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Make (create) reusable dynamic Views

Out team wants to create reusable, stylable Views. For example, we want to reuse in different apps the CommonPromptView (our own, customizable dialog box where we can hide "Cancel" button, set the header, show specific icon and so on).

That view has several elements on it's surface: TextBlocks, Buttons. We want to make them stylable to.

Well, what is the best approach to solve this task?

  1. The view can be of type Window.
  2. The view can be of type UserControl.

In the first case, styling can be supported in two ways:

  1. Styles of elements have references to DynamicResources.
  2. Styles are passed in to the constructor of a View.

The both are not clean (in my opinion).

But if a View is a UserControl, then each time somebody who creates new app has to create a new Window to contain a UserControl and set it's bindings to DPs (of Style type) properly. Besides, if a UserControl has it's own very convinient API (static methods for the most frequently used operations) which will be lost for the user of the Window which contains the UserControl.

Update

Example of CommonPromptView implemented as a UserControl.

Code-behind

 public sealed partial class CommonPromptView {
    private const int CloseViewTimeIntervalInMilliseconds = 120000;
    private DispatcherTimer timer;

    public static readonly DependencyProperty CommonPromptBorderStyleProperty = DependencyProperty.Register(
        "CommonPromptBorderStyle", typeof (Style), typeof (CommonPromptView), new PropertyMetadata(default(Style)));

    public Style CommonPromptBorderStyle {
        get { return (Style) GetValue(CommonPromptBorderStyleProperty); }
        set { SetValue(CommonPromptBorderStyleProperty, value); }
    }

    public static readonly DependencyProperty CommonPromptHeaderStyleProperty = DependencyProperty.Register(
        "CommonPromptHeaderStyle", typeof (Style), typeof (CommonPromptView), new PropertyMetadata(default(Style)));

    public Style CommonPromptHeaderStyle {
        get { return (Style) GetValue(CommonPromptHeaderStyleProperty); }
        set { SetValue(CommonPromptHeaderStyleProperty, value); }
    }

    public static readonly DependencyProperty CommonPromptMessageStyleProperty = DependencyProperty.Register(
        "CommonPromptMessageStyle", typeof (Style), typeof (CommonPromptView), new PropertyMetadata(default(Style)));

    public Style CommonPromptMessageStyle {
        get { return (Style) GetValue(CommonPromptMessageStyleProperty); }
        set { SetValue(CommonPromptMessageStyleProperty, value); }
    }

    public static readonly DependencyProperty CommonPromptSpitterStyleProperty = DependencyProperty.Register(
        "CommonPromptSpitterStyle", typeof (Style), typeof (CommonPromptView), new PropertyMetadata(default(Style)));

    public Style CommonPromptSpitterStyle {
        get { return (Style) GetValue(CommonPromptSpitterStyleProperty); }
        set { SetValue(CommonPromptSpitterStyleProperty, value); }
    }

    public static readonly DependencyProperty CommonPromptButtonStyleProperty = DependencyProperty.Register(
        "CommonPromptButtonStyle", typeof (Style), typeof (CommonPromptView), new PropertyMetadata(default(Style)));

    public Style CommonPromptButtonStyle {
        get { return (Style) GetValue(CommonPromptButtonStyleProperty); }
        set { SetValue(CommonPromptButtonStyleProperty, value); }
    }

    [SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public CommonPromptView(object header = null, string message = "Вы действительно хотите продолжить?",
        Visibility headerVisibility = Visibility.Collapsed,
        MessageBoxIconWPF iconType = MessageBoxIconWPF.Question,
        object affirmButtonContent = null, object cancelButtonContent = null,
        Visibility cancelButtonVisibility = Visibility.Visible, Visibility affirmButtonVisibility = Visibility.Visible) {
        InitializeComponent();
        Header.Content = header ?? string.Empty;
        if (header == null)
            HeaderSplitter.Visibility = Visibility.Collapsed;
        Message.Content = message;

        Ok.Content = affirmButtonContent ?? "ОК";
        Cancel.Content = cancelButtonContent ?? "Отмена";

        Cancel.Visibility = cancelButtonVisibility;
        Header.Visibility = headerVisibility;
        Ok.Visibility = affirmButtonVisibility;

        BitmapImage icon = new BitmapImage();
        icon.BeginInit();
        icon.UriSource = new Uri(GetIconPath(iconType));
        //new Uri("pack://application:,,,/ApplicationName;component/Resources/logo.png");
        icon.EndInit();

        Icon.Source = icon;

        SetTimer();
    }

    private static string GetIconPath(MessageBoxIconWPF icon) {
        const string uri = "pack://application:,,,/Microtech.WPF.Common;component/";
        string iconName;
        switch (icon) {
            case MessageBoxIconWPF.Error:
                iconName = "CustomDialogStop";
                break;
            case MessageBoxIconWPF.Information:
                iconName = "CustomDialogInformation";
                break;
            case MessageBoxIconWPF.Question:
                iconName = "CustomDialogQuestion";
                break;
            case MessageBoxIconWPF.Warning:
                iconName = "CustomDialogWarning";
                break;
            default:
                throw new ArgumentException("There were no such an image");
        }
        return uri + string.Format("Images/{0}.{1}", iconName, "png");
    }

    public CommonPromptView(string content, Visibility cancelButtonVisibility = Visibility.Visible)
        : this(message: content, cancelButtonVisibility: cancelButtonVisibility) {
    }

    private void SetTimer() {
        TimeSpan timerInterval = TimeSpan.FromMilliseconds(CloseViewTimeIntervalInMilliseconds);
        timer = new DispatcherTimer(timerInterval, DispatcherPriority.ApplicationIdle,
            (obj, e) => Cancel_Click(null, null),
            Dispatcher.CurrentDispatcher);
        timer.Start();
    }

    public CommonPromptView() {
        InitializeComponent();
    }

    public static bool PromptOnUserAgreement(string header, string message, string okText = "Да",
        string cancelText = "Нет") {
        return new CommonPromptView(header,
            message, Visibility.Visible, MessageBoxIconWPF.Information, okText, cancelText).ShowDialog()
            .GetValueOrDefault();
    }

    public static void PromptOnWarning(string header, string message) {
        new CommonPromptView(header, message, headerVisibility: Visibility.Visible, iconType: MessageBoxIconWPF.Warning,
            cancelButtonVisibility: Visibility.Collapsed).ShowDialog();
    }

    public static void PromptOnError(string header, string message) {
        new CommonPromptView(header, message, headerVisibility: Visibility.Visible, iconType: MessageBoxIconWPF.Error,
            cancelButtonVisibility: Visibility.Collapsed).ShowDialog();
    }

    public static void PromptOnSuccess(string header, string message) {
        new CommonPromptView(header, message, headerVisibility: Visibility.Visible,
            iconType: MessageBoxIconWPF.Information,
            cancelButtonVisibility: Visibility.Collapsed).ShowDialog();
    }

    private void Ok_Click(object sender, RoutedEventArgs e) {
        StopTimer();
        TryCloseTheWindow(true);            
    }

    private void Cancel_Click(object sender, RoutedEventArgs e) {
        StopTimer();
        TryCloseTheWindow(false);
    }

    private void TryCloseTheWindow(bool dialogResult) {
        Window parentwin = GetWindow(this);
        if (parentwin != null) {
            try {
                parentwin.DialogResult = dialogResult;
            } catch (InvalidOperationException) {

            }
            parentwin.Close();
        }
    }

    private void StopTimer() {
        if (timer != null) {
            timer.Stop();
            timer = null;
        }
    }
}

XAML

<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"                  
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             x:Class="Microtech.WPF.Common.CommonPromptView"
             Background="Transparent" 
             DataContext="{Binding RelativeSource={RelativeSource Self}}">

<UserControl.Resources>
    <Style x:Key="DefaultViewStyle" TargetType="Window">
        <Setter Property="ResizeMode" Value="NoResize" />
        <Setter Property="ShowInTaskbar" Value="False" />
        <Setter Property="WindowStyle" Value="None" />
        <Setter Property="WindowState" Value="Normal" />
        <Setter Property="SizeToContent" Value="WidthAndHeight" />
        <Setter Property="Topmost" Value="True" />
        <Setter Property="Cursor" Value="Arrow" />
    </Style>

    <Style x:Key="DefaultHeaderStyle" TargetType="Label">
        <Setter Property="Margin" Value="10,5,5,5"/>
        <Setter Property="HorizontalAlignment" Value="Left" />
        <Setter Property="VerticalAlignment" Value="Center" />
        <Setter Property="FontSize" Value="20" />
        <Setter Property="FontWeight" Value="Bold" />
    </Style>

    <Style x:Key="DefaultBorderStyle" TargetType="Border">
        <Setter Property="Background" Value="#ADAAAD"/>
        <Setter Property="BorderBrush" Value="Black" />
        <Setter Property="Padding" Value="10" />
        <Setter Property="BorderThickness" Value="3"/>
        <Setter Property="CornerRadius" Value="10"/>          
    </Style>

