How to get DataGrid columns to stretch from C # code?

Question

I am creating WPF DataGrid columns in my C # code. I want one of the columns to automatically stretch to the width of the DataGrid . In XAML, I set Width="*" . How to do this in code?

EDIT
Some of the answers seem to lead me to the right solution, but I feel like I need to clarify what I'm trying to do:

I really get a new class from a DataGrid . In his constructor, I add four columns:

 this.IsReadOnly = true; this.AutoGenerateColumns = false; this.ItemsSource = m_dataSource; DataGridTextColumn anColumn = new DataGridTextColumn() { Header = "Col1", Binding = new Binding("B1") }; DataGridTextColumn tpColumn = new DataGridTextColumn() { Header = "Col2", Binding = new Binding("B2") }; DataGridTextColumn txColumn = new DataGridTextColumn() { Header = "Col3", Binding = new Binding("B3") }; DataGridTextColumn mdColumn = new DataGridTextColumn() { Header = "Col4", Binding = new Binding("B4") }; this.Columns.Add(anColumn); this.Columns.Add(tpColumn); this.Columns.Add(txColumn); this.Columns.Add(mdColumn); 

I tried to set the last column width as suggested by user24601:

 mdColumn.Width = new DataGridLength(0.5, DataGridLengthUnitType.Star); 

But this creates a column that is so wide that I can scroll and scroll for a very long time ... Same problem when I use 0.1 or even smaller values.

It seems to me that somehow I am doing it wrong?

EDIT 2
Well, I may have a problem because I am actually adding this to ScrollViewer . First I will do some more tests ...

EDIT 3
Well, everything does not work when the DataGrid in a ScrollViewer ... When I delete the ScrollViewer , everything works as user24601.

Answer 1

In fact, you are using something called DataGridLength .

Try something like this:

 Grid.ColumnDefinitions[0].Width = new DataGridLength(0.2, DataGridLengthUnitType.Star); Grid.ColumnDefinitions[1].Width = new DataGridLength(0.8, DataGridLengthUnitType.Star); 

This will split the remaining 80% / 20% space between the two columns.

Answer 2

try it

DataGrid1.Width = double.NaN;