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Android Build a Simple Android App Basic Android Programming Initializing a Button

Adia Gawhari
Adia Gawhari
1,378 Points
Posted by Adia Gawhari
Adia Gawhari
1,378 Points

How do you initialize the showFactButton?

Hi! For some reason my code isn't working. Can you spot anything wrong that might be the reason?

// Declare our View variables and assign them the Views from the layout file TextView factLabel = (TextView) findViewById(R.id.factTextView); Button showFactButton = (Button) findButtonById(R.id.showFactButton);

FunFactsActivity.java 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class FunFactsActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fun_facts);

        // Declare our View variables and assign them the Views from the layout file
        TextView factLabel = (TextView) findViewById(R.id.factTextView);
        Button showFactButton = (Button) findButtonById(R.id.showFactButton);
    }
}

1 Answer

Evan Demaris
Evan Demaris
64,262 Points
Evan Demaris
Evan Demaris
64,262 Points

Hi Adia,

You'd want to declare variables outside the onCreate method as below;

public class FunFactsActivity extends Activity {

    TextView factLabel;
    Button showFactButton;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fun_facts);

        // Declare our View variables and assign them the Views from the layout file
        factLabel = (TextView) findViewById(R.id.factTextView);
        showFactButton = (Button) findViewById(R.id.showFactButton);
    }
}

Declaring them outside the method allows for them to be changed by onCreate, and still be usable to any other methods you have in the FunFactsActivity class. If you were to re-declare the variable type inside onCreate, you'd be indicating that the variable being re-declared is actually a different one from the variable that was declared outside.

Also, please note that I changed the last line of your code from findButtonById to findViewById; the Button is still a View. Please let me know if you have any questions about that code or why it works!