当我运行此代码时，它显示错误。拜托，帮帮我吧。我正试图在Android操作系统的Google地图中找到从一个地方到另一个地方的路线。
我已经提交了所有代码。我想我不需要提交我的xml布局代码。让我们说，它只是地图视图。
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.screenfive);
coder = new Geocoder(this);
EditText startedit =(EditText) findViewById(R.id.startedit);
EditText finishedit =(EditText) findViewById(R.id.finishedit);
Button go=(Button) findViewById(R.id.go);
Spinner spinnercategory = (Spinner) findViewById (R.id.spinnercategory);
Category =(TextView) findViewById(R.id.category);
mapView = (MapView) findViewById(R.id.mymapview2);
mapView.setBuiltInZoomControls(true);
mMapController = mapView.getController();
// mMapController.setZoom(18);
// Two points in Mexico about 1km apart
//Take any two points
GeoPoint point1 = new GeoPoint(19240000,-99120000);
GeoPoint point2 = new GeoPoint(19241000,-99121000);
mMapController.setCenter(point2);
// Pass the geopoints to the overlay class
mapOvlay = new MapOverlay(point1, point2);
mapView.getOverlays().add(mapOvlay);
spinnercategory.setOnItemSelectedListener(this);
ArrayAdapter aa=new ArrayAdapter(this, android.R.layout.simple_spinner_item,category);
aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnercategory.setAdapter(aa);
go.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
new GetLatLong().execute();
}
});
}
public void onItemSelected(AdapterView<?> parent, View v, int position,
long id) {
// Category.setText(category[position]);
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
public class MapOverlay extends com.google.android.maps.Overlay {
private GeoPoint mGpt1;
private GeoPoint mGpt2;
protected MapOverlay(GeoPoint gp1, GeoPoint gp2 ) {
mGpt1 = gp1;
mGpt2 = gp2;
}
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
long when) {
super.draw(canvas, mapView, shadow);
Paint paint;
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setAntiAlias(true);
paint.setStyle(Style.STROKE);
paint.setStrokeWidth(2);
Point pt1 = new Point();
Point pt2 = new Point();
Projection projection = mapView.getProjection();
projection.toPixels(mGpt1, pt1);
projection.toPixels(mGpt2, pt2);
canvas.drawLine(pt1.x, pt1.y, pt2.x, pt2.y, paint);
return true;
}
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
}
class GetLatLong extends AsyncTask<String, Void, String>
{
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
ProgressDialog=new ProgressDialog(MapActivityForScreen5.this);
ProgressDialog.setTitle("Loading");
ProgressDialog.show();
}
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
try{
addressgone = coder.getFromLocationName(startedit.getText().toString(),5);
if (addressgone == null) {
}
Address locationgone = addressgone.get(0);
locationgone.getLatitude();
locationgone.getLongitude();
pone = new GeoPoint((int) (locationgone.getLatitude() * 1E6),
(int) (locationgone.getLongitude() * 1E6));
}
catch(Exception e)
{
}
try{
addressgtwo = coder.getFromLocationName(startedit.getText().toString(),5);
if (addressgtwo == null) {
}
Address locationgtwo = addressgtwo.get(0);
locationgtwo.getLatitude();
locationgtwo.getLongitude();
ptwo = new GeoPoint((int) (locationgtwo.getLatitude() * 1E6),
(int) (locationgtwo.getLongitude() * 1E6));
}
catch(Exception e)
{
}
return null;
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
ProgressDialog.cancel();
mMapController.setCenter(ptwo);
// Pass the geopoints to the overlay class
mapOvlay = new MapOverlay(pone, ptwo);
mapView.getOverlays().add(mapOvlay);
}
}
}
答案 0 :(得分：1)
从工作线程访问UI组件是一种糟糕的编程习惯。 AsyncTask工作线程独立于UI线程运行，它们可能无法访问textView，因此startedit.getText().toString()返回null。
好的风格是你用execute()方法传递这些值，所以试试
`new GetLatLong().execute(startedit.getText().toString());`
并在doInBackground(String... params)中，正确的实施将是
String value=params[0];
try{
addressgone = coder.getFromLocationName(value,5);
if (addressgone == null) {
}`...
答案 1 :(得分：0)
最后我做了。我发布了这个答案，以便它对你有用。 我是通过使用JSON（在EditText中获取纬度和经度）并使用Google地图服务在两个地方之间绘制路线来完成的。
以下是代码：
JSONObject jsonObjectto = getLocationInfo(ToEditTextt.getText().toString());
JSONObject jsonObjectfrom = getLocationInfo(FromEditTextt.getText().toString());
Log.v("P1 Value",jsonObjectto+"");
getLatLongto(jsonObjectto);
getLatLongfrom(jsonObjectfrom);
try{
gp1 = new GeoPoint((int) (latittudefrom * 1E6),
(int) (longittutefrom * 1E6));
gp2 = new GeoPoint((int) (latittudeto * 1E6),
(int) (longittuteto * 1E6));
Log.v("To Value",gp2+"");
Log.v("From Value",gp1+"");
try{
mode=Modes.drivingmode;
if(routeoverlayy!=null){
mapView.getOverlays().remove(routeoverlayy);
}
if(gp1!=null && gp2!=null){
Route route = directions(gp1, gp2,mode);
routeoverlayy = new RouteOverlay(route, Color.BLUE);
mapView.postInvalidate();
// routeOverlay.redrawPath(mMapView);
mapView.postInvalidate();
mapcontrol.setCenter(gp1);
mapcontrol.setZoom(10);
mapcontrol.animateTo(gp1);
mapView.getOverlays().add(routeoverlayy);
pw.dismiss();
}
}
catch(Exception e){
}
}
catch(Exception e)
{
}
// search pressed and perform your functionality.
