TEXTVIEW Click is not working in android

Question

package com.jd.multileveltreelistview;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MultilevelTreeListView extends Activity 
{
    ListAdapter adapter;
    ListView mainList;
    ArrayList<Entity>arrTrades;
    public static int totcnt = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.treelist);
        mainList=(ListView)findViewById(R.id.currentpending_list);
        mainList.setDividerHeight(4);
        arrTrades=new ArrayList<Entity>();

        try {
        TextView textview = (TextView) findViewById(R.id.row_cell_text_multilevel);
        textview.setOnClickListener(new View.OnClickListener() {

                    @Override
                    public void onClick(View arg0) {
                        // TODO Auto-generated method stub
                        Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show(); 
                        }
                 });
        } catch(Exception e) { }
    }

    @Override
    protected void onResume() 
    {
        if(arrTrades.size()==0){
            populateList();
        }
        super.onResume();
    }

    public Entity getEntity(int level,int haschild){
        Entity E=new Entity();
        E.Name="Level "+level;
        E.Name= " S.Viswanathan " + totcnt + "\n";
        E.Name = E.Name + "Role: Group Leader " + "\n";
        E.Name = E.Name + "Mail: s.vishy@tcscom " + "\n";
        E.Name = E.Name + "Phone:  9600421518";
        totcnt = totcnt + 1;
        E.isOpened=false;
        E.level=level;
        E.HasChild=haschild;
        return E;
    }
    public void populateList()
    {
        try
        {
            for(int i=0;i<1;i++){
                    arrTrades.add(getEntity(0, 1));
            }
            adapter=new ListAdapter(MultilevelTreeListView.this, R.id.row_cell_text_multilevel, arrTrades);
            mainList.setAdapter(adapter);
        }
        catch (Exception e)
        {
            Log.d(" populateList Exception",""+e.getMessage());
        }
    }

    public void CellTextClick()
    {
        Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show();
    }
    public void CellButtonClick(View v){
        try{
            Toast.makeText(getApplicationContext(), "Button Clicked : " , Toast.LENGTH_SHORT).show();
            Button b=(Button)v;
            int index;
            index=(Integer) b.getTag();
            if(b.getText().toString().equals("+")){
                b.setText("-");
                Entity temp[]=new Entity[5];
                int PLevel=arrTrades.get(index).level+1;
                for(int i=0;i<5;i++){
                    temp[i]=getEntity(PLevel, 1);
                }
                arrTrades.get(index).isOpened=true;
                if(temp!=null){
                    int addindex=index+1;
                    for(int i=0;i<temp.length;i++){
                        arrTrades.add(addindex, temp[i]);
                        addindex++;
                    }
                }
                temp=null;
            }
            else{
                b.setText("+");
                arrTrades.get(index).isOpened=false;
                    int removeindex=index+1;
                    for(int i=0;i<5;i++){
                        if(arrTrades.get(removeindex).isOpened){
                            removeChilds(removeindex);
                        }
                        arrTrades.remove(removeindex);
                    }
                }


            adapter.notifyDataSetChanged();
        }
        catch(Exception e){
            adapter.notifyDataSetChanged();
            Log.d("Error=", ""+e.getMessage());
        }
    }
    public void removeChilds(int index){
        try {
                int removeindex=index+1;
                for(int i=0;i<5;i++){
                    if(arrTrades.get(removeindex).isOpened){
                        removeChilds(removeindex);
                    }
                    arrTrades.remove(removeindex);
                }
        } catch (Exception e) {
            // TODO: handle exception
            Log.d("Errro=", ""+e.getMessage());
        }
    }
}

ERROR:

