Agfdhyk

I am new in Android Studio and I just started my first app.
my app is crashing from an unknown reason, hope you will help me to fix it

--------- beginning of crash

E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.ronz2.myfirstapp, PID: 3096

java.lang.ClassCastException: android.support.constraint.ConstraintLayout cannot be cast to android.widget.EditText

    at com.example.ronz2.myfirstapp.MainActivity$1.onClick(MainActivity.java:21)

    at android.view.View.performClick(View.java:6597)

    at android.view.View.performClickInternal(View.java:6574)

    at android.view.View.access$3100(View.java:778)

    at android.view.View$PerformClick.run(View.java:25885)

    at android.os.Handler.handleCallback(Handler.java:873)

    at android.os.Handler.dispatchMessage(Handler.java:99)

    at android.os.Looper.loop(Looper.java:193)

    at android.app.ActivityThread.main(ActivityThread.java:6669)

    at java.lang.reflect.Method.invoke(Native Method)

    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

This is the MainActivity code:

@Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);



    Button addBtn = (Button) findViewById(R.id.addBtn);

    addBtn.setOnClickListener(new View.OnClickListener() {

        @Override

        public void onClick(View v) {

            EditText firstNumEditText = (EditText) findViewById(R.id.firstNumEditText);

            EditText secondNumEditText = (EditText) findViewById(R.id.secondNumEditText);

            TextView resultTextView = (TextView) findViewById(R.id.resultTextView);



           int num1 = Integer.parseInt(firstNumEditText.getText().toString());

           int num2 = Integer.parseInt(secondNumEditText.getText().toString());

           int result = num1 + num2;



           resultTextView.setText(result + "");

        }

    });

}

If this is the only relevant code then one of these ids: firstNumEditText or secondNumEditText does not belong to an EditText but to a ConstraintLayout.



So one of these lines:

EditText firstNumEditText = (EditText) findViewById(R.id.firstNumEditText);

EditText secondNumEditText = (EditText) findViewById(R.id.secondNumEditText);

throws the exception, because you are trying to cast a ConstraintLayout to an EditText.


Check any ConstraintLayout's id in your xml that matches with these 2 ids and change it.