Question

当我打开我的应用程序并且它没有添加标记时，Camera Animation无法指向我的位置

 public class MapsActivity extends FragmentActivity {

private GoogleMap mMap; // Might be null if Google Play services APK is not available.



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

}


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

这里它不会将我的相机指向我当前的位置。当我打开我的应用程序时，它从地图的中心开始而不是我的位置

private void setUpMapIfNeeded() {
    // Do a null check to confirm that we have not already instantiated the map.
    if (mMap == null) {
        // Try to obtain the map from the SupportMapFragment.
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                .getMap();
        mMap.setMyLocationEnabled(true);
        // Check if we were successful in obtaining the map.
        if (mMap != null) {
            setUpMapIfNeeded();

        }
    }

}

private void setUpMap() {
    mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker").snippet("Snippet"));
    mMap.setMyLocationEnabled(true);
    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    String provider = locationManager.getBestProvider(criteria, true);
    Location location = locationManager.getLastKnownLocation(provider);

    if (location != null) {

        LatLng target = new LatLng(location.getLatitude(), location.getLongitude());
        CameraPosition position = this.mMap.getCameraPosition();

        CameraPosition.Builder builder = new CameraPosition.Builder();
        builder.zoom(15);
        builder.target(target);

        this.mMap.animateCamera(CameraUpdateFactory.newCameraPosition(builder.build()));
        mMap.addMarker(new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("You are here!").snippet("Consider yourself located"));
    }
}
}

Answer 1

你有几个巨大的超级基本错误：

只有当baground中的活动到达前台时才会调用onResume。将setUpMapIfNeeded()放在onCreate内。

在上一个setUpMapIfNeeded()语句中，您的函数if中的第二个而不是setUpMap()您将setUpMapIfNeeded()更改为public class MapsActivity extends FragmentActivity { private GoogleMap mMap; // Might be null if Google Play services APK is not available.，它应该有效。

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

}


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

以下是您修改的代码：

第1部分

private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
    // Try to obtain the map from the SupportMapFragment.
    mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
            .getMap();
   mMap.setMyLocationEnabled(true);
    // Check if we were successful in obtaining the map.
    if (mMap != null) {
        setUpMap();

    }
    }

}

private void setUpMap() {
mMap.addMarker(new.MarkerOptions().position(new LatLng(0, 0)).title("Marker").snippet("Snippet"));
mMap.setMyLocationEnabled(true);
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);

if (location != null) {

    LatLng target = new LatLng(location.getLatitude(), location.getLongitude());
    CameraPosition position = this.mMap.getCameraPosition();

    CameraPosition.Builder builder = new CameraPosition.Builder();
    builder.zoom(15);
    builder.target(target);

    this.mMap.animateCamera(CameraUpdateFactory.newCameraPosition(builder.build()));
    mMap.addMarker(new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("You are here!").snippet("Consider yourself located"));
}
}
}

第2部分

CAGradientLayer

Answer 2

Sub mySub()
  On Error GoTo CatchError 'I called it CatchError but you can call it whatever

  '--All of your code here including "If MsgBox("File has been updated", vbinformatoin) = ok Then Exit Sub"

CatchError:
  'Here put what you want to do in case of an error, for example
  'MsgBox "The code stopped because of an error"
End Sub

只需改变这两种方法

Android Studio Google Maps当我打开我的应用程序时，如何将相机重定向到我当前的位置

2 个答案: