java - 添加暂停和恢复 addCircle 到 map api v2

Question

我编写了这个小应用程序，通过使用 map api v2 方法 addCircle 添加圆圈来跟踪我在田间用喷雾器覆盖的区域。我已经弄清楚如何使用 OnClickListener 和 map.clear 方法清除 map 。

我希望能够停止使用 onclicklistener 添加圆圈(暂停)并继续使用 onclicklistener 添加圆圈。任何人都知道这可能会是什么样子集成到我的代码中:

public class MainActivity extends Activity implements LocationListener, OnClickListener {


GoogleMap mMap;
Location myLocation;
EditText length;
String lengthString;
LocationManager locationmanager;

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

    Button start = (Button)findViewById(R.id.button1);
    start.setOnClickListener(this);

    Button clear = (Button)findViewById(R.id.button2);
    clear.setOnClickListener(this);

     mMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

    if (mMap!= null) {

    mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

    mMap.setMyLocationEnabled(true);
    mMap.animateCamera(CameraUpdateFactory.zoomBy(17));}

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub



    LocationManager locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);


    locationmanager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);

     length = (EditText) findViewById(R.id.editText1); 

        lengthString = length.getText().toString();

        if (v.getId() == R.id.button2) { mMap.clear();};

        //if (v.getId() == R.id.buttonPause) {Some pause method}
             //if (v.getId() == R.id.buttonResume) {Some resume method}

}

@Override
public void onLocationChanged(Location location) {



     CircleOptions circleOptions = new CircleOptions()
        .center(new LatLng(location.getLatitude(), location.getLongitude()));
          double bacons = Double.parseDouble(lengthString);

          if (bacons >=0) {

      double radi = bacons * 0.3048;
    circleOptions.radius(radi); // In meters
    circleOptions.fillColor(0xffff0000);
    circleOptions.strokeWidth(0);

          } else { 

        double radi = 20 * 0.3048;
    circleOptions.radius(radi); // In meters
    circleOptions.fillColor(0xffff0000);
    circleOptions.strokeWidth(0);

    }
          mMap.addCircle(circleOptions);   

}

更新我添加了这些 boolean if 语句:

            if (v.getId() == R.id.button1) {setIt = true;};
        if (v.getId() == R.id.button2) { mMap.clear();};
        if (v.getId() == R.id.buttonPauseIt) { setIt = false;};
        if (v.getId() == R.id.buttonResume) { setIt = true;};

到 onClick(View v) 但是我不认为它们被传递给我的

 if (setIt == true){
          mMap.addCircle(circleOptions);} 

在我的 OnLocationChanged 中找到，因为它不会停止使用暂停按钮添加圆圈。

我该如何通过这个？这是我所拥有的:

public class MainActivity extends Activity implements LocationListener, OnClickListener {


GoogleMap mMap;
Location myLocation;
EditText length;
String lengthString;
LocationManager locationmanager;
boolean setIt = true;


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

    Button start = (Button)findViewById(R.id.button1);
    start.setOnClickListener(this);

    Button clear = (Button)findViewById(R.id.button2);
    clear.setOnClickListener(this);

    Button resumeIt = (Button)findViewById(R.id.buttonResume);

    Button pauseIt = (Button)findViewById(R.id.buttonPauseIt);



     mMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

    if (mMap!= null) {

    mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);


    mMap.setMyLocationEnabled(true);
    mMap.animateCamera(CameraUpdateFactory.zoomBy(17));}

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub



    LocationManager locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);


    locationmanager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);



     length = (EditText) findViewById(R.id.editText1); 


        lengthString = length.getText().toString();


        if (v.getId() == R.id.button1) {setIt = true;};
        if (v.getId() == R.id.button2) { mMap.clear();};
        if (v.getId() == R.id.buttonPauseIt) { setIt = false;};
        if (v.getId() == R.id.buttonResume) { setIt = true;};


}

@Override
public void onLocationChanged(Location location) {



     CircleOptions circleOptions = new CircleOptions()
        .center(new LatLng(location.getLatitude(), location.getLongitude()));
          double bacons = Double.parseDouble(lengthString);

          if (bacons >=0) {

      double radi = bacons * 0.3048;
    circleOptions.radius(radi); // In meters
    circleOptions.fillColor(0xffff0000);
    circleOptions.strokeWidth(0);

          } else { 

        double radi = 20 * 0.3048;
    circleOptions.radius(radi); // In meters
    circleOptions.fillColor(0xffff0000);
    circleOptions.strokeWidth(0);

    }
          if (setIt == true){
          mMap.addCircle(circleOptions);}   

}

Answer 1

只需设置一个 boolean 值，如果停止则不要运行添加圆圈的代码。如果它没有停止，则运行代码...

编辑

让我在这里指出一些提示，因为你的代码风格很糟糕

永远不要这样做

if (setIt == true)

这就像说 if true == true 只需执行 if(setIt)

所有这些东西

if (v.getId() == R.id.button1) {setIt = true;};
    if (v.getId() == R.id.button2) { mMap.clear();};
    if (v.getId() == R.id.buttonPauseIt) { setIt = false;};
    if (v.getId() == R.id.buttonResume) { setIt = true;};

您应该使用 if/else 语句，但最好使用基于 View id 的 switch 语句。内联 is 语句也很难阅读，当您想要调试时，您可以正确地单步调试代码。

现在回到你的问题......在你的 onLocationChanged 中你必须这样做......

if (setIt){
    //all code for plotting circles goes here
}else{
    //do something when you dont want to plot or just dont use an else
}

浏览一下您的代码，看看发生了什么。