    <Style x:Key="DefaultMessageStyle" TargetType="Label">
        <Setter Property="Margin" Value="10"/>
        <Setter Property="FontSize" Value="14"/>
        <Setter Property="FontFamily" Value="Verdana"/>
        <Setter Property="FontWeight" Value="Normal"/>
    </Style>

    <Style x:Key="DefaultSplitterStyle" TargetType="GridSplitter">
        <Setter Property="HorizontalAlignment" Value="Stretch" />
        <Setter Property="VerticalAlignment" Value="Bottom" />
        <Setter Property="BorderThickness" Value="0.65" />
        <Setter Property="BorderBrush" Value="Black" />
        <Setter Property="IsEnabled" Value="False" />
    </Style>

    <Style x:Key="FStandartButton" TargetType="{x:Type Button}">
        <Setter Property="Background" Value="{x:Null}" />
        <Setter Property="BorderBrush" Value="#00000000" />
        <Setter Property="Foreground" Value="White" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="Height" Value="Auto" />
        <Setter Property="MinHeight" Value="55" />
        <Setter Property="Width" Value="420" />
        <Setter Property="Margin" Value="5" />
        <Setter Property="Padding" Value="10" />
        <Setter Property="FontSize" Value="22" />
        <Setter Property="FontWeight" Value="Bold" />
        <Setter Property="FocusVisualStyle" Value="{x:Null}" />

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Border x:Name="border" BorderBrush="#FF000000" BorderThickness="1,1,1,1" CornerRadius="4,4,4,4">
                        <Border.Background>
                            <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
                                <GradientStop Offset="0" Color="#8C8A8C" />
                                <GradientStop Offset="1" Color="#636163" />
                            </LinearGradientBrush>
                        </Border.Background>
                        <ContentPresenter Name="ContentContainer" 
                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                          RecognizesAccessKey="True"
                          SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter TargetName="border" Property="Background" Value="#CC000000" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter Property="Foreground" Value="Gray" />
                        </Trigger>

                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <Style x:Key="DefaultButtonStyle" TargetType="Button" BasedOn="{StaticResource FStandartButton}">
        <Setter Property="FontFamily" Value="Verdana"/>
        <Setter Property="FontSize" Value="14"/>
        <Setter Property="Margin" Value="6"/>
    </Style>
</UserControl.Resources>

<Border Style="{Binding CommonPromptBorderStyle, TargetNullValue={StaticResource DefaultBorderStyle}}">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>

        <Label x:Name="Header"
               Style="{Binding CommonPromptHeaderStyle, TargetNullValue={StaticResource DefaultHeaderStyle}}" />
        <GridSplitter x:Name="HeaderSplitter" Grid.Row="0" 
                      Style="{Binding CommonPromptSpitterStyle, TargetNullValue={StaticResource DefaultSplitterStyle}}"
                      />

        <StackPanel Grid.Row="1" Margin="5,10,5,0" Orientation="Horizontal">
            <Image x:Name="Icon" Width="32" Height="32" Margin="5" 
                   HorizontalAlignment="Left"
                   VerticalAlignment="Center" />
            <Label x:Name="Message" 
                   Style="{Binding CommonPromptMessageStyle, 
                           TargetNullValue={StaticResource DefaultMessageStyle}}" />
        </StackPanel>

        <StackPanel Grid.Row="2" HorizontalAlignment="Center" Orientation="Horizontal">
            <Button x:Name="Ok" 
                    Style="{Binding CommonPromptButtonStyle, TargetNullValue={StaticResource DefaultButtonStyle}}"  
                    Click="Ok_Click" />
            <Button x:Name="Cancel" 
                    Style="{Binding CommonPromptButtonStyle, TargetNullValue={StaticResource DefaultButtonStyle}}"  
                    IsDefault="True" Click="Cancel_Click" />
        </StackPanel>
    </Grid>
</Border>

like image 816
EngineerSpock Avatar asked Dec 30 '13 11:12

EngineerSpock


1 Answers

I think in your case you need to look in the direction of DataTemplate, to make the dynamic content. I made a few examples that show this. The general meaning of this examples:

Given two buttons, one for the user and one for the administrator. If you choose the User, the content is displayed to the user, if the Admin, then for administrator.

Clearly, this is not the most realistic example, but it's just a way to show the dynamic selection of content. For you, you will determine the condition of replacement content.

