title: Accept decimals numbers with comma and dot
body: <p>I'm developing a uwp app, where I have a textbox, which I want to accept only decimals, comma or dot (for example: 1.5 or 1.5 or 1.50 or 1.50)
  With the value entered in this textbox, and after clicking a button in the app will do an operation:</p>
  
  <pre><code>double value= Convert.ToDouble(inputBox.Text);
  </code></pre>
  
  <p>InputBox is my textbox where the user enters the numbers.
  If I enter for example 1,50 does not give error, and does the operation I want. If I enter 1.50 it gives this error, in this line of code I presented:</p>
  
  <pre><code>System.FormatException was unhandled by user code
  Message=Input string was not in a correct format.
  </code></pre>