return true;
}
/*InputMethodManager
imm=(InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(.getWindowToken(), 0); */
return false;
}
});
}
public static JSONObject getLocationInfo(String address) {
StringBuilder stringBuilder = new StringBuilder();
try {
address = address.replaceAll(" ","%20");
HttpPost httppost = new HttpPost("http://maps.google.com/maps/api/geocode/json?address=" + address + "&sensor=false");
HttpClient client = new DefaultHttpClient();
HttpResponse response;
stringBuilder = new StringBuilder();
response = client.execute(httppost);
HttpEntity entity = response.getEntity();
InputStream stream = entity.getContent();
int b;
while ((b = stream.read()) != -1) {
stringBuilder.append((char) b);
}
} catch (ClientProtocolException e) {
} catch (IOException e) {
}
JSONObject jsonObject = new JSONObject();
try {
jsonObject = new JSONObject(stringBuilder.toString());
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return jsonObject;
}
public static boolean getLatLongto(JSONObject jsonObject) {
try {
longittuteto = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
.getJSONObject("geometry").getJSONObject("location")
.getDouble("lng");
Log.v("Longitude", longittuteto+"");
latittudeto = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
.getJSONObject("geometry").getJSONObject("location")
.getDouble("lat");
Log.v("Latitude", latittudeto+"");
} catch (JSONException e) {
return false;
}
return true;
}
public static boolean getLatLongfrom(JSONObject jsonObject) {
try {
longittutefrom = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
.getJSONObject("geometry").getJSONObject("location")
.getDouble("lng");
Log.v("Longitude", longittutefrom+"");
latittudefrom = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
.getJSONObject("geometry").getJSONObject("location")
.getDouble("lat");
Log.v("Latitude", latittudefrom+"");
} catch (JSONException e) {
return false;
}
return true;
}
public class RouteOverlay extends Overlay{
/** GeoPoints representing this routePoints. **/
private final List<GeoPoint> routePoints;
/** Colour to paint routePoints. **/
private int colour;
/** Alpha setting for route overlay. **/
private static final int ALPHA = 120;
/** Stroke width. **/
private static final float STROKE = 4.5f;
/** Route path. **/
private final Path path;
/** Point to draw with. **/
private final Point p;
/** Paint for path. **/
private final Paint paint;
/**
* Public constructor.
*
* @param route Route object representing the route.
* @param defaultColour default colour to draw route in.
*/
public RouteOverlay(final Route route, final int defaultColour) {
super();
routePoints = route.getPoints();
colour = defaultColour;
path = new Path();
p = new Point();
paint = new Paint();
}
@Override
public final void draw(final Canvas c, final MapView mv,
final boolean shadow) {
super.draw(c, mv, shadow);
paint.setColor(colour);
paint.setAlpha(ALPHA);
paint.setAntiAlias(true);
paint.setStrokeWidth(STROKE);
paint.setStyle(Paint.Style.STROKE);
redrawPath(mv);
c.drawPath(path, paint);
}
/**
* Set the colour to draw this route's overlay with.
*
* @param c Int representing colour.
*/
public final void setColour(final int c) {
colour = c;
}
/**
* Clear the route overlay.
*/
public final void clear() {
routePoints.clear();
}
/**
* Recalculate the path accounting for changes to
* the projection and routePoints.
* @param mv MapView the path is drawn to.
*/
private void redrawPath(final MapView mv) {
final Projection prj = mv.getProjection();
path.rewind();
final Iterator<GeoPoint> it = routePoints.iterator();
prj.toPixels(it.next(), p);
path.moveTo(p.x, p.y);
while (it.hasNext()) {
prj.toPixels(it.next(), p);
path.lineTo(p.x, p.y);
}
path.setLastPoint(p.x, p.y);
}
}
private Route directions(final GeoPoint start, final GeoPoint dest,int mode) {
Parser parser;
String jsonURL = "http://maps.googleapis.com/maps/api/directions/json?";
final StringBuffer sBuf = new StringBuffer(jsonURL);
sBuf.append("origin=");
sBuf.append(start.getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(start.getLongitudeE6()/1E6);
sBuf.append("&destination=");
sBuf.append(dest.getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(dest.getLongitudeE6()/1E6);
if(mode==1){
sBuf.append("&sensor=true&mode=driving");
}
if(mode==3){
System.currentTimeMillis();
try{
sBuf.append("&sensor=true&departure_time=1343605500&mode=google.maps.TravelMode.TRANSIT&vehicle.type=VehicleType.BUS");
}catch(Exception e){
Toast.makeText(ScreenOfOnMyWay.this, "Route not available", Toast.LENGTH_SHORT).show();
}
}
if(mode==2){
sBuf.append("&sensor=true&mode=walking");
}
parser = new GoogleParser(sBuf.toString());
Route r = parser.parse();
return r;
}