Tengo un cronometro android(q lo programe yo debido a que necesito los milisegundos), donde al presionar un boton se registra el tiempo para corredores. cuando se presiona el boton el tiempo pasa a un listview que tiene un editext que espera recibir el numero del corredor, y actualizo el adapter.Mi problema es que el listview se pone mas lento a medida que voy agregando tiempos, y me va trabando el cronometro. si bien el tiempo continua la aplicacion no queda bien si el reloj se va trabando cada vez que marco un lap.Todos estos datos tienen que guardarse luego en una base de datos.

CLASE ADAPTER

public class ItemListAdapter extends ArrayAdapter { protected static final String LOG_TAG = ItemListAdapter.class.getSimpleName();

private ArrayList<Persona> items; private int layoutResourceId; private Context context;  public ItemListAdapter(Context context, int layoutResourceId, ArrayList<Persona> items) {     super(context, layoutResourceId, items);     this.layoutResourceId = layoutResourceId;     this.context = context;     this.items = items; }  @SuppressLint("ViewHolder") @Override public View getView(int position, View convertView, ViewGroup parent) {     View row = convertView;     Holder holder = null;      LayoutInflater inflater = ((Activity) context).getLayoutInflater();     row = inflater.inflate(layoutResourceId, parent, false);      holder = new Holder();     holder.bean = items.get(position);     //holder.ibDelete = (ImageButton)row.findViewById(R.id.ibDelete);     //holder.ibDelete.setTag(holder.bean);      holder.etVal1 = (EditText)row.findViewById(R.id.nrocompetidor);     //holder.etVal2 = (EditText)row.findViewById(R.id.edValue2);     holder.tvTotal=(TextView) row.findViewById(R.id.et_laps);      setVal1TextChangeListener(holder);     //setVal2TextListeners(holder);      row.setTag(holder);      setupItem(holder);      return row; }  private void setupItem(Holder holder) {     holder.etVal1.setText(String.valueOf(holder.bean.getNumero()));     //holder.etVal2.setText(String.valueOf(holder.bean.getVal2()));     holder.tvTotal.setText(String.valueOf(holder.bean.getTiempo())); }  public static class Holder {     Persona bean;     EditText etVal1;     EditText etVal2;     TextView tvTotal;     ImageButton ibDelete; }  private void setVal1TextChangeListener(final Holder holder) {     holder.etVal1.addTextChangedListener(new TextWatcher()     {          @Override         public void onTextChanged(CharSequence s, int start, int before, int count)         {             if(s.toString().length()>0)                 holder.bean.setNumero(Integer.parseInt(s.toString()));         }          @Override         public void beforeTextChanged(CharSequence s, int start, int count, int after) { }          @Override         public void afterTextChanged(Editable s) { }     }); } 

}

CLASE MAINACTIVITY protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);

    //Instantiating all member variables     names=new ArrayList<Persona>();     mContext = this;     mBtnStart = (Button) findViewById(R.id.btn_start);     mBtnLap = (Button) findViewById(R.id.btn_lap);     mBtnStop = (Button) findViewById(R.id.btn_stop);      mTvTimer = (TextView) findViewById(R.id.tv_timer);     //mEtLaps = (EditText) findViewById(R.id.et_laps);    // mEtLaps.setEnabled(false); //prevent the et_laps to be editable      //mSvLaps = (ScrollView) findViewById(R.id.sv_lap);     adapter = new ItemListAdapter(MainActivity.this, R.layout.item_list,names);     listView = (ListView)findViewById(R.id.listViewMain);     listView.setAdapter(adapter);      //btn_start click handler     mBtnStart.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {             //if the chronometer has not been instantiated before...             if(mChrono == null) {                 //instantiate the chronometer                 mChrono = new Chronometer(mContext);                 //run the chronometer on a separate thread                 mThreadChrono = new Thread(mChrono);                 mThreadChrono.start();                  //start the chronometer!                 mChrono.start();                  //clear the perilously populated et_laps                // mEtLaps.setText(""); //empty string!                  //reset the lap counter                 mLapCounter = 1;             }         }     });      //btn_stop click handler     mBtnStop.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {             //if the chronometer had been instantiated before...             if(mChrono != null) {                 //stop the chronometer                 mChrono.stop();                 //stop the thread                 mThreadChrono.interrupt();                 mThreadChrono = null;                 //kill the chrono class                 mChrono = null;             }          }     });      mBtnLap.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {              //if chrono is not running we shouldn't capture the lap!             if(mChrono == null) {                 Toast.makeText(mContext                         , R.string.warning_lap_button, Toast.LENGTH_SHORT).show();                 return; //do nothing!             }             Persona p=new Persona(0,mTvTimer.getText().toString());             names.add(p);             adapter.notifyDataSetChanged();               mSvLaps.post(new Runnable() {                 @Override                 public void run() {                     mSvLaps.smoothScrollTo(0, mEtLaps.getBottom());                 }             });*/          }     });   }  /**  * Update the text of tv_timer  * @param timeAsText the text to update tv_timer with  */ public void updateTimerText(final String timeAsText) {     runOnUiThread(new Runnable() {         @Override         public void run() {             mTvTimer.setText(timeAsText);         }     }); } public class Persona implements Serializable {   private int id;  private String nombre;  private String apellido; private String categoria; private int numero; 

