I am currently developing a mobile app with Xamrin.Forms and I had to know the difference between two DateTime in hours. It seems dumb, but in fact, it is quite tough to find a smart and optimised way to do it. I wanted to share with you the solution I found.

Basics

First, let's look at the basics.

• DateTime.Substract(DateTime) lets us to substract the first date by the second one. It returns a TimeSpan value and it represents a time interval.
• TimeSpan is in fact, an instance that represents the difference between 2 DateTime objects. To learn more about this type, go here.
• TimeSpan.TotalHours is the property that interests us. It gets the value of the current TimeSpan structure expressed in whole and fractional hours and its value type is a double.
• If you need the hour difference without a fraction of hours by using TimeSpan.Hours property. It returns an int

Example

Here is a code snippet using this method to get the hour difference for training.

public int GetHourDifference(DateTime dateBefore, DateTime dateAfter)
{
  TimeSpan hourDifferenceSpan = dateAfter.Subtract(dateBefore);

  int hourDifference = hourDifferenceSpan.TotalHours;

  return hourDifference;
}

DateTime trainingBegin = DateTime.Today; // The training begins now
DateTime trainingEnd = DateTime.Today.AddHours(2);

Console.WriteLine("The training will last " + GerHourDifference(trainingBegin, trainingEnd) + " hours.");

Thank you so much for reading! I like to share all of those little tips! If you like it and it also interests you, please let me know in the comments! I can do these with JS, PHP, HTML and CSS. I will also try to create some little videos with tips like that. If you would like to see that, share it in the comments below. ✨

If you want to support me, you can always buy me a coffee.

Sources

• c# - How to get hours between two DateTimes
• TimeSpan Struct
• Photo by Icons8 Team on Unsplash

I was shocked, how long it took me to succeed in finding how to use the alpha layer in hexadecimal colors or hex colors in XAML. Well, turns out it is really simple.

Here is the official doc of Xamarin.Forms explaining how to use the hex colours in XAML.

<Label Text="Sea color" BackgroundColor="Aqua" />
<Label Text="RGB" BackgroundColor="#00FF00" />
<Label Text="Alpha plus RGB" BackgroundColor="#CC00FF00" />
<Label Text="Tiny RGB" BackgroundColor="#0F0" />
<Label Text="Tiny Alpha plus RGB" BackgroundColor="#C0F0" />

Pretty clear right? In fact, not at all. I come from the web world, so for me, when I use an alpha layer in a hex color it looks like this :

#RRGGBBAA // Where RR = red, GG = green, BB = blue and AA = alpha

The alpha layer is at the end of the hex. Note : the value of alpha is between 00 and 99. Turns out, the alpha layer in XAML is at the beginning. Here is the official doc, but with comments.

<Label Text="Sea color" BackgroundColor="Aqua" />
<Label Text="RGB" BackgroundColor="#CC00FF" />    <!-- #RRGGBB -->
<Label Text="Alpha plus RGB" BackgroundColor="#00CC00FF" />    <!-- #AARRGGBB -->
<Label Text="Tiny RGB" BackgroundColor="#CF0" /> <!-- #RGB -->
<Label Text="Tiny Alpha plus RGB" BackgroundColor="#0CF0" /> <!-- #ARGB -->

There is also another form of hex colours; scRGB formatted number. The format is sc#scA,scR,scG,scB where each value is between 0.0 to 1.0. I personally never tested it, but I wanted to share it with you all!

Thank you for reading! I hope you like it. If you have questions or if I said something wrong, don't hesitate to tell me in the comments! It is surprising sometimes how hex colors can have different formats depending of the language.

If you want to support me, you can always buy me a coffee.

Enjoy ✨

Sources

• #210 – Specifying Colors in XAML As RGB Values - By Sean Sexton
• Colors in Xamarin.Forms