It has become to sort-of standard way to avoid the findViewById usage.

Particularly, the Butterknife library created by Jake Wharton has become super famous and has got huge interest by developers around the world. Many different libraries have tried to simplify the findViewById() usage with different methods. Languages: Supports both Java and Kotlin. You have to declare a separate variable for all the views you need from XML layouts. You will have to check views before accessing for null values.īoilerplate Code: A lot. Type-safe: Before API 26, there was no type-safety.

This may give you NullPointerException if you are not checking your views for null-safety, but this method will not throw ClassCastException like it used to. If you are referencing a Button with a TextView ID, then Android SDK will try to find the Button with the provided ID and it will return NULL because it won’t be able to find it.īut in Kotlin, you would still need to provide the type like findViewById(R.id.txtUsername). Now, developers don’t need to cast their views manually in the code. In the API level 26 of compileSdk, the definition of this method was slightly changed to remove the casting issue.

This method was used extensively and is being used as well throughout whole evolution of Android SDK. Instead you will get ClassCastException as a TextView cannot be converted to Button. If the view is TextView in XML layout and you are type-casting it as Button, you won’t get any compile time errors. Rather you will get NullPointerException at runtime when Android fails to locate the view in Activity, Fragment or ViewGroup. If there is view with this ID in this layout, you won’t get any compile time errors. There are some problems with this approach. Introduced in the API level 1, this requires an ID and returns a View object. Obviously, the first one is the findViewById() method. In this article, I am going to discuss on how the findViewById() evolved over time and what’s the best approach in “modern Android development” to get the view reference from XML layouts.

Butterknife android studio plugin