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Android TextView setText overlays previous Text

问题描述:

I would like to set a Text into a TextView of my app(lication). This is the code I used:

TextView lonTextView = (TextView) findViewById(R.id.textViewLonWert);

lonTextView.setText(longitude.toString());

Actually it works, but the previous Text is still displayed! For example a 4 overlays an 8 (you cannot read the text any more).

I have a Activity starting a service. Then registering a LocalBroadcastReceiver to the Activity. The service peridically sends location objects to the activity. From the location I get e.g. the longitude and would like to update a textview (just contains the longitude) with the new longitude.

I would be very pleased if anyone has an idea to solve this problem.

UPDATE:

The full code is quite long, so here are the relevant fragments:

TrackingActivity.java

public class TrackingActivity extends Activity {

// GPSTracker class

GPSTracker gps;

public String filename;

/* Um eigene Position anzuzeigen */

ArrayList<OverlayItem> overlayItemArray;

protected MapView mapView;

protected MapController mapController;

public Boolean isPause;

public Boolean isTracking;

public MyLocationOverlay myLocationOverlay;

PathOverlay myPath;

List<GeoPoint> path;

public BroadcastReceiver screenReceiver;

/* Textviews setzen */

TextView lonTextView;

TextView latTextView;

TextView altTextView;

TextView accTextView;

// Initiating Menu XML file (menu.xml)

/*@Override

public boolean onCreateOptionsMenu(Menu menu)

{

MenuInflater menuInflater = getMenuInflater();

menuInflater.inflate(R.menu.menu_tracking, menu);

MenuItem mi_startTracking = menu.findItem(R.id.start_tracking);

mi_startTracking.setVisible(true);

return true;

}*/

/**

* Event Handling for Individual menu item selected

* Identify single menu item by it's id

* */

@Override

public boolean onOptionsItemSelected(MenuItem item)

{

...

}

@Override

public boolean onPrepareOptionsMenu(Menu menu) {

...

}

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_tracking);

isTracking = false;

isPause = false;

// create GPS-class object

gps = new GPSTracker(TrackingActivity.this

,null);

myPath = new PathOverlay(Color.RED, this);

path = new ArrayList<GeoPoint>();

/* Map anzeigen */

mapView = new MapView(this, 500);

mapView.setTileSource(TileSourceFactory.MAPNIK);

org.osmdroid.views.MapView.LayoutParams mapParams = new org.osmdroid.views.MapView.LayoutParams(

org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,

org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,

null, 0, 0, 0);

/*löst Fehler aus: mapView.setClickable(true);*/

mapView.setBuiltInZoomControls(true);

mapController = new MapController(mapView);

mapView.getController().setZoom(15);

//--- Create Overlay

overlayItemArray = new ArrayList<OverlayItem>();

DefaultResourceProxyImpl defaultResourceProxyImpl = new DefaultResourceProxyImpl(this);

MyItemizedIconOverlay myItemizedIconOverlay = new MyItemizedIconOverlay(

overlayItemArray, null, defaultResourceProxyImpl);

mapView.getOverlays().add(myItemizedIconOverlay);

//---

//Add current position

myLocationOverlay = new MyLocationOverlay(this, mapView);

mapView.getOverlays().add(myLocationOverlay);

/* Lege Pfad auf Karte */

mapView.getOverlays().add(myPath);

mapView.invalidate();

LinearLayout myLayout = (LinearLayout) findViewById(R.id.trackingLinearLayoutMap);

myLayout.addView(mapView,mapParams);

}

private BroadcastReceiver gpsDataReceiver = new BroadcastReceiver() {

@Override

public void onReceive(Context context, Intent intent) {

//Log.d("TrackingActivity", "in Receiver");

/* alles was der Service liefert */

String action = intent.getAction();

Double altitude = intent.getDoubleExtra("altitude", 0);

Double longitude = intent.getDoubleExtra("longitude", 0);

Double latitude = intent.getDoubleExtra("latitude", 0);

