I am trying to display a listview whenever menuItem is pressed. I want to display custom layout , for that I need custom adapter for list view which isn't working properly and my app is crashing. I have 3-4 custom adapter in my android app which were working fine, but since when i added another one... the previous one also stopped working i dont know why!! I have also seen almost every question related to this on many forums but nothing works for me. Please help me where i am wrong..
Below is my code for menuItems..
@Override
public boolean onOptionsItemSelected(MenuItem menuItem){
switch (menuItem.getItemId()){
case R.id.settings:
Intent intent = new Intent(this, OpenSettings.class);
startActivity(intent);
break;
case R.id.debacha:
Intent intent1 = new Intent(AyahsDisplay.this,DebachaDisplay.class);
this.startActivity(intent1);
break;
}
return super.onOptionsItemSelected(menuItem);
}
when menu item with id "debacha" is pressed, I am starting new activity in which I am intended to display custom listview where i am getting error and app crashes..
Code for that part is below...
public class DebachaDisplay extends AppCompatActivity {
ListView list1;
ArrayList<debacha> debachas = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_debacha_display);
try {
parseXML(); //here i am parsing XML file to load data in "debachas" which is working fine
} catch (XmlPullParserException e) { }
catch (IOException e) { }
}
private void printDebacha(ArrayList<debacha> debachas){
list1 = findViewById(R.id.debachaList);
CustomDebachaview customDebachaview = new CustomDebachaview(DebachaDisplay.this,debachas);
list1.setAdapter(customDebachaview);
}
Below is layout file for DisplayDebacha activity
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".DebachaDisplay">
<ListView
android:id="@+id/debachaList"
android:background="#FDFFE9"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
</ListView>
</LinearLayout>
Below is the code for my Custom adaptor class...
package com.example.demo;
import android.app.Activity;
import android.content.Intent;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import java.util.ArrayList;
public class CustomDebachaview extends ArrayAdapter<debacha> {
private ArrayList<debacha> debachas;
private Activity context;
public CustomDebachaview(Activity context,ArrayList<debacha> debachas){
super(context,R.layout.debacha_list_view,debachas);
this.debachas = debachas;
this.context = context;
}
@NonNull
@Override
public View getView(final int position , @Nullable View convertView , @Nullable final ViewGroup parent){
View r = convertView;
CustomDebachaview.viewHolder viewHolder = null;
if(r == null){
LayoutInflater layoutInflater = context.getLayoutInflater();
r = layoutInflater.inflate(R.layout.debacha_list_view,null,true);
viewHolder = new CustomDebachaview.viewHolder(r);
r.setTag(viewHolder);
}
else {
viewHolder = (CustomDebachaview.viewHolder) r.getTag();
}
viewHolder.Dnumber.setText("﴾ " + debachas.get(position).getDNumber() + " ﴿");
viewHolder.Dname.setText(debachas.get(position).getDName());
return r;
}
class viewHolder{
TextView Dnumber;
TextView Dname;
viewHolder(View v){
Dname = v.findViewById(R.id.Dnumber);
Dname = v.findViewById(R.id.Dname);
}
}
}
Below is custom adapter list view layout file code...
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/Dnumber"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="debacha number"
android:paddingLeft="5dp"
android:textSize="17dp"
android:textColor="#297B16"
android:textStyle="bold"
/>
<TextView
android:id="@+id/Dname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Dname"
android:textSize="25dp"
android:textColor="#226A12"
/>
</LinearLayout>
I am getting following errors..
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.demo, PID: 1040
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.example.demo.CustomDebachaview.getView(CustomDebachaview.java:42)
at android.widget.AbsListView.obtainView(AbsListView.java:3219)
at android.widget.ListView.makeAndAddView(ListView.java:2219)
at android.widget.ListView.fillDown(ListView.java:827)
at android.widget.ListView.fillFromTop(ListView.java:888)
at android.widget.ListView.layoutChildren(ListView.java:1958)
at android.widget.AbsListView.onLayout(AbsListView.java:2991)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1812)
at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1801)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1567)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at androidx.appcompat.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:444)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1812)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1656)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1565)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at com.android.internal.policy.DecorView.onLayout(DecorView.java:1075)
at android.view.View.layout(View.java:22407)
at android.view.ViewGroup.layout(ViewGroup.java:6589)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:3371)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2840)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1888)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:8503)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:949)
at android.view.Choreographer.doCallbacks(Choreographer.java:761)
at android.view.Choreographer.doFrame(Choreographer.java:696)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:935)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7073)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:964)
I/Process: Sending signal. PID: 1040 SIG: 9
Process 1040 terminated.
Any help is highly appreciated :)
