Move Focus to next Control in WPF

Question

Suppose I have a DataGrid and a Button. CanUserAddRows is set to True. Let this dataGrid have two DataGridTextColumns namely "Name" and "Age".

Now if user takes the following actions :

1. He adds name as XYZ and Age as 20. Then he press enter. So a new row will be added to the datagrid.
2. He adds name as ABC and Age as 12. Then he press enter. So a new row will be added to the datagrid.
3. He keeps name empty and press Enter or TAB then I want to move focus to Button instead of next cell of datagrid.

I have watched many questions but I don't get the logic of if user left the name empty and how do I move focus to Button instead of next cell.

Answer 1

Use DataGridView.SelectedCells[0] so you can retrieve the value of the selected cell (assuming you can only select one).

To get the actual string inside, you will have to cast the content to a proper WPF object, like TextBlock. myCell.Column.GetCellContent(cell.Item) as TextBlock

Then in a PreviewKeyDown event handler (KeyDown having known issues in DataGridView), you can use button.Focus(). (more about those issues)

//...
myDataGrid1.PreviewKeyDown += myDataGrid1_KeyDown;
//...
void myDataGrid1_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
    if (e.Key == System.Windows.Input.Key.Enter)
    {
        var cell = myDataGrid1.SelectedCells[0];
        TextBlock cellContent = cell.Column.GetCellContent(cell.Item) as TextBlock;
        if (cellContent != null)
        {
            if (String.IsNullOrWhitespace(cellContent.Text))
                button.Focus();
        }
    }
}

About getting the column's name, it's another question, for which you can find answer here for example.

As a side note, you're not really supposed to interact directly with a DataGridView cells' values, since it's meant to be bound with a data source from which you should retrieve the data you want to test. However, you can search a bit for helper methods that can help you get what you want.

Answer 2

You can define a handler for the DataGrid.KeyDown event, as:

void myDataGrid1_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
    if (e.Key == System.Windows.Input.Key.Enter)
    {
        button.Focus();
    }
}