Android App Keeps Crashing In Avd, But Is Built Properly In Gradle

I made this small android app with two buttons and a textview, pretty basic. But its not starting in the emulator. No build errors whatsoever. Here's the activity_main.xml file <

Solution 1:

You are trying to access **xml** instances before it get's created that's makes app causing to crashed.

To check the caused due to your app crashed you may refer to check Logcat into your IDE.

Put Your instantiation code inside onCreate() callback:-

package com.example.android.testapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

publicclassMainActivityextendsAppCompatActivity {

final TextView mShowCounter;
final Button button;
privateintmCount=0;

@OverrideprotectedvoidonCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mShowCounter = (TextView) findViewById(R.id.text_view_counter);
    button = (Button) findViewById(R.id.toast_button);
}


publicvoidshowToast(View view) {
    Toasttoast= Toast.makeText(this, 
R.string.toast_popup,Toast.LENGTH_LONG);
    toast.show();
}

publicvoidcounterUp(View view) {
    mCount++;
    if(mShowCounter != null) {
        mShowCounter.setText(Integer.toString(mCount));
    }
}
}

Solution 2:

Android app keeps crashing in AVD, but is built properly in Gradle

Because you are doing findViewById outside onCreate() without doing setContentView()

Do findViewById inside onCreate() method after setContentView()

Declare your TextView mShowCounter and Button button; as Global

SAMPLE CODE

publicclassMainActivityextendsAppCompatActivity {

 TextView mShowCounter ;
 Button button  ;
privateintmCount=0;

@OverrideprotectedvoidonCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
     mShowCounter = (TextView) findViewById(R.id.text_view_counter);
     button = (Button) findViewById(R.id.toast_button);
}


publicvoidshowToast(View view) {
    Toasttoast= Toast.makeText(this, 
R.string.toast_popup,Toast.LENGTH_LONG);
    toast.show();
}

publicvoidcounterUp(View view) {
    mCount++;
    if(mShowCounter != null) {
        mShowCounter.setText(Integer.toString(mCount));
    }
}
}

Solution 3:

The problem lies in these lines.

finalTextViewmShowCounter= (TextView) findViewById(R.id.text_view_counter);
finalButtonbutton= (Button) findViewById(R.id.toast_button);

Your app crashes because during the class init phase, the Views don't exist yet. findViewById will not work.

You should instead move these lines inside onCreate.

Solution 4:

Your component initializations should go in the onCreate() i.e put your

mShowCounter = (TextView) findViewById(R.id.text_view_counter);button = (Button) findViewById(R.id.toast_button);

inside of onCreate().