CLASE PERSONA public Persona(String nombre, String apellido,String categoria, int numero) { this.nombre = nombre; this.numero=numero; this.apellido = apellido; this.categoria = categoria; }

public int getNumero() {     return numero; }  public void setNumero(int numero) {     this.numero = numero; }  public int getId() {     return id; }  public void setId(int id) {     this.id = id; }  public String getNombre() {     return nombre; }  public void setNombre(String nombre) {     this.nombre = nombre; }  public String getApellido() {     return apellido; }  public void setApellido(String apellido) {     this.apellido = apellido; }  public String getCategoria() {     return categoria; }  public void setCategoria(String categoria) {     this.categoria = categoria; } 

}

LAYOUT MAIN

<LinearLayout 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:focusable="true" android:focusableInTouchMode="true" android:orientation="vertical" tools:context="com.embedonix.chronometer.MainActivity">  <LinearLayout     android:layout_width="match_parent"     android:layout_height="wrap_content"      android:gravity="center"     android:orientation="vertical">       <TextView         android:id="@+id/tv_timer"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_gravity="center_horizontal"         android:ellipsize="end"         android:scrollbars="none"         android:text="00:00:00:000"         android:textAlignment="center"         android:textColor="#0dff00"         android:textSize="48dp"/>  </LinearLayout>  <LinearLayout     android:layout_weight="0.2"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical">         <ListView             android:id="@+id/listViewMain"             android:background="#ffffff"             android:layout_width="match_parent"             android:layout_height="wrap_content" >         </ListView> </LinearLayout>  <LinearLayout     android:layout_weight="0.9"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:background="#1f1d1d"     android:orientation="horizontal">      <Button         android:id="@+id/btn_start"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="1"         android:text="START"         android:textSize="18dp"         android:typeface="monospace"/>      <Button         android:id="@+id/btn_lap"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="1"         android:text="LAP"         android:textSize="18dp" />      <Button         android:id="@+id/btn_stop"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="1"         android:text="STOP"         android:textSize="18dp"/>     <Button         android:id="@+id/btn_terminar"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_weight="1"         android:text="FIN"         android:textSize="18dp"/> </LinearLayout> 

LAYOUT ITEM_LIST

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" >  <EditText     android:id="@+id/texto"     android:layout_width="0sp"     android:layout_height="fill_parent"     android:layout_weight="1"     android:text="Corredor Nª"     android:gravity="center_vertical"     android:textAppearance="?android:attr/textAppearanceSmall" />  <EditText     android:id="@+id/nrocompetidor"     android:layout_width="0sp"     android:layout_height="fill_parent"     android:layout_weight="1"     android:gravity="center"     android:inputType="numberDecimal"     android:textAppearance="?android:attr/textAppearanceSmall" />  <TextView     android:id="@+id/et_laps"     android:layout_width="0sp"     android:layout_height="fill_parent"     android:layout_weight="1"     android:gravity="center"     android:text="Total"     android:textAppearance="?android:attr/textAppearanceSmall" />