Question

我正在使用Listview将datasource作为observablecollection <empclass>

我的整体课程结构类似于

Class empclass
{ 
 command = new RelayCommand(myfunction, true);

 private int _abc;
 public int abc
  {
    get { return _abc;}
    set { _abc = value;
    onpropertychanged("abc")
   }

 private int _pqr;
 public int pqr
  {
    get { return _pqr;}
    set { _pqr = value;
    onpropertychanged("pqr")
  }



 public void myfunction()
 {
   messagebox.show((abc+pqr).Tostring());
 }
}

我有一个单独的按钮，点击该按钮我想调用所选项目的命令，以显示该对象中存在的受尊重值的abc和pqr的添加。

如果您可以通过小代码示例帮助我，那将会很棒。

由于 Ashpak

Answer 1

我假设你有一个名为ListView的{{1}}：

lv

然后，您可以绑定到<ListView Name="lv" ... </ListView>的{{1}}并使用该项SelectedItem属性。

ListView

请注意，要使其工作，您必须拥有command命令，例如：

<Button Command="{Binding ElementName=lv, Path=SelectedItem.command}">Button Text</Button>

Answer 2

试试这个： 1. XAML代码：

<Window x:Class="SoButtonBindingHelpAttempt.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:soButtonBindingHelpAttempt="clr-namespace:SoButtonBindingHelpAttempt"
    Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
    <soButtonBindingHelpAttempt:MainViewModel/>
</Window.DataContext>
<Grid>
    <ListBox ItemsSource="{Binding ObservableCollection}">
        <ListBox.ItemContainerStyle>
            <Style TargetType="ListBoxItem">
                <Setter Property="ContentTemplate">
                    <Setter.Value>
                        <DataTemplate DataType="{x:Type soButtonBindingHelpAttempt:Empclass}">
                            <Grid>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="120"></ColumnDefinition>
                                    <ColumnDefinition Width="120"></ColumnDefinition>
                                    <ColumnDefinition Width="120"></ColumnDefinition>
                                </Grid.ColumnDefinitions>
                                <TextBlock Grid.Column="0" Text="{Binding abc, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"></TextBlock>
                                <TextBlock Grid.Column="1"  Text="{Binding pqr, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"></TextBlock>
                                <Button    Grid.Column="2"  Command="{Binding Command}" Content="Press me!"></Button>
                            </Grid>
                        </DataTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </ListBox.ItemContainerStyle>
    </ListBox>
</Grid></Window>

2。 ViewModel代码型号代码：

    public class MainViewModel:BaseObservableObject
{
    public MainViewModel()
    {
        ObservableCollection = new ObservableCollection<Empclass>(new List<Empclass>
        {
            new Empclass{abc=2, pqr = 3},
            new Empclass{abc=5, pqr = 7},
            new Empclass{abc=11, pqr = 13},
            new Empclass{abc=17, pqr = 19}
        });
    }
    public ObservableCollection<Empclass> ObservableCollection { get; set; }
}

public class Empclass : BaseObservableObject
{
    private ICommand _command;
    private int _abc;
    private int _pqr;

    public ICommand Command
    {
        get { return _command ?? (_command = new RelayCommand(myfunction)); }
    }

    public int abc
    {
        get { return _abc; }
        set
        {
            _abc = value;
            OnPropertyChanged("abc");
        }
    }


    public int pqr
    {
        get { return _pqr; }
        set
        {
            _pqr = value;
            OnPropertyChanged("pqr");
        }
    }


    private void myfunction()
    {
        //add you command logic here
        var temp = pqr;
        pqr = abc;
        abc = temp;
    }
}

3。 MVVM部件实现：

    public class BaseObservableObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        var handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }

    protected virtual void OnPropertyChanged<T>(Expression<Func<T>> raiser)
    {
        var propName = ((MemberExpression)raiser.Body).Member.Name;
        OnPropertyChanged(propName);
    }

    protected bool Set<T>(ref T field, T value, [CallerMemberName] string name = null)
    {
        if (!EqualityComparer<T>.Default.Equals(field, value))
        {
            field = value;
            OnPropertyChanged(name);
            return true;
        }
        return false;
    }
}

public class RelayCommand<T> : ICommand
{
    readonly Action<T> _execute;
    readonly Func<T, bool> _canExecute;

    public event EventHandler CanExecuteChanged;

    public RelayCommand(Action<T> execute, Func<T, bool> canExecute = null)
    {
        _execute = execute;
        _canExecute = canExecute;
    }

    public void RefreshCommand()
    {
        var cec = CanExecuteChanged;
        if (cec != null)
            cec(this, EventArgs.Empty);
    }

    public bool CanExecute(object parameter)
    {
        if (_canExecute == null) return true;
        return _canExecute((T)parameter);
    }

    public void Execute(object parameter)
    {
        _execute((T)parameter);
    }
}

public class RelayCommand : RelayCommand<object>
{
    public RelayCommand(Action execute, Func<bool> canExecute = null)
        : base(_ => execute(),
            _ => canExecute == null || canExecute())
    {

    }
}

4。如下所示：

此致

WPF绑定observablecollection中选定项的命令属性

2 个答案: