maps

问题 I'm trying to develop an Offline maps application using ArcGis android sdk. Followed the tutorials from the ArcGis website.Since it is an Offline Maps Applicaion, I am testing it without an internet connection. But, when I run the application,the MapView is blank. It just shows a black screen. When I checked the Logcat, It says 11-26 14:39:57.757 28520-28520/com.example.lalprakash.offlinearcgismap D/GLSurfaceView: checkGLSurfaceViewlLogProperty get invalid command 11-26 14:39:57.839 28520

问题 Is there an offline Map layer available for Leaflet? I don't need in detail, but basic geometry would be sufficient. 回答1: For sure you can set up your own offline map (raster tiles and/or vector shapes). The difficulty or out-of-the-box availability depends on what kind of information and level of details you want. GeoJSON: The easiest is if you need just world countries borders with little detail, just to get the outline. In that case, you can find GeoJSON files on Internet that contain that

问题 I'm trying to use an explicit intent to display a MapView in my android app. Although I don't see anything wrong with my code, I keep getting a "NoClassDefFoundError" when I try to start my activity. Basically, from my main activity (SetCriteria), I create the explicit intent when user presses a button : Log.i(TAG, "Showing map.."); try{ Intent intentMap = new Intent(view.getContext(), AddLocation.class); startActivity(intentMap); }catch(Throwable ex) { Log.e(TAG, "Error occured while trying

问题 I was wondering if there is actually some way to find markers near my position using leaflet.js. The first think to come to my head is to store lat and lng of my position and then iterate over an array of lat and lng markers placing them in an array an then sort that array. I am not sure if this is a good option because if you have a million markers in the map is going to take a while. Pseudo code var myLatLng = [34,56]; var markers = [[20,30],[10,20],[12,-100],[54,90],[-10, -20],[20,20]];

问题 I'm saving the Zoom and Location of the Google Map API setting in cookies as the user adjusts his map. When they come back the map is at the same place. The function works most of the time: var h = JSON.stringify(map.getCenter(), null, 2); jQuery.cookies.set("YD44635center",h,cookieOptions); On the decode side using: locationVar = jQuery.cookies.get("YD44635center"); var temp = ""; // for testing: for(var x in locationVar){ temp += x + "\n"; } alert(temp); To see what I'm getting, most of the

问题 The code below is creating a new map called nameTable , then adding an entry named example to it, then trying to print the name property of the Value. When I run it, it seems that the plus operation didn't add a new entry to the map like I thought it would. So what am I doing wrong? class Person(name1: String, lastName1: String, age1: Int){ var name: String = name1 var lastName: String = lastName1 var age: Int = age1 } var nameTable: MutableMap<String, Person> = mutableMapOf() var example =

问题 The code below is creating a new map called nameTable , then adding an entry named example to it, then trying to print the name property of the Value. When I run it, it seems that the plus operation didn't add a new entry to the map like I thought it would. So what am I doing wrong? class Person(name1: String, lastName1: String, age1: Int){ var name: String = name1 var lastName: String = lastName1 var age: Int = age1 } var nameTable: MutableMap<String, Person> = mutableMapOf() var example =

问题 Iterator iterator = map.entrySet().iterator(); while (iterator.hasNext()) { Map.Entry mapEntry = (Map.Entry) iterator.next(); System.out.println("The key is: " + mapEntry.getKey() + ",value is :" + mapEntry.getValue()); } This is my code. Now i don't want to use Iterator to get the values. Please help me to find best solution. 回答1: Map<String, Object> map = .....;//Initialization here for (String key : map.keySet()) { // write your code here } //If you are just using keys of the Map for

问题 I want to visualize a dataframe with R and the ggmap package. df: | lon | lat | |-----------|-----------| | 6.585863 | 51.09021 | | 8.682.127 | 50.11092 | | 7.460.367 | 5.152.755 | I created a map with mapImageData <- get_googlemap( + "Germany", + zoom=15 + ) And then wanted to add the geocodes: ggmap(mapImageData) + + geom_point(aes(x=lon, y=lat), data=df, colour="red", size=5) But I get the error: Error: geom_point requires the following missing aesthetics: x, y What am I doing wrong? 回答1:

问题 I am working with the react-google-maps package https://github.com/tomchentw/react-google-maps and https://www.npmjs.com/package/react-google-maps. I have an error that says: ./src/App.js Line 31: 'google' is not defined no-undef Line 32: 'google' is not defined no-undef Line 37: 'google' is not defined no-undef Line 42: 'google' is not defined no-undef Line 44: 'google' is not defined no-undef and heres my line in the error: state = { origin: new google.maps.LatLng(41.8507300, -87.6512600),