WPF Binding to a DataGrid from a DataTable of Objects

Question

I'm still new to Databinding and have been reading and researching this question for hours now, and I'm hoping someone can at least point me in the right direction.

What I have is a DataTable populated with the objects such as:

public class SimpleObject
{

    public string DisplayValue { get; set; }
    public bool Match { get; set; }
    public string BackGroundColor
    {
        get { if (Match) return "Green"; else return "White"; }
        set { //do nothing }
    }

}

I've set up my headers for the columns of the datatable as such:

DataTable MyDataTable = new DataTable()
List headers = new List<string>() {"Header1", "Header2", "Header3", "Header4"}
foreach (string key in headers)
{         
    MyDataTable.Columns.Add(new DataColumn(key, typeof(SimpleObject)));
}

And populated my DataTable rows by adding rows similar to:

SimpleObject[] rowList = new SimpleObject[4]
DataRow dataRow = MyDataTable.NewRow();
for(int i = 0; i < 4; i++)
{
    //Not really how I determine values, but this will do for a basic example
    rowList[i].DisplayValue = i.ToString();
    rowList[i].Match = i % 2 == 0;
}
dataRow.ItemArray = rowList;
MyDataTable.Rows.Add(dataRow);

SimpleDataGrid.DataContext = MyDataTable;

Now, what I want to do is bind MyDataTable to the DataGrid such that:

SimpleObject.DisplayValue is shown in the cell's value
the background color of the cell is determined by SimpleObject.BackGroundColor

If anyone could give me advice as to how to this, I would much appreciate it! So far I've tried doing something similar to this:

 <DataGrid Name="SimpleDataGrid" 
                      AutoGenerateColumns="False"
                      ItemsSource="{Binding}">
                <DataGrid.Columns>
                    <DataGridTemplateColumn Header="Header1" Width="100">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Path=Header1.DisplayValue}"
                                           BackGround="{Binding Path=Header1.BackGroundColor}"
                                   />
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                </DataGrid.Columns>

 </DataGrid>

But had no luck. I can't even get the DisplayValue to bind to the Text (even without trying to bind BackGroundColor). Any help or direction would be greatly appreciated!

The set for BackgroundColor is an infinite loop, but likely not your problem at hand. — user7116
True, I made that object quickly to simplify my real object. Fixed though — mario87
I can't test it atm, but I wonder if it would work if your BackgroundColor property was of type Brush and it returned Brushes.Green or Brushes.White — vlad
Well, as is, I am not even getting the text to bind. I guess I should clarify that in the question — mario87
I see. I'm pretty sure you don't need Header1 in the Path property; it should be something like Path=DisplayValue — vlad

Peter Hansen Peter Hansen · Accepted Answer · 2012-11-28T20:11:16

I have tried replicating your problem, but it seems to work fine for me.

I have added 2 columns to the DataGrid, and the DataTable has 1 item added to it, so 1 row will be created.

The TextBlocks have both the Text and Background properties bound correctly.

Here is the the source code I have used. See if it works for you.

XAML:

<DataGrid Name="SimpleDataGrid" 
                  AutoGenerateColumns="False"
                  ItemsSource="{Binding}">
    <DataGrid.Columns>
        <DataGridTemplateColumn Header="Header1" Width="100">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Path=Header1.DisplayValue}"
                               Background="{Binding Path=Header1.BackGroundColor}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
        <DataGridTemplateColumn Header="Header2" Width="100">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Path=Header2.DisplayValue}"
                               Background="{Binding Path=Header2.BackGroundColor}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Code-behind:

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();

        DataTable MyDataTable = new DataTable();
        List<string> headers = new List<string>() { "Header1", "Header2", "Header3", "Header4" };

        foreach (string key in headers)
        {         
            MyDataTable.Columns.Add(new DataColumn(key, typeof(SimpleObject)));
        }

        SimpleObject[] rowList = new SimpleObject[4];
        DataRow dataRow = MyDataTable.NewRow();

        for (int i = 0; i < 4; i++)
        {
            //Not really how I determine values, but this will do for a basic example
            rowList[i] = new SimpleObject();
            rowList[i].DisplayValue = i.ToString();
            rowList[i].Match = i % 2 == 0;
        }
        dataRow.ItemArray = rowList;
        MyDataTable.Rows.Add(dataRow);

        SimpleDataGrid.DataContext = MyDataTable;
    }        
}

public class SimpleObject
{
    public string DisplayValue { get; set; }
    public bool Match { get; set; }
    public string BackGroundColor
    {
        get 
        { 
            if (Match) 
                return "Green"; 
            else return "Blue"; 
        }
    }
}

WPF Binding to a DataGrid from a DataTable of Objects

1 Answers