02-25 11:34:50.965: E/AndroidRuntime(6907): Uncaught handler: thread main exiting due to uncaught exception
02-25 11:34:50.980: E/AndroidRuntime(6907): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.jd.multileveltreelistview/com.jd.multileveltreelistview.MultilevelTreeListView}: java.lang.NullPointerException
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread.access$2200(ActivityThread.java:119)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.os.Looper.loop(Looper.java:123)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread.main(ActivityThread.java:4363)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at java.lang.reflect.Method.invokeNative(Native Method)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at java.lang.reflect.Method.invoke(Method.java:521)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:862)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:620)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at dalvik.system.NativeStart.main(Native Method)
02-25 11:34:50.980: E/AndroidRuntime(6907): Caused by: java.lang.NullPointerException
02-25 11:34:50.980: E/AndroidRuntime(6907):     at com.jd.multileveltreelistview.MultilevelTreeListView.onCreate(MultilevelTreeListView.java:29)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-25 11:34:50.980: E/AndroidRuntime(6907):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
02-25 11:34:50.980: E/AndroidRuntime(6907):     ... 11 more

I want user perform some activities on Textview Click, but that part is not invoked properly in my program.Please see the XML File, Java Program and also the particular function of clickable event.

XML File:

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="40dp"
    android:background="#ffffff"
    android:orientation="horizontal"
    android:gravity="center"

        android:id="@+id/row">
           <HorizontalScrollView 
            android:id="@+id/scrollview"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" 
            android:fillViewport="true"
            android:scrollbars="none">
            <LinearLayout 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView 
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_marginLeft="0dp"
        android:textSize="10dp"
        android:textColor="#ffffff"
        android:id="@+id/row_cell_text_dummy_multilevel"
        android:singleLine="false"  />
    <Button 
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:id="@+id/row_cell_btn_multilevel"
        android:onClick="CellButtonClick"

        android:layout_marginLeft="5dp"
        android:layout_marginTop="5dp"
        android:layout_marginBottom="5dp"/>
    <TextView 
        android:layout_height="fill_parent"
        android:layout_width="fill_parent"
        android:layout_marginLeft="7dp"
        android:textSize="10dp"
        android:clickable="true"
        android:onClick="CellTextClick"
        android:textColor="#000000"
        android:layout_weight="4"
        android:singleLine="false"
        android:gravity="center|left"/>
      </LinearLayout> 
      </HorizontalScrollView>
</LinearLayout>

I want user to click the Text view also, so that i can do some function. But the below module in the program is not called.Java Program which contains the above code, the CellTextClick should be called in the below program, but its not invoked.

package com.jd.multileveltreelistview;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MultilevelTreeListView extends Activity 
{
    ListAdapter adapter;
    ListView mainList;
    ArrayList<Entity>arrTrades;
    public static int totcnt = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.treelist);
        mainList=(ListView)findViewById(R.id.currentpending_list);
        mainList.setDividerHeight(4);
        arrTrades=new ArrayList<Entity>();
    }

    @Override
    protected void onResume() 
    {
        if(arrTrades.size()==0){
            populateList();
        }
        super.onResume();
    }

    public Entity getEntity(int level,int haschild){
        Entity E=new Entity();
        E.Name="Level "+level;
        E.Name= " S.Viswanathan " + totcnt + "\n";
        E.Name = E.Name + "Role: Group Leader " + "\n";
        E.Name = E.Name + "Mail: s.vishy@tcscom " + "\n";
        E.Name = E.Name + "Phone:  9600421518";
        totcnt = totcnt + 1;
        E.isOpened=false;
        E.level=level;
        E.HasChild=haschild;
        return E;
    }
    public void populateList()
    {
        try
        {
            for(int i=0;i<1;i++){
                    arrTrades.add(getEntity(0, 1));
            }
            adapter=new ListAdapter(MultilevelTreeListView.this, R.id.row_cell_text_multilevel, arrTrades);
            mainList.setAdapter(adapter);
        }
        catch (Exception e)
        {
            Log.d(" populateList Exception",""+e.getMessage());
        }
    }

    public void CellTextClick(View v)
    {
        Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show();
    }

