Fragment For Image Viewer (android)

I'm trying to create a simple fragment that merely displays an image when clicked. I'm getting numerous errors inlcuding 'the method findViewbyId(int) is undefined for the type Exa

Solution 1:

findViewById is a method in the class Activity. To avoid passing an instance of the entire activity use a WeakRefence (see http://developer.android.com/reference/java/lang/ref/WeakReference.html) for example

private WeakReference<MainActivity> activity;

publicExampleFragment(MainActivity mainActivity) {
   activity = newWeakReference<MainActivity>(mainActivity);
} 

@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
    ImageViewimageview= (ImageView)activity.findViewById(R.id.imageView1);
    return Inflater.inflate(R.layout.iamgeview_main, container, false);
}

Solution 2:

I added the following modifications to your code ;

1) Import Fragment from support library(important if running on early versions of android);

2) Insted of Inflater I used the inflater received as method param;

3) I created a method findViewById that can be used in this fragment;

4) I moved some of the initialisation code in the method onActivityCreated ; Here

you cand find more about that method ;

package com.example.gctest;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup; 
import android.view.View.OnClickListener;
import android.webkit.WebView.FindListener;
import android.widget.Button;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;

import android.widget.ImageView;

publicclassExampleFragmentextendsFragment {

Button button;
ImageView image;


publicExampleFragment() {

}

publicstaticExampleFragmentnewInstance() {
    returnnewExampleFragment();
}

@OverridepublicViewonCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

        //ImageView imageview = (ImageView)findViewById(R.id.imageView1); this will raise NullPointerException because the parent view has not been created. Is is created with this method;return inflater.inflate(R.layout.iamgeview_main, container, false); //just return the  view ;
    }

@OverridepublicvoidonActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub//here you can initialise your variables,listeners,e.t.c ;super.onActivityCreated(savedInstanceState);

        ImageView imageview = (ImageView)findViewById(R.id.imageView1);
        addListenerOnButton();
    }

/**
 * You can use this method in order to access the child views of the fragment parent view;
 * @paramid
 * @return
 */protectedViewfindViewById(int id)
{
    returngetView().findViewById(id);
}

publicvoidaddListenerOnButton() {


    button = (Button) findViewById(R.id.btnChangeImage);
    button.setOnClickListener(newOnClickListener() {

        @OverridepublicvoidonClick(View arg0) {
            image.setImageResource(R.drawable.eagle);
        }

    });

}