Question

How to check if a “.” has been input into a TextBox?

is it something like:

if (TextBox1.Text == ".")
{
    //Do something...
}

because when I do this, it seems to not check what is in the TextBox1 and just continue with the next line of code

Here is my code:

private void btnContinue1_Click(object sender, RoutedEventArgs e)
    {
        if (string.IsNullOrEmpty(HouseholdNoTextBox.Text))
        {
            textBlockError2.Visibility = Visibility.Collapsed;
            textBlockError1.Visibility = Visibility.Visible;                
        }
        if (HouseholdNoTextBox.Text.Length >= 3)
        {//checking to see if it has a length greater than 2
            textBlockError1.Visibility = Visibility.Collapsed; // collapse the first error box if it is visible
            textBlockError2.Visibility = Visibility.Visible; // and make visible the second
        }
        if (HouseholdNoTextBox.Text == ".")
        {
            textBlockError1.Visibility = Visibility.Visible;  
        }
        if (HouseholdNoTextBox.Text.Length <= 2 && HouseholdNoTextBox.Text.Length > 0)
        {
            textBlockError1.Visibility = Visibility.Collapsed;
            textBlockError2.Visibility = Visibility.Collapsed;
            NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
        }

I have also tried:

if (HouseholdNoTextBox.Text.Contains("."))
        {
            textBlockError1.Visibility = Visibility.Visible;  
        }

I have also tried:

private void btnContinue1_Click(object sender, RoutedEventArgs e)
    {
        string houseHoldNo = HouseholdNoTextBox.Text.ToString();

        if (string.IsNullOrEmpty(HouseholdNoTextBox.Text) || houseHoldNo.Contains(".")) // adding it here along with the first if statement
        {
            textBlockError2.Visibility = Visibility.Collapsed;
            textBlockError1.Visibility = Visibility.Visible;                
        }
    }

I have also tried:

private void btnContinue1_Click(object sender, RoutedEventArgs e)
{
string houseHoldNo = HouseholdNoTextBox.Text.ToString();

        if (string.IsNullOrEmpty(HouseholdNoTextBox.Text))
        {
            textBlockError2.Visibility = Visibility.Collapsed;
            textBlockError1.Visibility = Visibility.Visible;                
        }
        if (houseHoldNo.Contains("."))
        {
            textBlockError1.Visibility = Visibility.Visible;
        }
    }

and this above code does the same as the other.. it skips to the last if statement.

Answer 1

You can do this by checking for the “.”

if(TextBox1.Text.Contains("."))
{
//Do Something
}

And then handle the event TextBox.TextChanged and place the above code in it.