How to apply String formatting in DataGrid – WPF

I have a Data Grid in WPF that has columns of CPF, RG, ZIP, and others, I need to do the formatting for:

CPF: 111.111.111-11

RG: 11.111.111-1 With number at end

RG: 11.111.111-A With letter at the end

CEP: 11111-11

Just fill in the data and do not format.

<Window x_Class="ProjSistema.Wpf.Cadastro.Teste"
    
    xmlns_x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Teste" Height="300" Width="300">
<Grid>
    <DataGrid  Name="dtgTeste" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Header="CPF" MinWidth="100" Binding="  {Binding CPF, StringFormat={}{0:###.###.###-##}}"/>
            <DataGridTextColumn Header="RG" MinWidth="100" Binding="{Binding RG, StringFormat={}{0:##.###.###-#}}" />
            <DataGridTextColumn Header="CEP" MinWidth="100" Binding="{Binding CEP, StringFormat={}{0:#####-##}}" />
        </DataGrid.Columns>
    </DataGrid>
</Grid>

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

        List<PropriedadeTeste> lstTeste = new List<PropriedadeTeste>();
        PropriedadeTeste propTeste = new PropriedadeTeste();
        propTeste.CPF = "11111111111";
        propTeste.RG = "111111111";
        propTeste.CEP = "11111111";
        lstTeste.Add(propTeste);
        dtgTeste.ItemsSource = lstTeste;
    }
}

You can apply the StringFormat to Binding this way:

<DataGrid  Name="dtgTeste" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTextColumn Header="CPF" Binding="{Binding CPF, StringFormat={}{0:###.###.###-##}}"/>
        <DataGridTextColumn Header="RG" Binding="{Binding RG, StringFormat={}{0:##.###.###-#}}" />
        <DataGridTextColumn Header="CEP" Binding="{Binding CEP, StringFormat={}{0:#####-##}}" />
    </DataGrid.Columns>
</DataGrid>

There are also other methods creating a custom class to do the formatting.

Basically you will create a class or struct that contains the data you want to bind to the datagrid and this class will be responsible for receiving and formatting the data (since this data type can not be formatted)

(in the example below format a field TimeSpan in Text with values in mm:ss and its corresponding in centesimal basis (total minutes)

public class InformacaoGridMeio: ViewModelBase
{
    public long Id { get; set; }
    public int Execucao { get; set; }
    public TimeSpan TempoExecucaoTime { get; set; }
    public string TempoExecucao  => TempoExecucaoTime != TimeSpan.Zero
            ? $"{TempoExecucaoTime.Minutes:00}:{TempoExecucaoTime.Seconds:00} ({TempoExecucaoTime.TotalMinutes:00.00})"
            : "--:-- (--,--)";
}

After creating this class, create your property in the ViewModel and this property is bound to the DataGrid

public ObservableCollection<InformacaoGridMeio> DataGridMeio
    {
        get { return _gridMeio; }
        set { _gridMeio = value; OnPropertyChanged("DataGridMeio"); }
    }


<DataGrid ColumnWidth="*" 
          AutoGenerateColumns="False" 
          SelectionMode="Single"  
          HorizontalContentAlignment="Center" 
          ItemsSource="{Binding DataGridMeio}" 
          VerticalScrollBarVisibility="Auto"
          HorizontalScrollBarVisibility="Auto"
          ScrollViewer.CanContentScroll="True"
>

Make a friend convert.

<DataGridTextColumn Header="CPF" MinWidth="100" Binding="  {Binding CPF, Converter={StaticResource NationalRegistrationConverter}}"/>

Follow the converter I use.

/// <summary>
/// Valida um texto para ver se é um CNPJ ou CPF
/// </summary>
[ValueConversion(typeof(object), typeof(String))]
public class NationalRegistrationValueConverter : IValueConverter
{
    /// <summary>
    /// Converte o valor para o bindind de um objeto source
    /// </summary>
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // Se não estiver vazio         
        if (value != null)
        {
            // Variaveis
            string OldValue = ((string)value).ToString().Trim();
            string NewValue = "";

            // Se tiver 10 caracteres
            if (OldValue.Length == 11)
            {
                // Recebe o valor formatado
                NewValue = OldValue.Insert(3, ".").Insert(7, ".").Insert(11, "-"); ;
            }
            // Se tiver 11 caracteres
            else if (OldValue.Length == 14)
            {
                // Recebe o valor formatado
                NewValue = OldValue.Insert(2, ".").Insert(6, ".").Insert(10, "/").Insert(15, "-");
            }

            // Retorna o novo valor
            return NewValue;
        }

        // Retorna o valor que veio
        return value;
    }

    /// <summary>
    /// Converte o valor do binding devolta para o objeto source
    /// </summary>
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // Se nao estiver vazio
        if (value != null)
        {
            // Recebe o valor sem os caracteres especiais
            string OldValue = value.ToString().Replace("-", string.Empty).Replace("/", "").Replace(".", "");

            // Retorna o valor em decimal
            return OldValue;
        }

        // Retorna o valor
        return value;
    }
}

Do not forget to declare in the feature of your window or control the convert.

 <Window.Resources>
    <control:NationalRegistrationValueConverter x_Key="NationalRegistrationConverter"/>    
</Window.Resources>