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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
23,732 Points
Kourosh Raeen
Kourosh Raeen
23,732 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
23,732 Points
Kourosh Raeen
Kourosh Raeen
23,732 Points

Glad I could help! Happy coding!