我知道周围有类似的问题，但我无法找到一个可靠的答案，这是我的问题：我有没有办法让没有谷歌地图参考的标记存储在ArrayList（或任何其他存储），然后只需将它们添加到我的地图？
背景： 我有一个应用程序，目前有大约3,500个标记。每个标记还有一个与之关联的数据（布尔数组存储每个标记的数据，用于根据用户交互使它们可见/不可见）。目前，我使用扩展AsyncTask的类获取这些标记的位置和数据。加载完成后，我使用主线程上的这些数据创建我的标记。但是，这需要一些时间，并且在创建标记并将其添加到地图时冻结UI。我想在后台以某种方式做到这一点。
到目前为止我尝试了什么： 我创建了另一个扩展AsyncTask的类，它传递了我的LocationData和我的Google Map对象。但是当我尝试在Async类中创建标记时出现错误。我收到运行时错误，说我需要在UI线程上执行此操作。
java.lang.RuntimeException：执行时发生错误 doInBackground（）
引起：com.google.maps.api.android.lib6.common.apiexception.c：不 在主线程上
我还考虑过在后台制作MarkerOptions对象，然后用它在主线程中创建标记;但是，我无法在MarkerOption中添加标签，需要将其添加到标记中。在这种情况下，我需要在主线程中再次浏览所有这些，只是为了添加标签，我觉得这不会为我节省太多时间/资源。
如何创建这些标记并附加其标记而不阻止UI，我们将不胜感激任何建议/帮助？
提前致谢。
以下是我的一些代码：
LocationLoader类 （BinLocation是我的Location类，每个对象都有布尔变量（标记标记）和LatLng） 公共类LocationLoader扩展AsyncTaskLoader＆gt; {
private String TAG = LocationLoader.class.getName();
String[] fileNameArray;
//ArrayLists
private ArrayList<BinLocation> mBinLocationArrayList = new ArrayList<>();
public LocationLoader(Context context, String... fileNames){
super(context);
//get the file names that was passed in
fileNameArray = fileNames;
}//LocationLoader
@Override
protected void onStartLoading() {
Log.v(TAG, "onStartLoading called");
forceLoad();
}//onStartLoading
@Override
public ArrayList<BinLocation> loadInBackground() {
Log.v(TAG, "loadInBackground called");
String path = "/storage/emulated/0/";
File file;
String output = "";
//Read data from file
for (int i = 0; i < fileNameArray.length; i++) {
file = new File(path + fileNameArray[i]);
try (Scanner scanner = new Scanner(file)) {
//first line of the text, containing the location and version
output = scanner.nextLine();
String prefix = (output.split(":"))[0];
String line;
while (scanner.hasNextLine()) {
line = scanner.nextLine();
String inputArray[] = line.split(",");
BinLocation binLocation = new BinLocation(
prefix + "-" + inputArray[0],
Double.parseDouble(inputArray[1]),
Double.parseDouble(inputArray[2]),
Integer.parseInt(inputArray[3].trim()),
Integer.parseInt(inputArray[4].trim()),
Integer.parseInt(inputArray[5].trim()),
Integer.parseInt(inputArray[6].trim()));
mBinLocationArrayList.add(binLocation);
}//while
} catch (Exception e) {
Log.e(TAG, "File read error: ", e);
}
}//for
Log.v(TAG, "readLocation finished");
Log.v(TAG, "ArrayList size: " + mBinLocationArrayList.size());
return mBinLocationArrayList;
}//loadInBackground
}//LocationLoader class
这是我的MarkerLoader类（我试过这个并得到了doInBackground（）错误）。此外，现在没有代码可以将数据添加到标记中，但是在将其添加到地图后它就会在循环中出现问题。
public class MarkerLoader extends AsyncTaskLoader<ArrayList<Marker>> {
private GoogleMap map;
private ArrayList<Marker> mMarkerArrayList = new ArrayList<>();
private ArrayList<MyLocation> mBinLocationArrayList = new ArrayList<>();
public MarkerLoader (Context context, GoogleMap map, ArrayList<BinLocation> binLocationArrayList) {
super(context);
this.map = map;
this.mBinLocationArrayList = binLocationArrayList;
}//MarkerLoader
@Override
protected void onStartLoading() {
Log.v(TAG, "onStartLoading called");
forceLoad();
}//onStartLoading
@Override
public ArrayList<Marker> loadInBackground() {
Log.v(TAG, "loadInBackground called");
Marker marker;
for (BinLocation binLocation : mMyLocationArrayList) {
marker = map.addMarker(new MarkerOptions()
.position(binLocation.getPosition()));
mMarkerArrayList.add(marker);
}
Log.v(TAG, "loadInBackground finished, with: " + mMarkerArrayList.size());
return mMarkerArrayList;
}
}
这是主Activity中的辅助函数（populateMap（）），它生成标记并将它们保存在ArrayList中
private void populateMap() {
if (!checkMapReady() || !mMapIsEmpty) {
return;
}//if Map Not ready
//Initialize ArrayList
mMarkerArrayList = new ArrayList<>();
/**
* This part uses the loop to go through each MyLocation object in the ArrayList, extract
* all the data, and set the markers
*/
//Check to make sure the BinLocation ArrayList is not empty otherwise we will crash
if (mBinLocationArrayList.isEmpty()) {
Log.w(TAG, "populateMap() terminated, mBinLocationArrayList empty");
