrorSelectionChangedCommand}" CommandParameter="{Binding Path=SelectedItem, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=DataGrid}}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

现在SelectedError获取Selected Item.Thanx