Example A

This example demonstrates the dynamic replacing DataTemplates, depending on the input values​​. If we think in terms of style patterns, it is very similar to the abstract factory, where instead of classes - DataTemplate, and factory method is a dynamic DataTemplate selector. Example is fully suitable for MVVM pattern. Below is an example:

MainWindow.xaml

<Grid>
    <ContentControl Name="MainView"
                    ContentTemplate="{StaticResource MainView}">

        <ViewModels:MainViewModel />
    </ContentControl>
</Grid>

MainView.xaml

It's a DataTemplate in ResourceDictionary. There are two templates: UserTemplate and AdminTemplate. One for the user and one for the administrator. In the style of ContentControl defined ContentTemplateSelector, and a collection of templates that will be installed by the condition. In property Content for DynamicContentControl is set content string that can be: User or Admin.

<DataTemplateSelectors:DynamicTemplateSelector x:Key="MyTemplateSelector" />

<DataTemplate x:Key="UserTemplate">
    <StackPanel>
        <TextBlock Text="Content for user"
                   FontSize="20"
                   HorizontalAlignment="Center"
                   VerticalAlignment="Center" />

        <Button Content="Yes" />
        <Button Content="No" />
    </StackPanel>
</DataTemplate>

<DataTemplate x:Key="AdminTemplate">
    <StackPanel>
        <TextBlock Text="Content for admin"
                   FontSize="20"
                   HorizontalAlignment="Center"
                   VerticalAlignment="Center" />

        <TextBox Text="Whom banned?" />
        <Button Content="Ban" />
        <Button Content="AntiBan" />
    </StackPanel>
</DataTemplate>

<Style x:Key="DynamicContentStyle" TargetType="{x:Type ContentControl}">
    <Setter Property="ContentTemplateSelector" Value="{StaticResource MyTemplateSelector}" />
    <Setter Property="Width" Value="200" />
    <Setter Property="Height" Value="200" />

    <Setter Property="DataTemplateSelectors:DynamicTemplateSelector.Templates">
        <Setter.Value>
            <DataTemplateSelectors:TemplateCollection>
                <DataTemplateSelectors:Template Value="User" 
                                                DataTemplate="{StaticResource UserTemplate}" />

                <DataTemplateSelectors:Template Value="Admin" 
                                                DataTemplate="{StaticResource AdminTemplate}" />
            </DataTemplateSelectors:TemplateCollection>
        </Setter.Value>
    </Setter>
</Style>

<DataTemplate x:Key="MainView" DataType="{x:Type ViewModels:MainViewModel}">
    <Grid>
        <Button Name="UserButton"
                Content="Are you user?"
                Width="100"
                Height="30"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding UserButtonCommand}" />

        <Button Name="AdminButton"
                Content="Are you admin?"
                Width="100"
                Height="30"
                HorizontalAlignment="Right"
                VerticalAlignment="Top"
                Command="{Binding AdminButtonCommand}" />

        <ContentControl Name="DynamicContent"                            
                        Style="{StaticResource DynamicContentStyle}"
                        Content="{Binding Path=MainModel.ContentType,
                                          Mode=TwoWay,
                                          UpdateSourceTrigger=PropertyChanged}" />
    </Grid>
</DataTemplate>

MainViewModel.cs

Here in commands set the content type.

public class MainViewModel
{
    #region MainModel

    private MainModel _mainModel = null;

    public MainModel MainModel
    {
        get
        {
            return _mainModel;
        }

        set
        {
            _mainModel = value;
        }
    }

    #endregion

    #region UserButton Command

    private ICommand _userButtonCommand = null;

    public ICommand UserButtonCommand
    {
        get
        {
            if (_userButtonCommand == null)
            {
                _userButtonCommand = new RelayCommand(param => this.UserButton(), null);
            }

            return _userButtonCommand;
        }
    }

    private void UserButton() 
    {
        MainModel.ContentType = "User";
    }

    #endregion

    #region AdminButton Command

    private ICommand _adminButtonCommand = null;

    public ICommand AdminButtonCommand
    {
        get
        {
            if (_adminButtonCommand == null)
            {
                _adminButtonCommand = new RelayCommand(param => this.AdminButton(), null);
            }

            return _adminButtonCommand;
        }
    }

    private void AdminButton()
    {
        MainModel.ContentType = "Admin";
    }

    #endregion

    public MainViewModel() 
    {
        MainModel = new MainModel();
    }
}

MainModel.cs

public class MainModel : NotificationObject
{
    private string _contentType = "";

    public string ContentType
    {
        get
        {
            return _contentType;
        }

        set
        {
            _contentType = value;
            NotifyPropertyChanged("ContentType");
        }
    }
}

