How to validate RichTextbox in WPF? - wpf

Question

How to validate RichTextbox in WPF? I want to validate the text for email and email separator i.e. emails should be entered with a semicolon.
Xaml:
<StackPanel Orientation="Horizontal">
<RichTextBox x:Name="txtEmail" Style="{StaticResource ContentRichTextBox}"
ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Auto" Margin="0,0,10,0">
<FlowDocument>
<Paragraph LineHeight="5"></Paragraph>
</FlowDocument >
</RichTextBox>
</StackPanel>
<StackPanel HorizontalAlignment="Center">
<TextBlock x:Name="txterrormessage" Width="300" Foreground="#FFE5572C" FontSize="14" Visibility="Hidden" TextWrapping="Wrap"></TextBlock>
</StackPanel>
<StackPanel HorizontalAlignment="Center" Margin="60,0,0,0">
<Button x:Name="BtnEmail" Style="{StaticResource ShortButtonStyle}" Content="NEXT" Margin="10" Command="{Binding CommandChanged}" CommandParameter="PROJECTS" Click="BtnEmail_Click"/>
</StackPanel>
This is my code:
private void BtnEmail_Click(object sender, RoutedEventArgs e)
{
string richText = new TextRange(txtEmail.Document.ContentStart, txtEmail.Document.ContentEnd).Text;
if (!Regex.IsMatch(richText, #"^[a-zA-Z][\w\.-]*[a-zA-Z0-9]#[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"))
{
txterrormessage.Text = "Enter a valid email";
txterrormessage.Visibility = System.Windows.Visibility.Visible;
}
else
{
txterrormessage.Visibility = System.Windows.Visibility.Hidden;
}
if (!Regex.IsMatch(richText, #"^((\w+([-+.]\w+)*#\w+([-.]\w+)*\.\w+([-.]\w+)*)\s*[;]{0,1}\s*)+$"))
{
txterrormessage.Text = "Separate emails with ;";
txterrormessage.Visibility = System.Windows.Visibility.Visible;
}
}
The code doesnt seem to work....How to validate?
Thanks

Answer 1

The simplest way I've seen to do this is
private void OnVerifyEmail()
{
var recipients = richText.Split(';', StringSplitOptions.RemoveEmptyEntries);
var validator = new System.ComponentModel.DataAnnotations.EmailAddressAttribute();
foreach (var recipient in recipients)
{
var isValid = validator.IsValid(recipient.Trim());
if(!isValid)
{
// do your thing here
}
}
}

Answer 2

format your richText before validation:
richText = Regex.Replace(richText, #"(\n|\r)", "", RegexOptions.Multiline);
Edit:
This is the whole method and probably what you're looking for:
private void BtnEmail_Click(object sender, RoutedEventArgs e)
{
string richText = new TextRange(txtEmail.Document.ContentStart, txtEmail.Document.ContentEnd).Text;
richText = Regex.Replace(richText, #"(\n|\r)", "", RegexOptions.Multiline);
richText = Regex.Replace(richText, #"( ;|; )", ";", RegexOptions.Multiline);
txterrormessage.Visibility = System.Windows.Visibility.Hidden;
if (!Regex.IsMatch(richText, #"^[\W]*([\w+\-.%]+#[\w\-.]+\.[A-Za-z]{2,4}[\W]*,{1}[\W]*)*([\w+\-.%]+#[\w\-.]+\.[A-Za-z]{2,4})[\W]*$"))
{
string[] emails = Regex.Split(richText, ";", RegexOptions.Multiline);
foreach (string item in emails)
{
if (string.IsNullOrEmpty(item))
continue;
if (!Regex.IsMatch(item, #"^\w+([-+.']\w+)*#\w+([-.]\w+)*\.\w+([-.]\w+)*$"))
{
txterrormessage.Text = item + " is not a valid email address";
txterrormessage.Visibility = System.Windows.Visibility.Visible;
break;
}
}
if (string.IsNullOrEmpty(txterrormessage.Text))
{
txterrormessage.Text = "Separate emails with ; ";
txterrormessage.Visibility = System.Windows.Visibility.Visible;
}
}
}