我正在开发应用程序,在其中我可以看到地图并在其上放置一些标记并缩放到该位置。
我成功显示了我的地图视图。但是在添加了标记和缩放代码后,它强行关闭...请指导我,我已经给出了下面的代码以及我的日志猫贴。
package com.appeal.my_map;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
public class MainActivity extends FragmentActivity {
private GoogleMap googlemap;
double latitude = 17.385044;
double longitude = 78.486671;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
marker();
CameraPosition cameraPosition = new CameraPosition.Builder().target(
new LatLng(17.385044, 78.486671)).zoom(12).build();
googlemap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
private void marker() {
// TODO Auto-generated method stub
MarkerOptions marker = new MarkerOptions().position(new LatLng(latitude, longitude)).title("Hello Maps ");
googlemap.addMarker(marker);
googlemap.setMyLocationEnabled(true);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
我的xml文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>
</LinearLayout>
Log Cat
7561 com.appeal.my_map AndroidRuntime FATAL EXCEPTION: main
7561 com.appeal.my_map AndroidRuntime java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appeal.my_map/com.appeal.my_map.MainActivity}: java.lang.NullPointerException
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2343)
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread.access$600(ActivityThread.java:162)
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
7561 com.appeal.my_map AndroidRuntime at android.os.Handler.dispatchMessage(Handler.java:107)
7561 com.appeal.my_map AndroidRuntime at android.os.Looper.loop(Looper.java:194)
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread.main(ActivityThread.java:5371)
7561 com.appeal.my_map AndroidRuntime at java.lang.reflect.Method.invokeNative(Native Method)
7561 com.appeal.my_map AndroidRuntime at java.lang.reflect.Method.invoke(Method.java:525)
7561 com.appeal.my_map AndroidRuntime at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
7561 com.appeal.my_map AndroidRuntime at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
7561 com.appeal.my_map AndroidRuntime at dalvik.system.NativeStart.main(Native Method)
7561 com.appeal.my_map AndroidRuntime Caused by: java.lang.NullPointerException
7561 com.appeal.my_map AndroidRuntime at com.appeal.my_map.MainActivity.marker(MainActivity.java:41)
7561 com.appeal.my_map AndroidRuntime at com.appeal.my_map.MainActivity.onCreate(MainActivity.java:25)
7561 com.appeal.my_map AndroidRuntime at android.app.Activity.performCreate(Activity.java:5122)
7561 com.appeal.my_map AndroidRuntime at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1081)
7561 com.appeal.my_map AndroidRuntime at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
7561 com.appeal.my_map AndroidRuntime ... 11 more
请纠正我哪里出错了... 谢谢......!
答案 0 :(得分:1)
您尚未初始化googlemap
。您需要初始化相同的
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
googlemap = fm.getMap();
答案 1 :(得分:0)
GoogleMap是空的?尝试先初始化GoogleMap,然后添加标记。否则,您将获得NullPointer异常。
googleMap = (GoogleMap)...findViewById(R.id.....);