c# - How to bind an 2D array bool[][] to a WPF DataGrid (one-way)?

Question

I have a matrix kind datagrid like this.

this grid is designed entirely in XAML

Now how to insert values into these datagridcell with 2 dimensional array ? the values which is needed to be inserted must be of bool datatype (either TRUE or FALSE). Any ideas ?

Answer 1

Here is my approach for a MVVM scenario, using a converter which creates a DataView which can be bound to the grids ItemsSource. It's for a special Matrix datatype which holds doubles, but you'll be able to modify it yourself for your requirements:

public class MatrixToDataViewConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var array = value as Matrix;
        if (array == null) return null;

        //var array = ILMath.rand(3, 5);

        var rows = array.Dimensions[0];
        var columns = array.Dimensions[1];

        var t = new DataTable();
        for (var c = 0; c < columns; c++)
        {
            t.Columns.Add(new DataColumn(c.ToString()));
        }

        for (var r = 0; r < rows; r++)
        {
            var newRow = t.NewRow();
            for (var c = 0; c < columns; c++)
            {
                var v = array[r, c];

                // Round if parameter is set
                if (parameter != null)
                {
                    int digits;
                    if (int.TryParse(parameter.ToString(), out digits))
                        v = Math.Round(v, digits);
                }

                newRow[c] = v;
            }

            t.Rows.Add(newRow);
        }


        return t.DefaultView;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Define a resource for the converter:

<converter:MatrixToDataViewConverter x:Key="MatrixToDataViewConverter" />

And use it like this:

<DataGrid ItemsSource="{Binding Matrix, Converter={StaticResource MatrixToDataViewConverter}, ConverterParameter=1}"/>

It doesn't allow two way binding, though...

EDIT

Here's the version for an array bool[][]:

public class BoolArrayToDataViewConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var array = value as bool[,];
        if (array == null) return null;

        var rows = array.GetLength(0);
        if (rows == 0) return null;

        var columns = array.GetLength(1);
        if (columns == 0) return null;

        var t = new DataTable();

        // Add columns with name "0", "1", "2", ...
        for (var c = 0; c < columns; c++)
        {
            t.Columns.Add(new DataColumn(c.ToString()));
        }

        // Add data to DataTable
        for (var r = 0; r < rows; r++)
        {
            var newRow = t.NewRow();
            for (var c = 0; c < columns; c++)
            {
                newRow[c] = array[r, c];
            }
            t.Rows.Add(newRow);
        }

        return t.DefaultView;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

and the usage:

<DataGrid ItemsSource="{Binding Matrix, Converter={StaticResource BoolArrayToDataViewConverter}}"/>

And this is what it looks like in the very raw version. You can then style the DataGrid and edit it's templates, but this is another question...