CODEWITHSUNDEEP
androidandroid-layoutfindviewbyid
Mango
Mango

Reputation: 51

GridLayout gridLayout = findViewById(R.id.gridLayout); crashes my app

Whenever I want to find my grid layout by ID my app crashes immediately upon starting. It is not a typo (I don't get any compiling errors).

It is the first thing I have declared in onCreate method so it doesn't crash because some other method would try to do something with the layout before the findViewById is called.

What could be the cause?

(I tried changing its ID, name... didn't work)

Part of the code:

public class MainActivity extends AppCompatActivity {

TextView countdownView, expressionView, scoreView, resultView, goView;
LinearLayout linearLayout;
GridLayout gridLayout;
CountDownTimer countDownTimer;
Random randomGenerator;
Button startGameButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    gridLayout = findViewById(R.id.gridLayout);
    //other code here}

Upvotes: 2

Views: 2172

Answers (5)

Gyan Jyoti Das
Gyan Jyoti Das

Reputation: 397

replace your line by this 

androidx.gridlayout.widget.GridLayout gridLayout = findViewById(R.id.gridLayout);

Upvotes: 4

Prashant Bastodkar
Prashant Bastodkar

Reputation: 1

findViewbyId is changed in android studio 3.*

refer

findViewById() signature change All instances of the findViewById() method now return <T extends View> T instead of View. This change has the following implications:

This may result in existing code now having ambiguous return type, for example if there is both someMethod(View) and someMethod(TextView) that takes the result of a call to findViewById(). When using Java 8 source language, this requires an explicit cast to View when the return type is unconstrained (for example, assertNotNull(findViewById(...)).someViewMethod()). Overrides of non-final findViewById() methods (for example, Activity.findViewById()) will need their return type updated.

EditText message=super.findViewById(R.id.txtmessage);

I am a new android learner. Directly trying codes of videos in my learning

Upvotes: 0

Mango
Mango

Reputation: 51

I had to change casting from this:

GridLayout gridLayout = findViewById(R.id.gridLayout);

To this:

android.support.v7.widget.GridLayout gridLayout = findViewById(R.id.gridLayout);

Upvotes: 2

A.El Saeed
A.El Saeed

Reputation: 99

Change it

from 

gridLayout = findViewById(R.id.gridLayout);

to

gridLayout = (GridLayout) findViewById(R.id.gridLayout);

You should cast the result from findViewById function

Upvotes: -3

rajat singh
rajat singh

Reputation: 195

Either cast it like A.El Saeed mentioned in his answer 

gridLayout = (GridLayout)findViewById(R.id.gridLayout);

or post your XML code also because sometime, it may possible that there will be some typo in your XML code or maybe you are using different grid layout id than defined in the XML

Upvotes: -2

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