Question

我已经写了代码，用于在地图上显示各种人的位置。我正在从PHP脚本解析Json数据。我想在地图上显示带有文字的图标。我的图标显示完美，但它没有显示相关的文本。我的代码如下。如何在地图上显示带有INFO的图标？

public class Maps extends MapActivity {

    private void callPolice()
    {
            Intent callintent = new Intent(Intent.ACTION_CALL);
            callintent.setData(Uri.parse("tel:6100"));
            startActivity(callintent);
    }


private MapView mapView;

JSONArray jArray;
String result = null;
InputStream is = null;
StringBuilder sb=null;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);

//button code starts here
Button panic_button = (Button) findViewById(R.id.button1);

panic_button.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://xyz.com/index.php");

        try {
            // Add your data
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
           nameValuePairs.add(new BasicNameValuePair("uid", "4"));
           httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            // Execute HTTP Post Request
           //Toast.makeText(this, resId, duration)
            HttpResponse response = httpclient.execute(httppost);

        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
        callPolice();

    }
});
//button code ends
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy); 

mapView = (MapView) findViewById(R.id.themap);       
        mapView.setBuiltInZoomControls(true);
      mapView.setSatellite(true);
      mapView.invalidate();

 ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
//http post
try{
     HttpClient httpclient = new DefaultHttpClient();
     HttpPost httppost = new HttpPost("http://xyz/maps.php");
     httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
     HttpResponse response = httpclient.execute(httppost);
     HttpEntity entity = response.getEntity();
     is = entity.getContent();
     }catch(Exception e){
         Log.e("log_tag", "Error in http connection"+e.toString());
    }
//convert response to string
try{
      BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
       sb = new StringBuilder();
       sb.append(reader.readLine() + "\n");

       String line="0";
       while ((line = reader.readLine()) != null) {
                      sb.append(line + "\n");
        }
        is.close();
        result=sb.toString();
        }catch(Exception e){
              Log.e("log_tag", "Error converting result "+e.toString());
        }
//paring data
double LAT;
double LANG;
String INFO;
try{
      jArray = new JSONArray(result);
      JSONObject json_data=null;
      for(int i=0;i<jArray.length();i++){
             json_data = jArray.getJSONObject(i);
             LAT=json_data.getDouble("lat");
             LANG=json_data.getDouble("lon");
             INFO=json_data.getString("name");


//Overlay code
List<Overlay> mapOverlays = mapView.getOverlays();
                Drawable drawable = this.getResources().getDrawable(R.drawable.mark_red);
       // CustomItemizedOverlay itemizedOverlay = new CustomItemizedOverlay(drawable, this);
                AddItemizedOverlay itemizedOverlay = new AddItemizedOverlay(drawable, this);
        //GeoPoint point = new GeoPoint(latitudeE6, longitudeE6);
        GeoPoint point = new GeoPoint((int)(LAT * 1e6),(int)(LANG * 1e6));
        OverlayItem overlayitem = new OverlayItem(point, INFO, INFO);
        itemizedOverlay.addOverlay(overlayitem);
        mapOverlays.add(itemizedOverlay);

        MapController mapController = mapView.getController();

        mapController.animateTo(point);
        mapController.setZoom(15);


//Overlay code

         }
      }
      catch(JSONException e1){
          Toast.makeText(getBaseContext(), "No City Found" ,Toast.LENGTH_LONG).show();
      } catch (ParseException e1) {
            e1.printStackTrace();
    }
}
@Override
protected boolean isRouteDisplayed() {
    return false;
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_maps, menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{

    switch (item.getItemId())
    {
    case R.id.menu_friends:
        Intent intent = new Intent(this, Friends.class);
        startActivity(intent);
        return true;

    case R.id.menu_invite:
        Intent intent1 = new Intent(this, Invite.class);
        startActivity(intent1);
        return true;

    case R.id.menu_logout:
        Intent intent2 = new Intent(this, Logout.class);
        startActivity(intent2);
        return true;


    default:
        return super.onOptionsItemSelected(item);
    }
} 
}

Answer 1

修改AddItemizedOverlay以包含onDraw方法覆盖，并修改构造函数以包含textsize参数：

public class MapItemizedOverlay extends ItemizedOverlay<OverlayItem>
{
//member variables
private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
private Context mContext;
private int mTextSize;


public MapItemizedOverlay(Drawable defaultMarker, Context context, int textSize)
{
    super(boundCenterBottom(defaultMarker));
    mContext = context;
    mTextSize = textSize;
}


//In order for the populate() method to read each OverlayItem, it will make a request to createItem(int)
// define this method to properly read from our ArrayList
@Override
protected OverlayItem createItem(int i)
{
    return mOverlays.get(i);
}


@Override
public int size()
{
    return mOverlays.size();
}

@Override
protected boolean onTap(int index)
{
    OverlayItem item = mOverlays.get(index);

    //Do stuff here when you tap, i.e. :
    AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
    dialog.setTitle(item.getTitle());
    dialog.setMessage(item.getSnippet());
    dialog.show();

    //return true to indicate we've taken care of it
    return true;
}

@Override
public void draw(android.graphics.Canvas canvas, MapView mapView, boolean shadow)
{
    super.draw(canvas, mapView, shadow);

    if (shadow == false)
    {
        //cycle through all overlays
        for (int index = 0; index < mOverlays.size(); index++)
        {
            OverlayItem item = mOverlays.get(index);

            // Converts lat/lng-Point to coordinates on the screen
            GeoPoint point = item.getPoint();
            Point ptScreenCoord = new Point() ;
            mapView.getProjection().toPixels(point, ptScreenCoord);

            //Paint
            Paint paint = new Paint();
            paint.setTextAlign(Paint.Align.CENTER);
            paint.setTextSize(mTextSize);
            paint.setARGB(150, 0, 0, 0); // alpha, r, g, b (Black, semi see-through)

            //show text to the right of the icon
            canvas.drawText(item.getTitle(), ptScreenCoord.x, ptScreenCoord.y+mTextSize, paint);
        }
    }
}


public void addOverlay(OverlayItem overlay)
{
    mOverlays.add(overlay);
    populate();
}


public void removeOverlay(OverlayItem overlay)
{
    mOverlays.remove(overlay);
    populate();
}


public void clear()
{
    mOverlays.clear();
    populate();
}

}

android地图叠加不显示文字

1 个答案: