我正在尝试在Android应用程序中使用谷歌地图。MainActivity包含EditText、ImageButton和MapView。当用户给出一些查询并点击ImageButton时，MainAcitivity应该从url中获取一些JSON数据，然后当用户点击这些标记时，我需要使用这些JSON数据来创建标记和对话框。每当我运行应用程序时，它都运行得很好。但当我点击ImageButton时，应用程序停止给出logcat错误NetworkOnMainThreadException和StrickMode$AndroidBlockGuardPolicy。我已经附加了logcat输出和MainActivity。我已经运行了这个JSON程序来创建其他测试项目，它运行得很好。但当我把它添加到MainAcitivity时，它就不起作用了。我相信，安卓的安全政策正在阻止它从url获取数据。
那么，出现此错误的原因是什么？如何使"活动"正常工作？非常感谢朋友们的关注。如果您需要CustomOverlayItem对象或JSON对象的更多代码，请告诉我。
public class MainActivity extends MapActivity {
private List<Home> listHome = new ArrayList<Home>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MapView mv_map = (MapView) findViewById(R.id.mv_map);
MapController mapController = mv_map.getController();
mv_map.setBuiltInZoomControls(true);
mapController.setZoom(5);
Markers markers = new Markers(this.getResources().getDrawable(
R.drawable.ic_action_home), this);
CustomOverlayItem items = new CustomOverlayItem(getuserLocation(),
"Checking", "Checking");
List<Overlay> overlays = mv_map.getOverlays();
markers.addOverlayItem(items);
overlays.add(markers);
ImageButton ib_search = (ImageButton) findViewById(R.id.ib_search);
ib_search.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Json json = new Json();
listHome = json.getListHome();
EditText editText = (EditText) findViewById(R.id.et1_search);
editText.setText(listHome.get(0).getTitle().toString());
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
private GeoPoint getuserLocation() {
GeoPoint geoPoint = new GeoPoint(19240000, -99120000);
return geoPoint;
}
}
Logcat输出：错误
08-04 16:26:55.253: E/Trace(1307): error opening trace file: No such file or directory (2)
08-04 16:26:57.743: E/MapActivity(1307): Couldn't get connection factory client
08-04 16:27:01.643: E/AndroidRuntime(1307): FATAL EXCEPTION: main
08-04 16:27:01.643: E/AndroidRuntime(1307): android.os.NetworkOnMainThreadException
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.net.InetAddress.getAllByName(InetAddress.java:214)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:341)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
08-04 16:27:01.643: E/AndroidRuntime(1307): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.net.URL.openStream(URL.java:462)
08-04 16:27:01.643: E/AndroidRuntime(1307): at com.incubers.map.json.Json.getListHome(Json.java:33)
08-04 16:27:01.643: E/AndroidRuntime(1307): at com.incubers.map.MainActivity$1.onClick(MainActivity.java:53)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.view.View.performClick(View.java:4084)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.view.View$PerformClick.run(View.java:16966)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.os.Handler.handleCallback(Handler.java:615)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.os.Handler.dispatchMessage(Handler.java:92)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.os.Looper.loop(Looper.java:137)
08-04 16:27:01.643: E/AndroidRuntime(1307): at android.app.ActivityThread.main(ActivityThread.java:4745)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.lang.reflect.Method.invokeNative(Native Method)
08-04 16:27:01.643: E/AndroidRuntime(1307): at java.lang.reflect.Method.invoke(Method.java:511)
08-04 16:27:01.643: E/AndroidRuntime(1307): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-04 16:27:01.643: E/AndroidRuntime(1307): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-04 16:27:01.643: E/AndroidRuntime(1307): at dalvik.system.NativeStart.main(Native Method)
NetworkOnMainThreadException异常在应用程序尝试在其主线程上执行网络操作时抛出。使用AsyncTask、Handler、HandlerThread从服务器获取Json
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
.detectAll()
.penaltyLog()
.penaltyDialog()
.build());
请参阅此
您还可以避免主thread/上的IO相关任务
使用处理程序、AsyncTask并在UI上发布结果。