DynamicTemplateSelector

Taken and little reworked from CodeProject:

public class DynamicTemplateSelector : DataTemplateSelector
{
    #region Templates Dependency Property

    public static readonly DependencyProperty TemplatesProperty =
        DependencyProperty.RegisterAttached("Templates", typeof(TemplateCollection), typeof(DataTemplateSelector),
        new FrameworkPropertyMetadata(new TemplateCollection(), FrameworkPropertyMetadataOptions.Inherits));

    public static TemplateCollection GetTemplates(UIElement element)
    {
        return (TemplateCollection)element.GetValue(TemplatesProperty);
    }

    public static void SetTemplates(UIElement element, TemplateCollection collection)
    {
        element.SetValue(TemplatesProperty, collection);
    }

    #endregion

    #region SelectTemplate

    public override DataTemplate SelectTemplate(object item, DependencyObject container)
    {
        string myStringItem = (string)item;

        if (!(container is UIElement))
        {
            return base.SelectTemplate(item, container);
        }

        TemplateCollection templates = GetTemplates(container as UIElement);

        if (templates == null || templates.Count == 0)
        {
            base.SelectTemplate(item, container);
        }

        foreach (var template in templates)
        {
            if (myStringItem.Equals(template.Value.ToString()))
            {
                return template.DataTemplate;
            }
        }

        return base.SelectTemplate(item, container);
    }

    #endregion
}

#region TemplateCollection

public class TemplateCollection : List<Template>
{

}

#endregion

#region Template Dependency Object

public class Template : DependencyObject
{
    public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("Value", typeof(string), typeof(Template));

    public static readonly DependencyProperty DataTemplateProperty =
       DependencyProperty.Register("DataTemplate", typeof(DataTemplate), typeof(Template));

    public string Value
    { get { return (string)GetValue(ValueProperty); } set { SetValue(ValueProperty, value); } }

    public DataTemplate DataTemplate
    { get { return (DataTemplate)GetValue(DataTemplateProperty); } set { SetValue(DataTemplateProperty, value); } }
}

#endregion

Result for User

Result for user

Result for Admin

Result for admin

Notes about this way

Advantages:

  • full independence from different View

Disadvantages:

  • need to create a separate data template (View), in some cases ViewModel, for each condition.

Conclusion:

This method is suitable for completely different views, if the representations are not much different, you see a second example.

Example B

This example uses a one DataTemplate, the data is taken from the model, by default, all controls are hidden (Visibility.Collapsed), all actions in View are performed via DataTriggers. Example is fully suitable for MVVM pattern.

MainWindow.xaml

<Grid>
    <ContentControl Name="MainView"
                    ContentTemplate="{StaticResource MainView}">

        <ViewModels:MainViewModel />
    </ContentControl>
</Grid>

MainView.xaml

<DataTemplate x:Key="MainView" DataType="{x:Type ViewModels:MainViewModel}">
    <Grid>
        <Button Name="UserButton"
                Content="Are you user?"
                Width="100"
                Height="30"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding UserButtonCommand}" />

        <Button Name="AdminButton"
                Content="Are you admin?"
                Width="100"
                Height="30"
                HorizontalAlignment="Right"
                VerticalAlignment="Top"
                Command="{Binding AdminButtonCommand}" />

        <StackPanel Name="MainViewPanel"
                    Tag="{Binding Path=MainModel.ContentType,
                                  Mode=TwoWay, 
                                  UpdateSourceTrigger=PropertyChanged}">

            <TextBlock Name="TitleTextBlock"
                       Text="{Binding Path=MainModel.TitleText,
                                      Mode=TwoWay, 
                                      UpdateSourceTrigger=PropertyChanged}"
                       FontSize="20"
                       HorizontalAlignment="Center"
                       VerticalAlignment="Center"
                       Visibility="Collapsed" />

            <TextBox Name="BannedTextBlock"
                     Text="{Binding Path=MainModel.BannedName,
                                    Mode=TwoWay, 
                                    UpdateSourceTrigger=PropertyChanged}"
                     Visibility="Collapsed" />

            <Button Name="YesButton" 
                    Content="{Binding Path=MainModel.ContentYesButton,
                                      Mode=TwoWay, 
                                      UpdateSourceTrigger=PropertyChanged}" 
                    Visibility="Collapsed" />

