problem with graphics layer when running activities as apllication.

[devendraverma]

Hi Guys
I am new to android development.
I made 5 activities with geo processing in them.
when running individualy its fine.
but when i used one activity as menu for all 5 GP Activities and navigating to them via intents, for the very first time the graphics layer is visible but for putting a point, but as soon as i press back button and again navigate to any of the Activities, on compilation side every thing is going fine, no exceptions but  no graphics are visible on graphics layer....

I am pasting code for one GP activity....
please help me i dont kno what i am doing wrong...


package com.esri.android.sample;

import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;

import com.esri.android.map.GraphicsLayer;
import com.esri.android.map.MapView;
import com.esri.android.map.ags.ArcGISTiledMapServiceLayer;
import com.esri.android.map.event.OnSingleTapListener;
import com.esri.core.geometry.Geometry;
import com.esri.core.geometry.Point;
import com.esri.core.map.Graphic;
import com.esri.core.symbol.SimpleFillSymbol;
import com.esri.core.symbol.SimpleMarkerSymbol;
import com.esri.core.symbol.SimpleMarkerSymbol.STYLE;
import com.esri.core.tasks.ags.geoprocessing.GPFeatureRecordSetLayer;
import com.esri.core.tasks.ags.geoprocessing.GPParameter;
import com.esri.core.tasks.ags.geoprocessing.GPResultResource;
import com.esri.core.tasks.ags.geoprocessing.GPString;
import com.esri.core.tasks.ags.geoprocessing.Geoprocessor;

import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Handler.Callback;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.Toast;

public class DriveTimes extends Activity{

protected static final int CLOSE_LOADING_WINDOW = 0;
protected static final int CANCEL_LOADING_WINDOW = 1;
private MapView map = null;
private ArrayList<GPParameter> params;
private Geoprocessor gp;
private GraphicsLayer gLayer;
private ProgressDialog dialog = null;
private Timer cancelDriveTimes = new Timer();
private ImageButton delete, go;
private Point mappoint;


private Handler uiHandler = new Handler(new Callback() {
  public boolean handleMessage(Message msg) {
   switch (msg.what) {
   case CLOSE_LOADING_WINDOW:
    if (dialog != null) {
     dialog.dismiss();
    }
    cancelDriveTimes.cancel();
    break;
   case CANCEL_LOADING_WINDOW:
    if (dialog != null) {
     dialog.dismiss();
    }
    Toast toast = Toast.makeText(DriveTimes.this,
      "Taking too long to execute, canceled", Toast.LENGTH_SHORT);
    toast.show();
    break;
   }
   return false;
  }

});

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.drive_times);
 
  map = (MapView)findViewById(R.id.map);
  // Add dynamic layer to MapView
  map.addLayer(new ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer")); 
 
 
  gLayer = new GraphicsLayer();
  map.addLayer(gLayer);
 
  delete = (ImageButton)findViewById(R.id.deletebutton);
  go = (ImageButton)findViewById(R.id.gobutton);
 
  Toast.makeText(this, "Single tap on the map", Toast.LENGTH_SHORT).show();

  /**
   * Clear all graphics from the graphics layer. The method is called when
   * the trash can button is clicked by the user.
   */
  delete.setOnClickListener(new OnClickListener() {
  
   public void onClick(View v) {
    gLayer.removeAll();
   
   }
  });
  delete.setOnClickListener(new OnClickListener() {
   public void onClick(View arg0) {
    gLayer.removeAll();
   }
  });
 
  /**
   * In response to the clicking of the arrow button
   */
 
  go.setOnClickListener(new OnClickListener() {
  
   public void onClick(View v) {
    start(mappoint);
   
   }
  });
  go.setOnClickListener(new OnClickListener() {
   public void onClick(View arg0) {
    start(mappoint);
   }
  });

  map.setOnSingleTapListener(new OnSingleTapListener() {
   private static final long serialVersionUID = 1L;

   public void onSingleTap(float x, float y) {
    mappoint = map.toMapPoint(x, y);
    Graphic g = new Graphic(mappoint,new SimpleMarkerSymbol(Color.RED, 10, STYLE.CIRCLE));
    gLayer.addGraphic(g);
   }
  });
 
  //Retrieve the non-configuration instance data that was previously returned.
  Object init = getLastNonConfigurationInstance();
  if (init != null) {
   map.restoreState((String) init);
  } 
 
}

class DriveTimesQuery extends AsyncTask<ArrayList<GPParameter>, Void, GPParameter[]> {

