How to populate a WPF grid based on a 2-dimensional array
.NetWpfData BindingTemplatesGrid.Net Problem Overview
I have a 2-dimensional array of objects and I basically want to databind each one to a cell in a WPF grid. Currently I have this working but I am doing most of it procedurally. I create the correct number of row and column definitions, then I loop through the cells and create the controls and set up the correct bindings for each one.
At a minimum I would like to be able to use a template to specify the controls and bindings in xaml. Ideally I would like to get rid of the procedural code and just do it all with databinding, but I'm not sure that's possible.
Here is the code I am currently using:
public void BindGrid()
{
m_Grid.Children.Clear();
m_Grid.ColumnDefinitions.Clear();
m_Grid.RowDefinitions.Clear();
for (int x = 0; x < MefGrid.Width; x++)
{
m_Grid.ColumnDefinitions.Add(new ColumnDefinition() { Width = new GridLength(1, GridUnitType.Star), });
}
for (int y = 0; y < MefGrid.Height; y++)
{
m_Grid.RowDefinitions.Add(new RowDefinition() { Height = new GridLength(1, GridUnitType.Star), });
}
for (int x = 0; x < MefGrid.Width; x++)
{
for (int y = 0; y < MefGrid.Height; y++)
{
Cell cell = (Cell)MefGrid[x, y];
SolidColorBrush brush = new SolidColorBrush();
var binding = new Binding("On");
binding.Converter = new BoolColorConverter();
binding.Mode = BindingMode.OneWay;
BindingOperations.SetBinding(brush, SolidColorBrush.ColorProperty, binding);
var rect = new Rectangle();
rect.DataContext = cell;
rect.Fill = brush;
rect.SetValue(Grid.RowProperty, y);
rect.SetValue(Grid.ColumnProperty, x);
m_Grid.Children.Add(rect);
}
}
}
.Net Solutions
Solution 1 - .Net
The purpose of the Grid is not for real databinding, it is just a panel. I am listing down the easiest way to accomplish the visualization of a two dimensional list
<Window.Resources>
<DataTemplate x:Key="DataTemplate_Level2">
<Button Content="{Binding}" Height="40" Width="50" Margin="4,4,4,4"/>
</DataTemplate>
<DataTemplate x:Key="DataTemplate_Level1">
<ItemsControl ItemsSource="{Binding}" ItemTemplate="{DynamicResource DataTemplate_Level2}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</DataTemplate>
</Window.Resources>
<Grid>
<ItemsControl x:Name="lst" ItemTemplate="{DynamicResource DataTemplate_Level1}"/>
</Grid>
And in the code behind set the ItemsSource of lst with a TwoDimentional data structure.
public Window1()
{
List<List<int>> lsts = new List<List<int>>();
for (int i = 0; i < 5; i++)
{
lsts.Add(new List<int>());
for (int j = 0; j < 5; j++)
{
lsts[i].Add(i * 10 + j);
}
}
InitializeComponent();
lst.ItemsSource = lsts;
}
This gives you the following screen as output. You can edit the DataTemplate_Level2 to add more specific data of your object.
Solution 2 - .Net
Here is a Control called DataGrid2D
that can be populated based on a 2D or
1D array (or anything that implements the IList
interface). It subclasses DataGrid
and adds a property called ItemsSource2D
which is used for binding against 2D or 1D sources. Library can be downloaded here and source code can be downloaded here.
To use it just add a reference to DataGrid2DLibrary.dll, add this namespace
xmlns:dg2d="clr-namespace:DataGrid2DLibrary;assembly=DataGrid2DLibrary"
and then create a DataGrid2D and bind it to your IList, 2D array or 1D array like this
<dg2d:DataGrid2D Name="dataGrid2D"
ItemsSource2D="{Binding Int2DList}"/>
OLD POST
Here is an implementation that can bind a 2D array to the WPF datagrid.
