Question

I have a DataGrid which gets its data from an sql table. I have set AutoGenerateColumns to true.

When I click a button the data in the DataGrid is exported to a pdf-file.

However when the width of all columns combined in the DataGrid is bigger than about 800 the table is bigger than the page inside the pdf.

I have set the DataGrid’s MaxWidth-Property to 800. When I resize a column I can drag the cursor outside of the DataGrid and a horizontal scrollbar appears.

Is there a way to limit the maximum size of all columns combined to 800 so that I can not make the column bigger than the DataGrid?

Answer 1

The easy solution is to make the DataGrid use starsizing for its columns by simply setting the ColumnWidth property like this:

<DataGrid Width="800" ColumnWidth="*" />

The problem however, is that this makes all columns equally wide, which is probably not desired.

So what I would do, is to first create all columns the default way like you do now, and then set each column to a starsize afterwards. That way a value can be calculated for the new width, that makes the column keep its initial size.

I have written a small piece of code, to show what i mean..

XAML

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication2"
        Title="MainWindow" Height="350" Width="850">
    <StackPanel>
        <DataGrid x:Name="dgTest" Width="800" Loaded="dgTest_Loaded" />
    </StackPanel>
</Window>

Code-behind

public partial class MainWindow : Window
{
    public class Test
    {
        public string P1 { get; set; }
        public string P2 { get; set; }
        public string P3 { get; set; }
    }

    public MainWindow()
    {
        InitializeComponent();

        var t = new List<Test>(new[] { 
            new Test{ P1="på,dsl", P2="234234", P3="asdasdasd"},
            new Test{ P1="asasaspå,dsl", P2="23sadasd asf afasdasdasd4234", P3="asdasdasd" }, 
            new Test{ P1="på,ds1231l", P2="234", P3="1ddsdasd" },
        });

        dgTest.ItemsSource = t;
    }

    private void dgTest_Loaded(object sender, RoutedEventArgs e)
    {
        //Make the columns use starsizing so their combined width
        //can't be bigger than the actual datagrid that contains them.
        foreach (var column in dgTest.Columns)
        {
            var starSize = column.ActualWidth / dgTest.ActualWidth;
            column.Width = new DataGridLength(starSize, DataGridLengthUnitType.Star);
        }
    }
}