Question

我试图计算谷歌地图上两个位置之间的距离。我从EditText输入纬度和经度，但返回值为零米。代码出了什么问题，即如何获得真正的距离？

这是我的应用的图片：

enter image description here

public class Ma`inActivity extends AppCompatActivity implements OnMapReadyCallback {
private TextView source;
private TextView destination;
private EditText sLatitude1;
private EditText sLongtiude1;
private EditText dLatitude2;
private EditText dLongtiude2;
private Button button;

private GoogleMap mMap;
boolean mapReady = false;
MarkerOptions elsedaway;
MarkerOptions Elrob3;
Location location;



 static final CameraPosition elfayoum = CameraPosition.builder()
        .target(new LatLng(29.309324, 30.842973))
        .zoom(1)
        .bearing(6)
        .tilt(45)
        .build();
double lati1;
double longi1;
double lati2;
double longi2;
TextView textView;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // find text that display distance
    textView = (TextView) findViewById(R.id.distance);
    MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
    // find edit text and text view
    source = (TextView) findViewById(R.id.sourc);
    destination = (TextView) findViewById(R.id.destination);
    sLatitude1 = (EditText) findViewById(R.id.lat1);
    sLongtiude1 = (EditText) findViewById(R.id.long1);
    dLatitude2 = (EditText) findViewById(R.id.lat2);
    dLongtiude2 = (EditText) findViewById(R.id.long2);
    // find button
    button = (Button) findViewById(R.id.getDistance);
    // find string from edittext
    String lat1 = sLatitude1.getText().toString();
    // parse string to double
    lati1 = ParseDouble(lat1);
    String lon1 = sLongtiude1.getText().toString();
    longi1 = ParseDouble(lon1);
    String lat2 = dLatitude2.getText().toString();
    lati2 = ParseDouble(lat2);
    String lon2 = dLongtiude2.getText().toString();
    longi2 = ParseDouble(lon2);
    Log.i("**lat", lat2);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            double xy1 = distanceBetween(new LatLng(lati1, longi1), new LatLng(lati1, longi2));
            String distanceis = fmt(xy1) + "meter";
            textView.setText(distanceis);
        }

    });


}

// mehtod to parse double from string

double ParseDouble(String strNumber) {
    if (strNumber != null && strNumber.length() > 0) {
        try {
            return Double.parseDouble(strNumber);
        } catch (Exception e) {
            return -1;   // or some value to mark this field is wrong. or make a function validates field first ...
        }
    } else return 0;
}

// get distance
public static Double distanceBetween(LatLng point1, LatLng point2) {
    if (point1 == null || point2 == null) {
        return null;
    }
    double vw = SphericalUtil.computeDistanceBetween(point1, point2);
    Log.i("distance isby utillib ", String.valueOf(vw));
    return vw;
}

public String fmt(double d) {

    return String.format("%s", d);
}

@Override
public void onMapReady(GoogleMap googleMap) {
    mapReady = true;
    mMap = googleMap;
    //    if(elsedaway!=null){
    //    mMap.addMarker(elsedaway);};
   //      mMap.addMarker(Elrob3);

 mMap.addPolyline(new PolylineOptions().geodesic(true)
                    .add(new LatLng(lati1, longi1))
                    .add(new LatLng(lati2, lati2))
            mMap.addCircle(new CircleOptions()
                    .center(new LatLng(29.291540, 30.601884))
                    .radius(500044)
                    .strokeColor(Color.GREEN)
                    .fillColor(Color.argb(54, 99, 255, 0)));
    flyTo(elfayoum);
}

Answer 1

这link可能会帮助您找到2个长点之间的距离。

Here是hasrsine公式的java实现。

希望这可能会有所帮助

Answer 2

将这段代码移动到onCLick中，并更正您的值，您的代码应如下：

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="body">
  <div ng-controller="FrameController as vm">
    
<div id="myContainer">

  <table id="table1">
      <tbody>
      <tr>
          <td class="column1" style="width: 80px">Red Apple</td>
          <td class="column2"> Lorem ipsum dolor sit amet </td>
          <td class="column3">U$ 0.12</td>
      </tr>
          <tr>
          <td class="column1">Red Apple</td>
          <td class="column2"> Lorem ipsum dolor sit amet, </td>
          <td class="column3">U$ 0.12</td>
      </tr>
      </tbody>
  </table>
  
  <table id="table2">
      <tbody>
      <tr>
          <td class="column1">Red Apple</td>
          <td class="column2"></td>
          <td class="column3">U$ 0.12</td>
      </tr>
          <tr>
          <td class="column1">Red Apple</td>
          <td class="column2"></td>
          <td class="column3">U$ 0.12</td>
      </tr>
      </tbody>
  </table>
  
    <table id="table3">
      <tbody>
      <tr>
          <td class="column1">Red Apple</td>
          <td class="column2"> Lorem ipsum dolor sit amet </td>
          <td class="column3">U$ 0.12</td>
      </tr>
          <tr>
          <td class="column1">Red Apple</td>
          <td class="column2"> Lorem ipsum dolor sit amet, </td>
          <td class="column3">U$ 0.12</td>
      </tr>
      </tbody>
  </table>

</div>
<button ng-click="vm.pressTab()"> Press Tab</button>
  </div>
</div>

Answer 3

首先，这里有一个错误：

double xy1 = distanceBetween(new LatLng(lati1, longi1), new LatLng(lati1, longi2));

您应该在第二个参数中使用lati2而不是lati1。

另外，将getText()移到onClick(...)区块内。

    button.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v)
          {
              // find string from edittext
              String lat1 = sLatitude1.getText().toString();
              // parse string to double
              lati1 = ParseDouble(lat1);
              String lon1 = sLongtiude1.getText().toString();
              longi1 = ParseDouble(lon1);
              String lat2 = dLatitude2.getText().toString();
              lati2 = ParseDouble(lat2);
              String lon2 = dLongtiude2.getText().toString();
              longi2 = ParseDouble(lon2);

              ...
          }
      });

通过从EditText输入纬度和经度来计算两个位置之间的距离

3 个答案: