WPF/ XAML /C# Datagrid: how to truncate double to certain number of decimal places?

Question

My DataGrid receives double variables, I want to truncate them to two or three decimal places. My xaml code:

        <DataGrid Name="McDataGrid" ItemsSource="{Binding}" Visibility="Collapsed" HorizontalAlignment="Center" 
                  Margin="0, 200, 0, 0" VerticalAlignment="Top" CanUserAddRows="False" />

All of my C# code that touches the datagrid:

        McDataGrid.DataContext = fillingDataGridUsingDataTable(string input).DefaultView;
        McDataGrid.Visibility = Visibility.Visible;

fillingDataGridUsingDataTable(input) is a function that returns a DataTable with headers in string and values in double.

Answer 1

You can use the ToString together with the format specifier F with a precision specifier (Standard format specifiers). The DataGrid will convert the double value to a string anyway, so ToString will do it. Use the overload that accepts a IFormatProvider to make the result use the correct decimal separator for the current system's language.

The following example creates numeric string from a double value with a precision of 3 decimal places:

double value = 1.23456;
var numericString = value.ToString("F3", CultureInfo.CurrentCulture); // "1.235"

To convert the double value use the Math.Round helper:

double value = 1.23456;
double roundValue = Math.Round(value, 3); // 1.235