Create a custom DataGrid's ItemsSource

c#, data-binding, datagrid, wpf

Solution

Okay, let me try to take an example which is similar to your needs

Let's assume we use this class:

public class MyObject
{
   public int MyID;
   public string MyString;
   public ICommand MyCommand;
}

And we are willing to display a `DataGrid` listing the ID, and having as a second column a `Button`, with the property `MyString` as content, which, when clicked, launches the `ICommand` `MyCommand` which opens in a new window whatever you want.

Here is what you should have on the View side:

    <DataGrid ItemsSource="{Binding MyList}" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Header="ID" Binding="{Binding MyID}" />
            <DataGridTemplateColumn Header="Buttons">
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <Button Content="{Binding MyString}" Command="{Binding MyCommand}" />
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
    </DataGrid>

This will show a `DataGrid` taking all the content in an `IEnumerable<MyObject>` named 'MyList', and shows two columns as defined before.

Now if you need to define the command. First, I recommend you read this introductory link to MVVM and take the `RelayCommand` class (that's what we're gonna use for your problem)

So, in your `ViewModel`, the one which defines the `MyList`, here is how you should define some of the useful objects:

public ObservableCollection<MyObject> MyList { get; set; }

// blah blah blah

public void InitializeMyList()
{
  MyList = new ObservableCollection<MyObject>();
  for (int i = 0; i < 5; i++)
  {
    MyList.Add(InitializeMyObject(i));
  }
}

public MyObject InitializeMyObject(int i)
{
  MyObject theObject = new MyObject();
  theObject.MyID = i;
  theObject.MyString = "The object " + i;
  theObject.MyCommand = new RelayCommand(param =< this.ShowWindow(i));
  return theObject
}

private void ShowWindow(int i)
{
  // Just as an exammple, here I just show a MessageBox
  MessageBox.Show("You clicked on object " + i + "!!!");
}

Problem

I am working with DataGrids but I am struggling to binding my data since the number of columns varies depending of the info that has to be showed. So, what I have tried to do is to create and object which contains all the columns and rows that I need at some point and binding this object to the `ItemsSource` property. Since I have worked with DataGridViews in WindowsForms I have in mind something like this: ``` DataTable myTable = new DataTable(); DataColumn col01 = new DataColumn("col 01"); myTable.Columns.Add(col01); DataColumn col02 = new DataColumn("col 02"); myTable.Columns.Add(col02); DataRow row = myTable.NewRow(); row[0] = "data01"; row[1] = "data02"; myTable.Rows.Add(row); row = myTable.NewRow(); row[0] = "data01"; row[1] = "data02"; myTable.Rows.Add(row); ``` But I haven't been able to find a way to do the same thing in WPF since I need some columns to be DataGridComboBoxColumns for example. Actually I have read many post about it in this site, but none of them helped to me. I am really lost. Could anyone help me? I just need to be able to create a table which may contain DataGridTextColumns or `DataGridComboBoxColumns, etc, In order to bind this final object to the DataGrid's ItemsSource property. Hope someone can help me.

Original source