    public void CellButtonClick(View v){
        try{
            Toast.makeText(getApplicationContext(), "Button Clicked : " , Toast.LENGTH_SHORT).show();
            Button b=(Button)v;
            int index;
            index=(Integer) b.getTag();
            if(b.getText().toString().equals("+")){
                b.setText("-");
                Entity temp[]=new Entity[5];
                int PLevel=arrTrades.get(index).level+1;
                for(int i=0;i<5;i++){
                    temp[i]=getEntity(PLevel, 1);
                }
                arrTrades.get(index).isOpened=true;
                if(temp!=null){
                    int addindex=index+1;
                    for(int i=0;i<temp.length;i++){
                        arrTrades.add(addindex, temp[i]);
                        addindex++;
                    }
                }
                temp=null;
            }
            else{
                b.setText("+");
                arrTrades.get(index).isOpened=false;
                    int removeindex=index+1;
                    for(int i=0;i<5;i++){
                        if(arrTrades.get(removeindex).isOpened){
                            removeChilds(removeindex);
                        }
                        arrTrades.remove(removeindex);
                    }
                }


            adapter.notifyDataSetChanged();
        }
        catch(Exception e){
            adapter.notifyDataSetChanged();
            Log.d("Error=", ""+e.getMessage());
        }
    }
    public void removeChilds(int index){
        try {
                int removeindex=index+1;
                for(int i=0;i<5;i++){
                    if(arrTrades.get(removeindex).isOpened){
                        removeChilds(removeindex);
                    }
                    arrTrades.remove(removeindex);
                }
        } catch (Exception e) {
            // TODO: handle exception
            Log.d("Errro=", ""+e.getMessage());
        }
    }
}

Answer 1

Give id to your textview
XML:-

<TextView 
                android:id="@+id/txt"
                android:layout_height="fill_parent"
                android:layout_width="fill_parent"
                android:layout_marginLeft="7dp"
                android:textSize="10dp"
                android:textColor="#000000"
                android:layout_weight="4"
                android:singleLine="false"
                android:gravity="center|left"/>

Activity:

TextView tv1 = (TextView) findViewById(R.id.txt);
tv1.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
switch(v.getId()){
case R.id.txt:
    Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show();
    break;

default:
    break;
                }
       }
});

Hope it will work !!

Updated Answer:--

Write this,

TextView tv1 = (TextView) findViewById(R.id.row_cell_text_dummy_multilevel);

instead of this

 TextView textview = (TextView) findViewById(R.id.row_cell_text_multilevel);

As you had give your button id to your textView, thats why you are getting null pointer exception...

Answer 2

Try to give an id to the textview and try again or Try this:

TextView tv1 = (TextView) findViewById(R.id.tv1);
tv1.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
   Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show();
});

Answer 3

Add id to the textview

<TextView 
        android:id="@+id/textview01"
        android:layout_height="fill_parent"
        android:layout_width="fill_parent"
        android:layout_marginLeft="7dp"
        android:textSize="10dp"
        android:clickable="true"
        android:onClick="CellTextClick"
        android:textColor="#000000"
        android:layout_weight="4"
        android:singleLine="false"
        android:gravity="center|left"/>

And add onclick listener

TextView textview = (TextView) findViewById(R.id.textview01);
textview.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                    System.out.println("Text clicked");

            }
        });

Answer 4

try it out

    Textview tv;
  tv=(TextView)findViewById(R.id.row_cell_text_dummy_multilevel);
    tv.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            toast();

        }

        private void toast() {
            // TODO Auto-generated method stub
            Log.i("click", "sucss");
        }
    });

Answer 5

Try this

TextView textview = (TextView) findViewById(R.id.yourid);
    textview.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub

                    }
            });

Answer 6

try following

<TextView
    android:id="@+id/tv1" 
    android:layout_height="fill_parent"
    android:layout_width="fill_parent"
    android:layout_marginLeft="7dp"
    android:textSize="10dp"
    android:clickable="true"
    android:textColor="#000000"
    android:layout_weight="4"
    android:singleLine="false"
    android:gravity="center|left"/>

Activity

TextView tv1 = (TextView) findViewById(R.id.tv1);
tv1.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
switch(v.getId()){
case R.id.tv1:
    Toast.makeText(getApplicationContext(), "Answer As of Now : " , Toast.LENGTH_SHORT).show();
    break;

default:
    break;
                }
       }
});