我在尝试使用 Android 中的 MapView 使用从读取 JSON 结构获得的值来显示地图上的点时遇到上述错误。该地图完美运行并显示测试点,即我手动设置的值,但是当我初始化格式化为 JSON 结构的字符串时,它给出了错误“无法找到 com.google.settings 的提供程序信息”,然后尝试从中读取值。
注意:我已经拥有并且正在使用 Google 地图 API 密钥。我还设置了互联网权限。我能够使用 HttpGet 请求连接到网站并从那里检索 JSON 结构。如果我使用 JSON 读取代码取出 try/catch,则地图会正确显示,否则会出现上述错误。
这是代码:
package com.android.google.maps;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONObject;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.LinearLayout;
public class PointMap extends MapActivity {
/** variables */
LinearLayout linearLayout;
MapView mapView;
List<Overlay> mapOverlays;
Drawable drawable;
PointsItemizedOverlay itemizedOverlay;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapOverlays = mapView.getOverlays();
drawable = this.getResources().getDrawable(R.drawable.androidmarker);
itemizedOverlay = new PointsItemizedOverlay(drawable);
//test points
GeoPoint point = new GeoPoint(19240000,-99120000);
OverlayItem overlayitem = new OverlayItem(point, "", "");
itemizedOverlay.addOverlay(overlayitem);
GeoPoint point2 = new GeoPoint(35410000, 139460000);
OverlayItem overlayitem2 = new OverlayItem(point2, "", "");
itemizedOverlay.addOverlay(overlayitem2);
String jStringTest = "{\"points\": [{\"id\": 00001, \"latitude\": 45.721535000000003, \"longitude\": -78.957449999999994}," +
" {\"id\": 00002, \"latitude\": 39.722852000000003, \"longitude\": -56.008089999999996}]}";
try {
JSONObject jObject = new JSONObject(jStringTest);
JSONArray pointArray = jObject.getJSONArray("points");
for (int i = 0; i < pointArray.length(); i++) {
String pointId = pointArray.getJSONObject(i).getString("id");
double pointLatitude = pointArray.getJSONObject(i).getDouble("latitude");
double pointLongitude = pointArray.getJSONObject(i).getDouble("longitude");
GeoPoint point3 = new GeoPoint((int) (pointLatitude*Math.pow(10, 6)), (int) (pointLongitude*Math.pow(10, 6)));
OverlayItem overlayitem3 = new OverlayItem(point3, "", "");
itemizedOverlay.addOverlay(overlayitem3);
}
} catch (Exception e) {System.out.println("Exception");};
mapOverlays.add(itemizedOverlay);
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
}