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Android

Posted by curtis Christie
curtis Christie
1,811 Points

Coding the Fun Facts

I am currently going through the android videos and I have created the if statements but the statements aren’t coming up on my emulator, can't get my head around this can anybody help and explain where i am going wrong ?

This is my code 

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

        //declare are View variables and assign the views from the layout file
        final TextView factLabel = (TextView) findViewById(R.id.factTextView);

        Button showFactButton = (Button) findViewById(R.id.showFactButton);
        View.OnClickListener Listener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            //the button was clicked, so update the fact label with a new fact
                String fact = "";
                // randomly select a fact
                Random randomGenerator = new Random();//construct a new random generator
                int randomNumber = randomGenerator.nextInt(3);

                /*Convert the randomNumber to a text fact
                    * 0 = Have a bath everyday
                    * 1 = Read a book once a month
                    * 2 = Always strive to be the best
                 */

                     // if randomNumber equals 0 then set fact equal to Have fact
                     if (randomNumber == 0){
                        fact = "Have a bath everyday";
                     }
                    // if  randomNumber equals 1 then set fact equal to Read fact
                   else if (randomNumber == 1){
                    fact = "Read a book once a month";
                     }

                     // if  randomNumber equals 2 then set fact equal to Always fact
                    else if (randomNumber == 2){
                    fact = "Always strive to be the best";
                    }

                    else{

                         fact = "sorry there was an error";
                     }

                //update the label with our dynamic fact
                         factLabel.setText(fact);
            }
        };
        showFactButton.setOnClickListener(Listener);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_fun_facts, menu);
        return true;
    }

1 Answer

faraz
faraz
Courses Plus Student 21,474 Points

You are implementing your button's onClickListener wrong. This is one of many ways an onClickListener is setup:

public class MyActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.mylayout);
        findViewById(R.id.button1).setOnClickListener(mButton1_OnClickListener);
    }   

    // OnClickListener for button1
    final OnClickListener mButton1_OnClickListener = new OnClickListener() {
        public void onClick(final View v) {
            //Inform the user the button has been clicked
            Toast.makeText(this, "Button1 clicked.", Toast.LENGTH_SHORT).show();                
        }
    };
}

Another way (my personal favorite): 

findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        //Inform the user the button has been clicked
        Toast.makeText(this, "Button1 clicked.", Toast.LENGTH_SHORT).show();  
    }
});

Or by using an onClick reference for the button in XML:

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/button1"
            android:onClick="button1OnClick"/>

and then simply doing this:

//On click event for button1
public void button1OnClick(View v) {
    //Inform the user the button has been clicked
    Toast.makeText(this, "Button1 clicked.", Toast.LENGTH_SHORT).show();                
}

Read this tutorial for more information on how to correctly implement an onClickListener. Hope that helps! Let me know if you have any other questions. :)

curtis Christie
curtis Christie
1,811 Points

Thanks for the information i have decided to add the following to the xml document android:onClick="buttonClick"/>

This is the code i now have in my xml document :

<Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Show Another Fun Fact " android:id="@+id/showFactButton" android:layout_gravity="center_horizontal|bottom" android:background="#ffffffff" android:onClick="buttonClick"/>

Numbers are still not coming up where am i going wrong , i know that i am close but can someone explain please ?

this is my code 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);
    Button button = (Button) findViewById(R.id.showFactButton);

    button.setOnClickListener(
       new Button.OnClickListener() {
           public void onClick(View v) {
             TextView factTextView =
                     (TextView)findViewById(R.id.factTextView);
             factTextView.setText("button clicked ");



           }
       }
    );

    //declare are View variables and assign the views from the layout file
    final TextView factLabel = (TextView) findViewById(R.id.factTextView);



    View.OnClickListener Listener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        //the button was clicked, so update the fact label with a new fact
            String fact = "";
            // randomly select a fact
            Random randomGenerator = new Random();//construct a new random generator
            int randomNumber = randomGenerator.nextInt(3);

            /*Convert the randomNumber to a text fact
                * 0 = Have a bath everyday
                * 1 = Read a book once a month
                * 2 = Always strive to be the best
             */
                 // if randomNumber equals 0 then set fact equal to Have fact
                 if (randomNumber == 0){
                    fact = "Have a bath everyday";


                 }
                // if  randomNumber equals 1 then set fact equal to Read fact
               else if (randomNumber == 1){
                fact = "Read a book once a month";


                 }

                 // if  randomNumber equals 2 then set fact equal to Always fact
                else if (randomNumber == 2){
                fact = "Always strive to be the best";


                }

                else{

                     fact = "sorry there was an error";
                 }

            //update the label with our dynamic fact
                     factLabel.setText(fact);
        }
    };

}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_fun_facts, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

}