Button doesnt work java android

Question

android/java/eclipse - i have this java file:(Eight.java)

/**
 * 
 */
package com.apptemplate;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.hoerhager.christmas.R;

/**
     *
 */
public class Eight extends Activity {

    private  AdView adView;
    private Button btn81;
    private Intent intent;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.one);
         adView = (AdView)this.findViewById(R.id.adView);
         AdRequest adRequest = new AdRequest.Builder().build();
         adView.loadAd(adRequest);
  }



    private void initialiseUI()
    {
        btn81   = (Button)findViewById(R.id.button81);
        btn81.setOnClickListener((OnClickListener) this);
    }
     @Override
      public void onPause() {
        adView.pause();
        super.onPause();
      }

      @Override
      public void onResume() {
        super.onResume();
        adView.resume();
      }

      @Override
      public void onDestroy() {
        adView.destroy();
        super.onDestroy();
      }

        public void onClick(View v) 
        {
            if(v==btn81)
            {
                intent = new Intent(this,Eighta.class);
            }

            startActivity(intent);
        }

}

and this xml File: (eight.xml)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >



    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/eight" />

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        ads:adSize="SMART_BANNER"
        ads:adUnitId="@string/ads_unit_id" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="2.41"
        android:text="@string/text8" />

    <Button
        android:id="@+id/button81"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp"
        android:text="Preparation" />

</LinearLayout>

The button81 doesnt work, what is the error? I am new to work with Java. Its for a little android project for testing

you are not initializing your button, are you? – A.S. Dec 20 '13 at 13:53 — A.S., Dec 20 '13 at 13:53
are you getting an exception? if so, please provide logcat – Philipp Sander Dec 20 '13 at 13:53 — Philipp Sander, Dec 20 '13 at 13:53

score 1 · Answer 1 · answered Dec 20 '13 at 13:56

You missed to call your initialiseUI() function in onCreate() method:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.one);
     adView = (AdView)this.findViewById(R.id.adView);
     AdRequest adRequest = new AdRequest.Builder().build();
     adView.loadAd(adRequest);
     initialiseUI();
}

score 0 · Answer 2 · answered Dec 20 '13 at 13:55

You forgot to call you initialiseUI function in onCreate:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.one);
         adView = (AdView)this.findViewById(R.id.adView);
         AdRequest adRequest = new AdRequest.Builder().build();
         adView.loadAd(adRequest);
         initialiseUI();
  }

Harry · Answer 3 · 2013-12-20T14:03:18.577

Try this:

/**
 * 
 */
package com.apptemplate;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.hoerhager.christmas.R;

/**
     *
 */
public class Eight extends Activity implements OnClickListener{

    private  AdView adView;
    private Button btn81;
    private Intent intent;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.one);
        adView = (AdView)this.findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().build();
        adView.loadAd(adRequest);
        initialiseUI();
  }



    private void initialiseUI()
    {
        btn81   = (Button)findViewById(R.id.button81);
        btn81.setOnClickListener(this);
    }
     @Override
      public void onPause() {
        adView.pause();
        super.onPause();
      }

      @Override
      public void onResume() {
        super.onResume();
        adView.resume();
      }

      @Override
      public void onDestroy() {
        adView.destroy();
        super.onDestroy();
      }

        public void onClick(View v) 
        {
            if(v.getId()==R.id.button81)
            {
                intent = new Intent(this,Eighta.class);
            }

            startActivity(intent);
        }

}

CHANGES:

Now implements onclickListener
Call initialiseUI in "onCreate" method
initlialiseUI removed cast to onClickListener as it now implements onClickListener
onClick now uses the ID to test equality

score 0 · Answer 4 · edited May 23 '17 at 11:50

I think you forgot this implement, try as below:

public class Eight extends Activity implements OnClickListener {

Also your initialiseUI method it's not called. Try this instead:

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

    // call the method here
    initialiseUI();

}

Finally, change the setOnClickListener like:

btn81.setOnClickListener(this);  
// this "attach" your button to the Activity which 
// implements the onClickListener method.

And then, your OnClick method is wrong, see this answer, you have two ways to do it:

@Override
public void onClick(final View v) {
    if(v.getId() == R.id.button){ // do something }
}

// OR

@Override
public void onClick(final View v) {
    switch(v.getId()){
        case R.id.button:
              // do something
              break;
        case ...
    }
}

Hope this helps.

You can see he already imported as import android.view.View.OnClickListener; — Piyush, Dec 20 '13 at 13:58

score 0 · Answer 5 · answered Dec 20 '13 at 13:57

0

Put this in oncreate()

 btn81   = (Button)findViewById(R.id.button81);
        btn81.setOnClickListener((OnClickListener) this);

answered Dec 20 '13 at 13:57

keshav

3,235
1
16
22

score 0 · Answer 6 · answered Dec 20 '13 at 14:01

0

you haven't called initialiseUI() in onCreate() and also implement the Click interface. That should do the trick.

answered Dec 20 '13 at 14:01

Rakeeb Rajbhandari

5,043
6
43
74

Button doesnt work java android

6 Answers6