return;
}//if BinLocation empty
//Safety check to clear the map before populating it
mMap.clear();
//create a markerMyLocation object
Marker mMaker;
//This goes through the ArrayList for every MyLocation object and sets up the markerMyLocation
for (BinLocation binLocation : mBinLocationArrayList) {
//get boolean values
boolean[] booleanValues = {binLocation.getGarbage(), binLocation.getContainer(),
binLocation.getPaper(), binLocation.getCompost()};
//Set different icon
switch (markerIconPreference) {
case "customIcon":
//custom icon
//Decide what icon to use
if (booleanValues[0] && !booleanValues[1] && !booleanValues[2] && !booleanValues[3]) {
//Make a new MarkerOptions object to add the data
//garbage markers
mMaker = mMap.addMarker(new MarkerOptions()
.title(binLocation.getId())
.position(binLocation.getPosition())
.icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_garbage))
.visible(garbageVisible));
} else {
//Make a new MarkerOptions object to add the data
//recycling markers
mMaker = mMap.addMarker(new MarkerOptions()
.title(binLocation.getId())
.position(binLocation.getPosition())
.icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_recycling))
.visible(recyclingVisible));
}
//Add our boolean array as an object to our markerMyLocation
mMaker.setTag(booleanValues);
//Add the markerMyLocation to the ArrayList
mMarkerArrayList.add(mMaker);
break;
case "coloredTeardrop":
//teardrop icon
//Decide what icon to use
if (booleanValues[0] && !booleanValues[1] && !booleanValues[2] && !booleanValues[3]) {
//Make a new MarkerOptions object to add the data
//garbage markers
mMaker = mMap.addMarker(new MarkerOptions()
.title(binLocation.getId())
.position(binLocation.getPosition())
.visible(garbageVisible));
} else {
//Make a new MarkerOptions object to add the data
//recycling markers
mMaker = mMap.addMarker(new MarkerOptions()
.title(binLocation.getId())
.position(binLocation.getPosition())
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN))
.visible(recyclingVisible));
}
//Add our boolean array as an object to our markerMyLocation
mMaker.setTag(booleanValues);
//Add the markerMyLocation to the ArrayList
mMarkerArrayList.add(mMaker);
break;
}//switch
}//for
//disable the progress bar
mProgressBar.setVisibility(View.GONE);
//De-activate the CountDown timer since the map is ready
mCountDownTimer.cancel();
//set the boolean to false
mMapIsEmpty = false;
Log.v(TAG, "populateMap finished. Markers: " + mMarkerArrayList.size());
}//populateMap
这是onMapReady函数
public void onMapReady(GoogleMap map) {
Log.v(TAG, "onMapReady called");
mMap = map;
//Setup on map loaded
mMap.setOnMapLoadedCallback(this);
//Check to see if the map is empty and the location array list is not empty and then call populateMap
if (mMapIsEmpty && !mBinLocationArrayList.isEmpty()) {
populateMap();
}//if map empty
//set bounds
mMap.setLatLngBoundsForCameraTarget(GREATER_VANCOUVER_BOUND);
//Set min zoom level to match the bound
mMap.setMinZoomPreference(10.0f);
//disable map toolbar
UiSettings mUiSettings = mMap.getUiSettings();
mUiSettings.setMapToolbarEnabled(false);
//Set listeners
mMap.setOnMarkerClickListener(this);
mMap.setOnInfoWindowCloseListener(this);
mMap.setOnInfoWindowClickListener(this);
// Setting our custom info window, passing out helper method
mMap.setInfoWindowAdapter(new CustomInfoWindowAdapter());
//Here we check for permission and setup the map accordingly
if (!checkLocationPermission()) {
//Permission is not granted, log, and use the default location
Log.v(TAG, "No location permission");
//setup default map
defaultMapSetup();
} else {
Log.v(TAG, "Location permission granted");
//Enable my location and initialize the map there
mMap.setMyLocationEnabled(true);
//Setup the map
locationMapSetup();
}//if -permission
}//onMapReady
答案 0 :(得分：0)
尝试在另一个线程中创建标记
const response = function*() {
yield takeEvery(action => (action.type === "CLIENT_RESPONSE" && !action.error), handleResponse);
}