Eric Zhao Eric Zhao - 29 days ago 10
Android Question

No need to cast the result of findViewById?

Recently i found that AndroidStudio reminds me to remove some class cast. I remember that in the old time, we have to cast the result of findViewById, but now it's not necessary.

The result of findViewById is still View, so i want to know why we don't need to cast the class?

I can't find any documents mentioned that, can anyone find any document?

Answer Source

Starting with API 26, findViewById uses inference for its return type, so you no longer have to cast.

Old definition:

View findViewById(int id)

New definition:

<T extends View> T findViewById(int id)

So if your compileSdk is at least 26, it means that you can make use of this :)