CODEWITHSUNDEEP
androidbaseadaptergetview
Bhavin Chowksi
Bhavin Chowksi

Reputation: 103

Android custom adapter getView() NullPointerException

I am trying to create a grid view which has an Imageview.I tried to extend BaseAdapter but i struck with the problem ,I will be glad if someone can point out the mistake i am doing.

Logcat:

07-10 19:29:00.881: D/AndroidRuntime(1678): Shutting down VM
07-10 19:29:00.881: W/dalvikvm(1678): threadid=1: thread exiting with uncaught exception (group=0xb3a47b90)
07-10 19:29:00.901: E/AndroidRuntime(1678): FATAL EXCEPTION: main
07-10 19:29:00.901: E/AndroidRuntime(1678): Process: com.shrek.try2, PID: 1678
07-10 19:29:00.901: E/AndroidRuntime(1678): java.lang.NullPointerException
07-10 19:29:00.901: E/AndroidRuntime(1678):     at com.shaastra.try2.MainActivity$lAdapter.getView(MainActivity.java:80)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.AbsListView.obtainView(AbsListView.java:2263)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.GridView.onMeasure(GridView.java:1044)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.View.measure(View.java:16458)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:719)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:455)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.View.measure(View.java:16458)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.View.measure(View.java:16458)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.View.measure(View.java:16458)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2289)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.View.measure(View.java:16458)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1914)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1111)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1293)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5582)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.Choreographer.doCallbacks(Choreographer.java:562)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.Choreographer.doFrame(Choreographer.java:532)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.os.Handler.handleCallback(Handler.java:733)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.os.Handler.dispatchMessage(Handler.java:95)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.os.Looper.loop(Looper.java:137)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at android.app.ActivityThread.main(ActivityThread.java:4998)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at java.lang.reflect.Method.invokeNative(Native Method)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at java.lang.reflect.Method.invoke(Method.java:515)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
07-10 19:29:00.901: E/AndroidRuntime(1678):     at dalvik.system.NativeStart.main(Native Method)

Its shows nullpointexception at line 80 (mainactivity and customadapter are defined in mainAcitivity.java) :

mainActivity.java:

package com.shrek.try2;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class MainActivity extends Activity{// implements     OnItemClickListener {

    GridView myGrid;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    myGrid = (GridView) findViewById(R.id.gridView);
    myGrid.setAdapter(new lAdapter(this));
}

class lAdapter extends BaseAdapter
{
    private final int[] lectimages={R.drawable.image_1,R.drawable.image_2,R.drawable.image_3,R.drawable.image_4,R.drawable.image_5,R.drawable.image_6,R.drawable.image_7,R.drawable.image_8,R.drawable.image_9};
    Context c;
    lAdapter(Context c)
    {
        this.c = c;
    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return lectimages.length;
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return 0;
    }


    @Override
    public View getView(int i, View convertView, ViewGroup parent)     {
        // TODO Auto-generated method stub
        View item;
            LayoutInflater inflater=(LayoutInflater) c.getSystemService(c.LAYOUT_INFLATER_SERVICE);
            item = inflater.inflate(R.layout.single_item, parent, false);
            ImageView lect = (ImageView) findViewById(R.id.imageView_1);
            lect.setImageResource(lectimages[i]);
        return item;

    }

}
}

Which means line lect in getView method is null, hence findviewbybyid is returning null but I have taken correct id, images have been added to drawable and exact layout(single_item.xml) has been inflated :

single_item.xml 

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

<ImageView
    android:id="@+id/imageView_1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_launcher"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:contentDescription="imageViewDescription"/>
</RelativeLayout>

and activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<GridView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/gridView"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:numColumns="auto_fit"
    android:horizontalSpacing="0dp"
    android:verticalSpacing="0dp"
    android:columnWidth="120dp"
    android:stretchMode="spacingWidthUniform"
    />

</RelativeLayout>

Please please help me, I am stuck in this problem for about 10 hours already.

Upvotes: 0

Views: 2671

Answers (1)

JafarKhQ
JafarKhQ

Reputation: 8734

lect is null, because you use findViewById(R.id.imageView_1), this will search for imageView_1 in your Activity Layout and return null if its not found.

And while your ImageView are in your ItemView, you have to find it in your itemView using View.findViewById() like this. 

item.findViewById(R.id.imageView_1);

Upvotes: 2

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