Say we have this 2D array
private int[,] m_intArray = new int[5, 5];
...
for (int i = 0; i < 5; i++)
{
for (int j = 0; j < 5; j++)
{
m_intArray[i,j] = (i * 10 + j);
}
}
And then we want to bind this 2D array to the WPF DataGrid and the changes we make shall be reflected in the array. To do this I used Eric Lippert's Ref
public class Ref<T>
{
private readonly Func<T> getter;
private readonly Action<T> setter;
public Ref(Func<T> getter, Action<T> setter)
{
this.getter = getter;
this.setter = setter;
}
public T Value { get { return getter(); } set { setter(value); } }
}
Then I made a static helper class with a method that could take a 2D array and return a DataView using the Ref class above.
public static DataView GetBindable2DArray<T>(T[,] array)
{
DataTable dataTable = new DataTable();
for (int i = 0; i < array.GetLength(1); i++)
{
dataTable.Columns.Add(i.ToString(), typeof(Ref<T>));
}
for (int i = 0; i < array.GetLength(0); i++)
{
DataRow dataRow = dataTable.NewRow();
dataTable.Rows.Add(dataRow);
}
DataView dataView = new DataView(dataTable);
for (int i = 0; i < array.GetLength(0); i++)
{
for (int j = 0; j < array.GetLength(1); j++)
{
int a = i;
int b = j;
Ref<T> refT = new Ref<T>(() => array[a, b], z => { array[a, b] = z; });
dataView[i][j] = refT;
}
}
return dataView;
}
This would almost be enough to bind to but the Path in the Binding will point to the Ref
<DataGrid Name="c_dataGrid"
RowHeaderWidth="0"
ColumnHeaderHeight="0"
AutoGenerateColumns="True"
AutoGeneratingColumn="c_dataGrid_AutoGeneratingColumn"/>
private void c_dataGrid_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
{
DataGridTextColumn column = e.Column as DataGridTextColumn;
Binding binding = column.Binding as Binding;
binding.Path = new PropertyPath(binding.Path.Path + ".Value");
}
And after this we can use
c_dataGrid.ItemsSource = BindingHelper.GetBindable2DArray<int>(m_intArray);
And the output will look like this
Any changes made in the DataGrid
will be reflected in the m_intArray.
Solution 3 - .Net
I wrote a small library of attached properties for the DataGrid
.
Here is the source
Sample, where Data2D is int[,]
:
<DataGrid HeadersVisibility="None"
dataGrid2D:Source2D.ItemsSource2D="{Binding Data2D}" />
Renders:
Solution 4 - .Net
Here is another solution based on Meleak's answer but without requiring for an AutoGeneratingColumn
event handler in the code behind of each binded DataGrid
:
public static DataView GetBindable2DArray<T>(T[,] array)
{
var table = new DataTable();
for (var i = 0; i < array.GetLength(1); i++)
{
table.Columns.Add(i+1, typeof(bool))
.ExtendedProperties.Add("idx", i); // Save original column index
}
for (var i = 0; i < array.GetLength(0); i++)
{
table.Rows.Add(table.NewRow());
}
var view = new DataView(table);
for (var ri = 0; ri < array.GetLength(0); ri++)
{
for (var ci = 0; ci < array.GetLength(1); ci++)
{
view[ri][ci] = array[ri, ci];
}
}
// Avoids writing an 'AutogeneratingColumn' handler
table.ColumnChanged += (s, e) =>
{
var ci = (int)e.Column.ExtendedProperties["idx"]; // Retrieve original column index
var ri = e.Row.Table.Rows.IndexOf(e.Row); // Retrieve row index
array[ri, ci] = (T)view[ri][ci];
};
return view;
}
Solution 5 - .Net
You may want to check out this link: http://www.thinkbottomup.com.au/site/blog/Game_of_Life_in_XAML_WPF_using_embedded_Python
If you use a List within a List you can use myList[x][y] to access a cell.