Let’s learn how to create custom dialog in android and while we are at it, let us also do simple validation of the data the user entered before clicking the OK button! What is an alert dialog in android? It is a small window that asks a user to make a decision or enter more information in an app. You have probably seen a lot of them if you have used android apps in your smartphone. Anyway, the reason why I am showing you how to create custom dialog is because sometimes you may wish to have a different looking dialog box than what comes with your sdk and more importantly, you may wish to validate the data – without using your own custom dialog, it can be tricky …but not anymore! Let us take a look!