            <Button Name="NoButton" 
                    Content="{Binding Path=MainModel.ContentNoButton,
                                      Mode=TwoWay, 
                                      UpdateSourceTrigger=PropertyChanged}" 
                    Visibility="Collapsed" />
        </StackPanel>
    </Grid>

    <DataTemplate.Triggers>
        <DataTrigger Binding="{Binding ElementName=MainViewPanel, Path=Tag}" Value="User">
            <Setter TargetName="TitleTextBlock" Property="Visibility" Value="Visible" />
            <Setter TargetName="YesButton" Property="Visibility" Value="Visible" />
        </DataTrigger>

        <DataTrigger Binding="{Binding ElementName=MainViewPanel, Path=Tag}" Value="Admin">
            <Setter TargetName="TitleTextBlock" Property="Visibility" Value="Visible" />
            <Setter TargetName="BannedTextBlock" Property="Visibility" Value="Visible" />
            <Setter TargetName="YesButton" Property="Visibility" Value="Visible" />
            <Setter TargetName="NoButton" Property="Visibility" Value="Visible" />
        </DataTrigger>
    </DataTemplate.Triggers>
</DataTemplate>

MainViewModel.cs

public class MainViewModel
{
    #region MainModel

    private MainModel _mainModel = null;

    public MainModel MainModel
    {
        get
        {
            return _mainModel;
        }

        set
        {
            _mainModel = value;
        }
    }

    #endregion

    #region UserButton Command

    private ICommand _userButtonCommand = null;

    public ICommand UserButtonCommand
    {
        get
        {
            if (_userButtonCommand == null)
            {
                _userButtonCommand = new RelayCommand(param => this.UserButton(), null);
            }

            return _userButtonCommand;
        }
    }

    private void UserButton() 
    {
        MainModel.ContentType = "User";
        MainModel.TitleText = "Hello User!";
        MainModel.ContentYesButton = "Yes";
        MainModel.ContentNoButton = "No";
    }

    #endregion

    #region AdminButton Command

    private ICommand _adminButtonCommand = null;

    public ICommand AdminButtonCommand
    {
        get
        {
            if (_adminButtonCommand == null)
            {
                _adminButtonCommand = new RelayCommand(param => this.AdminButton(), null);
            }

            return _adminButtonCommand;
        }
    }

    private void AdminButton()
    {
        MainModel.ContentType = "Admin";
        MainModel.TitleText = "Hello Admin!";
        MainModel.BannedName = "John Doe";
        MainModel.ContentYesButton = "Ban";
        MainModel.ContentNoButton = "AntiBan";
    }

    #endregion

    public MainViewModel() 
    {
        MainModel = new MainModel();
    }
}

MainModel.cs

public class MainModel : NotificationObject
{
    #region ContentType

    private string _contentType = "";

    public string ContentType
    {
        get
        {
            return _contentType;
        }

        set
        {
            _contentType = value;
            NotifyPropertyChanged("ContentType");
        }
    }

    #endregion

    #region TitleText

    private string _titleText = "";

    public string TitleText
    {
        get
        {
            return _titleText;
        }

        set
        {
            _titleText = value;
            NotifyPropertyChanged("TitleText");
        }
    }

    #endregion

    #region BannedName

    private string _bannedName = "";

    public string BannedName
    {
        get
        {
            return _bannedName;
        }

        set
        {
            _bannedName = value;
            NotifyPropertyChanged("BannedName");
        }
    }

    #endregion

    #region ContentYesButton

    private string _contentYesButton = "";

    public string ContentYesButton
    {
        get
        {
            return _contentYesButton;
        }

        set
        {
            _contentYesButton = value;
            NotifyPropertyChanged("ContentYesButton");
        }
    }

    #endregion

    #region ContentNoButton

    private string _contentNoButton = "";

    public string ContentNoButton
    {
        get
        {
            return _contentNoButton;
        }

        set
        {
            _contentNoButton = value;
            NotifyPropertyChanged("ContentNoButton");
        }
    }

    #endregion
}

Result for User

Result for user

Result for Admin

Result for admin

Notes about this way

Advantages:

  • just one DataTemplate

Disadvantages:

  • if the representations are very different from each other, in the View the need to manipulate a lot of controls and data.

Conclusion:

This method is suitable for Views, which is not very different from each other, and the number of different values is not too large.

Both examples are available at this link.

like image 156
Anatoliy Nikolaev Avatar answered Sep 28 '22 00:09

Anatoliy Nikolaev