  GPParameter[] outParams = null;

  @Override
  protected void onPostExecute(GPParameter[] result) {
   if (outParams == null)
    return;
   for (int i = 0; i < outParams.length; i++) {
    if (outParams instanceof GPFeatureRecordSetLayer) {

     GPFeatureRecordSetLayer fsl = (GPFeatureRecordSetLayer) outParams;
     SimpleFillSymbol buffer1=new SimpleFillSymbol(Color.GRAY);
     SimpleFillSymbol buffer2=new SimpleFillSymbol(Color.BLUE);
     SimpleFillSymbol buffer3=new SimpleFillSymbol(Color.RED);
     buffer1.setAlpha(5);
     buffer2.setAlpha(5);
     buffer3.setAlpha(5);
     int count=0;
     for (Graphic feature : fsl.getGraphics()) {
      if(count==0)
      {
       Graphic g = new Graphic(feature.getGeometry(),buffer1);
       gLayer.addGraphic(g);
      
      }
      else if(count==1)
      {
       Graphic g1 = new Graphic(feature.getGeometry(),buffer2);
          gLayer.addGraphic(g1);
         
         }
      else if(count==2)
      {
       Graphic g2 = new Graphic(feature.getGeometry(),buffer3);
          gLayer.addGraphic(g2);
         
      }
     
      count=count + 1;
     }
    }
   }
   uiHandler.sendEmptyMessage(CLOSE_LOADING_WINDOW);
  }

  @Override
  protected GPParameter[] doInBackground(ArrayList<GPParameter>... params1) {

   gp = new Geoprocessor("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Network/ESRI_DriveTime_US/GPServer/Create...");
   gp.setOutSR(map.getSpatialReference().getID());
   try {
    GPResultResource rr = gp.execute(params1[0]);
    outParams = rr.getOutputParameters();
   } catch (Exception e) {
    e.printStackTrace();
   }
   return outParams;
  }
}

/**
  * 1) Create the GP object by passing it the url. 2) Create the input
  * parameters and add to the GPParameter object. 3) Pass these params to the
  * execute method.
  *
  * @param mappoint
  *            - point selected on the map by the user
  */
public void start(Point mappoint) {
  // First input parameter
  GPFeatureRecordSetLayer gpf = new GPFeatureRecordSetLayer("Input_Location");
  gpf.setSpatialReference(map.getSpatialReference());
  gpf.setGeometryType(Geometry.Type.Point);
  // Add the point selected by the user
  Graphic f = new Graphic(mappoint,new SimpleMarkerSymbol(Color.RED,25,STYLE.DIAMOND));
  gpf.addGraphic(f);

  // Second input parameter
  GPString gps=new GPString("Drive_Times");
  gps.setValue("2 5 7");
  //GPLinearUnit gpl = new GPLinearUnit("Days");
  //gpl.setUnits("esriDouble");
  //gpl.setDistance(365);

  // Add params
  params = new ArrayList<GPParameter>();
  params.add(gpf);
  params.add(gps);

  try {
   dialog = ProgressDialog.show(DriveTimes.this, "", "Loading. Please wait...", true, true);
   new DriveTimesQuery().execute(params);
   cancelDriveTimes = new Timer();
   cancelDriveTimes.schedule(new TimerTask() {

    @Override
    public void run() {
     uiHandler.sendEmptyMessage(CANCEL_LOADING_WINDOW);
    }
   }, 60000);
  } catch (Exception e) {
   e.printStackTrace();
  }
}

@Override
protected void onPause() {
  super.onPause();
  map.pause();
}

@Override 
protected void onResume() {
  super.onResume();
  map.unpause();
}

@Override
public void onBackPressed() {
  // TODO Auto-generated method stub
  this.finish();
  super.onBackPressed();
}


}

[ManuelImedio]

Do not know if it will but try, put onBackPressed method,

public void onBackPressed() {
// TODO Auto-generated method stub
if (map.isLoaded()) {
  this.finish();
super.onBackPressed();
}
}

[GwenRoyakkers1]

I've had the same problem.
You are not doing anything wrong.
It was a bug in the sdk.

I solved this by forcing the activity proces to close in onDestroy().
When you start a fresh activity this problem doesn't happen.

However this problem is solved in the newer api releases (v1.1 and V1.1.1).
There are some other lifecycle issues, but these may not be problematic in your application.

So I suggest updating to V1.1.1


Regards

Gwen.