wpf - 导致属性触发切换复选框 WPF DataGrid

Question

如何获得属性更改以注册复选框切换？我希望我的保存按钮在复选框被切换但无法触发属性更改时启用，因此我可以调用 RaiseCanExecuteChanged。我的复选框在 DataGrid 中。 IsGeneric 是 ProgramsSelected 的一个属性，我将该属性添加到我的 View 模型中以查看是否有帮助，但它没有。

XAML

<DataGrid ItemsSource="{Binding Programs}"
          SelectedItem="{Binding ProgramSelected}"
    <DataGrid.Columns>
         <DataGridCheckBoxColumn Binding="{Binding IsGenericView, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Header="Is Generic" />
    </DataGrid.Columns>
</DataGrid>

<Button Command="{Binding SaveProgramsCommand}" Content="Save Programs" />

节目类

namespace OPP.Models
{
    using SimpleMvvmToolkit;

    public class Program : ModelBase<Program>
    {
        private bool isGenericView;

        public string Name { get; set; }

        public string Value { get; set; }

        public bool IsGenericView
        {
            get
            {
                return this.isGenericView;
            }

            set
            {
                this.isGenericView = value;

                this.NotifyPropertyChanged(m => m.IsGenericView);
            }
        }

        public bool ShowAtTop { get; set; }
    }
}

View 模型

public class ManageProgramsViewModel : ViewModelDetailBase<ManageProgramsViewModel, Program>
{
    public ICommand SaveProgramsCommand
    {
    get
    {
        return this.saveProgramsDelegate
            ?? (this.saveProgramsDelegate = Helpers.DelegateCommandFactory.CreateCommand(this.SavePrograms, this.CheckCanSavePrograms));
    }
    }
}

public ObservableCollection<Program> Programs
{
    get
    {
        return this.Programs;
    }

    private set
    {
        this.programs = value;

        this.NotifyPropertyChanged(m => m.Programs);
    }
}

public Program ProgramSelected
{
    get
    {
        return this.programSelected;
    }

    private set
    {
        this.programSelected = value;

        this.NotifyPropertyChanged(m => m.ProgramSelected);
    }
}

public bool IsGenericView       // Never hits the breakpoint when I check or uncheck my checkbox
{
    get
    {
        return this.isGenericView;
    }

    set
    {
        this.isGenericView = value;

        this.NotifyPropertyChanged(m => m.IsGenericView);

        this.CanSavePrograms = !this.CanSavePrograms;
    }
}

public bool CanSavePrograms
{
    get
    {
        return this.canSavePrograms;
    }

    set
    {
        this.canSavePrograms = value;

        Helpers.DelegateCommandFactory.RaiseCanExecuteChanged(this.SaveProgramsCommand);
    }
}

Answer 1

在 XAML 中，您应该使用 DataTrigger :

...
<Button Command="{Binding SaveProgramsCommand}" Content="Save Programs" >
    <Button.Style>
        <Style TargetType="Button">
            <Setter Property="IsEnabled" Value="False" />
            <Setter Property="Opacity" Value=".5" />
            <Style.Triggers>
                <DataTrigger Binding="{Binding ProgramSelected.IsGenericView}" Value="True">
                    <Setter Property="IsEnabled" Value="True" />
                    <Setter Property="Opacity" Value="1" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>   
...

类(class) Program应该实现接口(interface) INotifyPropertyChanged :

public class Program : INotifyPropertyChanged
{
    private bool _isGenericView;
    public string Name { get; set; }

    public string Value { get; set; }

    public bool IsGenericView
    {
        get { return _isGenericView; }
        set
        {
            _isGenericView = value;
            OnPropertyChanged("IsGenericView");
        }
    }

    public bool ShowAtTop { get; set; }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
}

你的 ViewModel 也应该实现接口(interface) INotifyPropertyChanged :

...
public Program ProgramSelected
{
    get
    {
        return this.programSelected;
    }
    set
    {
        this.programSelected = value;
        OnPropertyChanged("ProgramSelected");
    }
}
...