Bundle b = intent.getExtras();

Location location = (Location)b.get("location");

Log.d("received","Receiver: "+longitude+" ; "+latitude);

//Log.d("TrackingActivity", "vor GeoPoint");

GeoPoint locGeoPoint = new GeoPoint(latitude, longitude);

/* Erstelle Pfad */

if(isTracking){

path.add(locGeoPoint);

myPath.addPoint(locGeoPoint);

}

//Log.d("TrackingActivity", "nach GeoPoint: "+locGeoPoint.toString());

mapController.setCenter(locGeoPoint);

setOverlayLoc(location);

/* Textviews Werte setzen */

lonTextView = (TextView) findViewById(R.id.textViewLonWert);

lonTextView.setText(longitude.toString());

//lonTextView.invalidate();

latTextView = (TextView) findViewById(R.id.textViewLatWert);

latTextView.setText(latitude.toString());

//latTextView.invalidate();

altTextView = (TextView) findViewById(R.id.textViewAltWert);

altTextView.setText(altitude.toString());

//altTextView.invalidate();

accTextView = (TextView) findViewById(R.id.textViewAccWert);

accTextView.setText(Float.toString(location.getAccuracy())+" m");

//accTextView.invalidate();

/* Karte aktualisieren */

mapView.invalidate();

}

};

...

@Override

protected void onResume() {

super.onResume();

/* Registriere BroadcastReceiver für GPSDaten */

LocalBroadcastManager.getInstance(this).registerReceiver(gpsDataReceiver, new IntentFilter("gpsdata"));

...

}

...

Here my layout .xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/trackingLinearLayout"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

<LinearLayout

android:id="@+id/trackingStatusOuterWrapper"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical" >

<TextView

android:id="@+id/textView1"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="kein GPS Signal"

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<LinearLayout

android:id="@+id/trackingStautsInnerWrapper2"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal" >

<TextView

android:id="@+id/textViewLonLabel"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Länge: "

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewLonWert"

android:layout_width="80dp"

android:layout_height="wrap_content"

android:text=""

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewLatLabel"

android:layout_marginLeft="40dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Breite: "

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewLatWert"

android:layout_width="80dp"

android:layout_height="wrap_content"

android:text=""

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

</LinearLayout>

<LinearLayout

android:id="@+id/trackingStautsInnerWrapper3"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal" >

<TextView

android:id="@+id/textViewAltLabel"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Höhe: "

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewAltWert"

android:layout_width="80dp"

android:layout_height="wrap_content"

android:text=""

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewAccLabel"

android:layout_marginLeft="40dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Genauigkeit: "

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

<TextView

android:id="@+id/textViewAccWert"

android:layout_width="80dp"

android:layout_height="wrap_content"

android:text=""

android:textAppearance="?android:attr/textAppearanceSmall"

android:textSize="10sp" />

</LinearLayout>

</LinearLayout>

<!--

<org.osmdroid.views.MapView

xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/mapview"

android:layout_width="fill_parent"

android:layout_height="match_parent"

android:clickable="true"/>

-->

<LinearLayout

android:id="@+id/trackingLinearLayoutMap"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical" >

</LinearLayout>

Hope it helps!

网友答案:

You'll never believe this, but if you head over to How often can you update a textview without mess you will find a question and answer which I think are addressing the issue.

If these don't resolve the issue, you may need to replace the button with a custom View with the onDraw overridden using canvas.drawText() to put the text in place. You can then be sure to wipe any previous history ...

IF you just want a non transparent black background, create (or add to) the colors.xml file in your res directory:

<resources>
    <color name="black">#ff000000</color>
</resources>

and add:

    android:background="@color/black"

To the xml for the TextView.

网友答案:

The line android:text="" in

    <TextView
    android:id="@+id/textViewLonWert"
    android:layout_width="80dp"
    android:layout_height="wrap_content"
    android:text=""
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textSize="10sp" />

is redundant, you can remove that line.

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