Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

osvaldo gonzalez
osvaldo gonzalez
2,167 Points
Posted by osvaldo gonzalez
osvaldo gonzalez
2,167 Points

How to do this activity:Initialize the showFactButton variable using the findViewById() method like the TextView above i

Initialize the showFactButton variable using the findViewById() method like the TextView above it. The ID for the button is showFactButton, and don't forget to cast it to a Button with (Button)!

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 {

  private 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
        TextView factLabel = (TextView) findViewById(R.id.factTextView);
        Button showFactButton;
    }
}
osvaldo gonzalez
osvaldo gonzalez
2,167 Points
osvaldo gonzalez
osvaldo gonzalez
2,167 Points

is the next line that I need to add?
private Button showFactButton;

1 Answer

Kourosh Raeen
Kourosh Raeen
23,733 Points
Kourosh Raeen
Kourosh Raeen
23,733 Points

showFactButton is already defined as a private member variable. You just need to get a reference to the button using its id and the findViewById method, cast it to a Button, and then assign it to the variable:

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) findViewById(R.id.showFactButton);
    }
}
Kourosh Raeen
Kourosh Raeen
23,733 Points
Kourosh Raeen
Kourosh Raeen
23,733 Points

Glad I could help! Happy coding!