при нажатии dataGridview column Изменение видимости текстового поля в WPF-MVVM?

Question

Я хочу сделать текстовое поле Visible при нажатии столбца DataGrid. Я использую это текстовое поле для описания столбца данных Сетки

Моих два столбца имеет вид сетки (пункт и столбцы Суммы)

<DataGrid>   
    <DataGrid.Columns>  
     <DataGridTemplateColumn Header="Item" Width="*"> 
      <DataGridTemplateColumn.CellTemplate> 
       <TextBlock Text="{Binding Item}" VerticalAlignment="Center"/> 
      </DataGridTemplateColumn.CellTemplate> 
     </DataGridTemplateColumn> 
    </DataGrid.Columns> 
    <DataGrid.Columns> 
     <DataGridTemplateColumn Header="Amount" Width="*"> 
      <DataGridTemplateColumn.CellTemplate> 
       <TextBlock Text="{Binding Amount}" VerticalAlignment="Center"/> 
      </DataGridTemplateColumn.CellTemplate> 
     </DataGridTemplateColumn> 
    </DataGrid.Columns> 
</DataGrid> 

Я хочу получить сумму колонке [Amount] и показать его на текстовом поле, что видно только тогда, когда я нажимаю [Amount] Колонка

Answer 1

Пожалуйста, попробуйте следующий код: 1. Xaml:

<Window x:Class="DataGridSoHelpAttempt.MainWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:dataGridSoHelpAttempt="clr-namespace:DataGridSoHelpAttempt" 
    xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" 
    Title="MainWindow" Height="350" Width="525" x:Name="This"> 
<Window.DataContext> 
    <dataGridSoHelpAttempt:MainViewModel/> 
</Window.DataContext> 
<Grid x:Name="MyGrid"> 
    <DataGrid x:Name="MyDataGrid" ItemsSource="{Binding DataSource}" AutoGenerateColumns="False"> 
     <i:Interaction.Behaviors> 
      <dataGridSoHelpAttempt:ColumnSelectingBehavior TotalPresenterVisibility="{Binding TotalsVisibility, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/> 
     </i:Interaction.Behaviors> 
     <DataGrid.Columns> 
      <DataGridTextColumn Header="Name" Binding="{Binding Name}"/> 
      <DataGridTextColumn Header="Comments" Binding="{Binding Comments}" Width="150"/> 
      <DataGridTextColumn Header="Price (click to see total)" Binding="{Binding Price, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"> 
      </DataGridTextColumn> 
     </DataGrid.Columns> 
    </DataGrid> 
    <StackPanel HorizontalAlignment="Stretch" VerticalAlignment="Bottom"> 
     <TextBlock Visibility="{Binding TotalsVisibility, UpdateSourceTrigger=PropertyChanged}"> 
      <Run Text="Total price:"></Run> 
      <Run Text="{Binding TotalValue, UpdateSourceTrigger=PropertyChanged, Mode=OneWay}"></Run> 
     </TextBlock> 
    </StackPanel> 
</Grid></Window> 

2. Просмотр и модели Код:

public class MainViewModel:BaseObservableObject 
{ 
    private Visibility _visibility; 
    private ICommand _command; 
    private Visibility _totalsVisibility; 
    private double _totalValue; 

    public MainViewModel() 
    { 
     Visibility = Visibility.Collapsed; 
     TotalsVisibility = Visibility.Collapsed; 
     DataSource = new ObservableCollection<BaseData>(new List<BaseData> 
     { 
      new BaseData {Name = "Uncle Vania", Description = "A.Chekhov, play", Comments = "worth reading", Price = 25}, 
      new BaseData {Name = "Anna Karenine", Description = "L.Tolstoy, roman", Comments = "worth reading", Price = 35}, 
      new BaseData {Name = "The Master and Margarita", Description = "M.Bulgakov, novel", Comments = "worth reading", Price = 56}, 
     }); 
    } 

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

    private void VisibilityChangingCommand() 
    { 
     Visibility = Visibility == Visibility.Collapsed ? Visibility.Visible : Visibility.Collapsed; 
    } 

    public ObservableCollection<BaseData> DataSource { get; set; } 

    public Visibility Visibility 
    { 
     get { return _visibility; } 
     set 
     { 
      _visibility = value; 
      OnPropertyChanged(); 
     } 
    } 

    public ObservableCollection<BaseData> ColumnCollection 
    { 
     get { return DataSource; } 
    } 

    public Visibility TotalsVisibility 
    { 
     get { return _totalsVisibility; } 
     set 
     { 
      _totalsVisibility = value; 
      OnPropertyChanged(); 
     } 
    } 

    public double TotalValue 
    { 
     get { return ColumnCollection.Sum(x => x.Price); } 
    } 

} 

public class BaseData:BaseObservableObject 
{ 
    private string _name; 
    private string _description; 
    private string _comments; 
    private int _price; 

    public virtual string Name 
    { 
     get { return _name; } 
     set 
     { 
      _name = value; 
      OnPropertyChanged(); 
     } 
    } 

    public virtual object Description 
    { 
     get { return _description; } 
     set 
     { 
      _description = (string) value; 
      OnPropertyChanged(); 
     } 
    } 

    public string Comments 
    { 
     get { return _comments; } 
     set 
     { 
      _comments = value; 
      OnPropertyChanged(); 
     } 
    } 

    public int Price 
    { 
     get { return _price; } 
     set 
     { 
      _price = value; 
      OnPropertyChanged(); 
     } 
    } 
} 

3. Код Поведение:

public class ColumnSelectingBehavior : Behavior<DataGrid> 
{ 
    public static readonly DependencyProperty TotalPresenterVisibilityProperty = DependencyProperty.Register(
     "TotalPresenterVisibility", typeof (Visibility), typeof (ColumnSelectingBehavior), new PropertyMetadata(Visibility.Collapsed)); 

    public Visibility TotalPresenterVisibility 
    { 
     get { return (Visibility) GetValue(TotalPresenterVisibilityProperty); } 
     set { SetValue(TotalPresenterVisibilityProperty, value); } 
    } 

    protected override void OnAttached() 
    { 
     base.OnAttached(); 
     AssociatedObject.Sorting += AssociatedObjectOnSorting; 
    } 

    private void AssociatedObjectOnSorting(object sender, DataGridSortingEventArgs dataGridSortingEventArgs) 
    { 
     var columnSortMemberPath = dataGridSortingEventArgs.Column.SortMemberPath; 
     if(columnSortMemberPath != "Price") 
      return; 
     TotalPresenterVisibility = TotalPresenterVisibility == Visibility.Visible 
      ? Visibility.Collapsed 
      : Visibility.Visible; 
    } 


    protected override void OnDetaching() 
    { 
     base.OnDetaching(); 
     AssociatedObject.Sorting -= AssociatedObjectOnSorting; 
    } 
} 

4. BaseObservableObject код (для .net 4.5):

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; 
    } 
} 

Я буду рад чтобы помочь вам в случае возникновения проблем с кодом. С уважением.