WPF

private List<bool> _OnOffValues;
public List<bool> OnOffValues
{
    get { return _OnOffValues; }
    set
    {
        if (_OnOffValues != value)
        {
            _OnOffValues = value;
            RaisePropertyChanged("OnOffValues");
        }
    }
}
public MyControl()
{
    InitializeComponent();
    this.DataContext = this;
    OnOffValues = new List<bool>();
    for (int x = 0; x < 24; x++)
    {
        OnOffValues.Add(true);
    }
}

<CheckBox Grid.Row="0"
            Grid.Column="0"
            IsChecked="{Binding OnOffValues[0], ElementName=control}"/>

System.Windows.Data Error: 17 : Cannot get 'Item[]' value (type 'Boolean') from 'OnOffValues' (type 'List`1'). BindingExpression:Path=OnOffValues[0]; DataItem='MyControl' (Name='control'); target element is 'CheckBox' (Name=''); target property is 'IsChecked' (type 'Nullable`1') ArgumentOutOfRangeException:'System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index'

var dragObj = new DataObject();
dragObj.SetFileDropList(new StringCollection() { @"H:\Temp\popeye.svg" });
DragDrop.DoDragDrop(new Window(), dragObj, DragDropEffects.Copy);

<datepicker>

        <datepicker.selecteddate>
            <binding path="DateDeb" stringformat="d" validatesondataerrors="True">
                  <binding.validationrules>
                        <communpresentation:regledatevalide>




        <datepicker.resources>

               <Setter Property="Control.Template">
                   <Setter.Value>
                        <ControlTemplate>
                          <CommunPresentation:MaskedTextbox Mask="##/##/####" Text="{Binding Path=DateDeb}" />
                        </controltemplate>
                    </setter.Value>
                </setter>

<Style x:Key="backButton" TargetType="{x:Type Button}">

    <Setter Property="SnapsToDevicePixels" Value="True"/>
    <Setter Property="OverridesDefaultStyle" Value="True"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">

                <Grid>

                    <Ellipse Grid.Column="0"
                             Grid.Row="0"
                             Canvas.Top="2"
                             Canvas.Left="2"
                             Fill="Transparent"
                             Height="35"
                             Width="35"
                             StrokeThickness="2"
                             Stroke="#6E6E6E"
                             Margin="2"
                             x:Name="part_ellipse"/>

                    <Path Grid.Column="0"
                          Grid.Row="0"
                          Margin="12,10,0,0"
                          Fill="#6E6E6E"
                          Data="M 0 10 L 10 0 L 10 20 Z"
                          x:Name="part_path"/>

                </Grid>

                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="part_ellipse" Property="Fill" Value="#CCCCCC" />
                        <Setter TargetName="part_path" Property="Fill" Value="#CCCCCC" />
                    </Trigger>
                </ControlTemplate.Triggers>

            </ControlTemplate>
        </Setter.Value>
    </Setter>

</Style>

private async void button_Click(object sender, RoutedEventArgs e)
       {
           await this.ShowMessageAsync("Attention", "The product is out of range");

       }

<DataGrid Grid.Row="1"
            x:Name="dataGrid"
            AutoGenerateColumns="False"
            BorderBrush="SteelBlue"
            BorderThickness="1"
            Margin="5"/>

private ObservableCollection<DataGridColumn> _ColumnCollection;
public ObservableCollection<DataGridColumn> ColumnCollection
{
    get { return _ColumnCollection; }
    set
    {
        if (_ColumnCollection != value)
        {
            _ColumnCollection = value;
            RaisePropertyChanged("ColumnCollection");
        }
    }
}

private DataTable _Datatable;
public DataTable Datatable
{
    get { return _Datatable; }
    set
    {
        if (_Datatable != value)
        {
            _Datatable = value;
            RaisePropertyChanged("Datatable");
        }
    }
}

private void CreateGrid()
{
    Datatable = new DataTable();
    ColumnCollection = new ObservableCollection<DataGridColumn>();

    Datatable.Columns.Add("Fruit", typeof(string));

    Datatable.Rows.Add("Apples");
    Datatable.Rows.Add("Oranges");
    Datatable.Rows.Add("Grapes");

    dataGrid.Columns.Add(new DataGridTextColumn()
    {
        Header = "Fruit Name",
        Width = new DataGridLength(200),
        FontSize = 12,
        Binding = new Binding("Fruit")
    });

    var row = Datatable.Rows[0];

    dataGrid.ItemsSource = Datatable.Rows;
}

System.Windows.Data Error: 40 : BindingExpression path error: 'Fruit' property not found on 'object' ''DataRow' (HashCode=51379511)'. BindingExpression:Path=Fruit; DataItem='DataRow' (HashCode=51379511); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')

<DataGrid Grid.Row="1"
            x:Name="dataGrid"
            AutoGenerateColumns="False"
            BorderBrush="SteelBlue"
            BorderThickness="1"
            Margin="5"/>

private ObservableCollection<DataGridColumn> _ColumnCollection;
public ObservableCollection<DataGridColumn> ColumnCollection
{
    get { return _ColumnCollection; }
    set
    {
        if (_ColumnCollection != value)
        {
            _ColumnCollection = value;
            RaisePropertyChanged("ColumnCollection");
        }
    }
}

private DataTable _Datatable;
public DataTable Datatable
{
    get { return _Datatable; }
    set
    {
        if (_Datatable != value)
        {
            _Datatable = value;
            RaisePropertyChanged("Datatable");
        }
    }
}

private void CreateGrid()
{
    Datatable = new DataTable();
    ColumnCollection = new ObservableCollection<DataGridColumn>();

    Datatable.Columns.Add("Fruit", typeof(string));

    Datatable.Rows.Add("Apples");
    Datatable.Rows.Add("Oranges");
    Datatable.Rows.Add("Grapes");

    dataGrid.Columns.Add(new DataGridTextColumn()
    {
        Header = "Fruit Name",
        Width = new DataGridLength(200),
        FontSize = 12,
        Binding = new Binding("Fruit")
    });

    var row = Datatable.Rows[0];

    dataGrid.ItemsSource = Datatable.Rows;
}

System.Windows.Data Error: 40 : BindingExpression path error: 'Fruit' property not found on 'object' ''DataRow' (HashCode=51379511)'. BindingExpression:Path=Fruit; DataItem='DataRow' (HashCode=51379511); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')

<ListBox ItemsSource="{Binding ProjectDurations}">

    <ListBox.ItemTemplate>
        <DataTemplate>

            <ctrls:ProjectDurationsView BuildingTypeCaption="{Binding BuildingType}"
                                        SchedulePacks="{Binding Columns}"/>

        </DataTemplate>
    </ListBox.ItemTemplate>

</ListBox>

"'BuildingType' property not found on 'object' ''ProjectDurationsView'"
"'Columns' property not found on 'object' ''ProjectDurationsView'"