Tagged: Windows8

Single Decimal Point

Among the first issues I encountered when working on a windows phone application was the simple, plain textbox. This apparently friendly control has a dark side in a particular use case. When the InputScope is set to Numerical, it allows entering multiple decimal points.


In my case, I didn’t needed this “feature”. The best solution I could find to limit the decimal point to one, or none, was to develop an attached behavior.

You can find the complete solution here.

Below is the behavior’s structure:


The attached property IsDecimalPointAllowed will set the behavior to allow one or zero decimal points in the input.

public static readonly DependencyProperty IsDecimalPointAllowedProperty =
DependencyProperty.RegisterAttached("IsDecimalPointAllowed", typeof(bool?), typeof(DecimaPointBehavior), new PropertyMetadata(null, OnIsDecimalPointAllowedChanged));

public static bool? GetIsDecimalPointAllowed(DependencyObject obj)
  return (bool?)obj.GetValue(IsDecimalPointAllowedProperty);

public static void SetIsDecimalPointAllowed(DependencyObject obj, bool? value)
  obj.SetValue(IsDecimalPointAllowedProperty, value);

When the attached property is set to true or false, the value of the regex is established.

  • For limiting the input to allow only one decimal point:
  • For limiting the input to block any decimal point:


When the text inside the textbox changes, the new value is matched against the established regex:

private static void textBox_TextChanged(object sender, TextChangedEventArgs e)
 var textBox = (TextBox)sender;
 var match = Regex.Match(textBox.Text, regex);
 if (!match.Success)
   textBox.Text = textBox.Text.Remove(textBox.Text.Length - 1);
   textBox.Select(textBox.Text.Length, 0);


For no decimal point allowed, set the IsDecimalPointAllowed to false:

<TextBox Height="100"
behaviors:DecimaPointBehavior.IsDecimalPointAllowed="False" />;


For one decimal point allowed, set the IsDecimalPointAllowed to true:

<TextBox Height="100"
behaviors:DecimaPointBehavior.IsDecimalPointAllowed="True" />;


Windows 8 Wireframes

Here’s a basic problem. I’m trying to design my first store application on Windows 8 and I could use some tools for creating the wireframes.

The catch is that I’ve been a Mac user for a while and I’m not sure about how an windows 8 store application should feel and act. I can count my experience with Windows 8 in hours. You’re wondering why a Mac user is developing an Windows 8 app and tries to create the wireframes on Mac OS? I’m asking myself the same question.

To my defence, I’ve been impressed with what OmniGraffle can do and I wanted to use it for the wireframes. I found a great stencil for windows 8.

I am aware of the benefits of designing an Windows store app directly on Windows, but I haven’t found any worthy alternative for OmniGraffle on Windows. If you have any suggestions, please feel free to comment.

As for the “feel and act” part of the problem, the Design guidance for Windows Store apps from MSDN was a good starting point for me.

Happy wireframing!