Hai 是 android 应用程序的新手，我正在尝试使用广播接收器获取纬度和经度。但是我的应用程序正在强制关闭。我不知道为什么会发生这种情况。任何人都可以纠正我的错误。
@Override
public void onClick(View v)
{
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the locatioin provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
// Initialize the location fields
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
float lat = (float) (location.getLatitude());
float lng = (float) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
} else {
latituteField.setText("provider not available");
longitudeField.setText("provider not available");
}
registerReceiver(receiver,new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
}
});
private class ConnectivityReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
NetworkInfo info = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if(null != info)
{
String state = getNetworkStateString(info.getState());
String stateString = info.toString().replace(',', '\n');
if(state.equals("Connected")){
result();
}
}
}
}
@Override
protected void onResume() {
super.onResume();
//locationManager.requestLocationUpdates(provider,1000, 1, this);
locationManager.requestLocationUpdates(
provider,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
this
);
}
/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
float lat = (float) (location.getLatitude());
float lng = (float) (location.getLongitude());
longitudeField.setText(String.valueOf(lng));
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
Toast.makeText(this, "Disenabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
protected void Display(Cursor c) {
Toast.makeText(this, "rowid: " + c.getString(0) + "\n" +
"Latitude: " + c.getString(1) + "\n" + "Longitude: " + c.getString(2) + "\n" +
Toast.LENGTH_LONG, 0).show();
}
**updata Logcat Error Message**
"01-06 12:08:27.376: ERROR/AndroidRuntime(9725): java.lang.RuntimeException: Unable to resume activity {com.varma.samples.conntest/com.varma.samples.conntest.MainActivity}: java.lang.NullPointerException
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3133)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3148)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2689)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.access$2300(ActivityThread.java:126)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2038)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.os.Handler.dispatchMessage(Handler.java:99)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.os.Looper.loop(Looper.java:123)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.main(ActivityThread.java:4632)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at java.lang.reflect.Method.invokeNative(Native Method)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at java.lang.reflect.Method.invoke(Method.java:521)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at dalvik.system.NativeStart.main(Native Method)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): Caused by: java.lang.NullPointerException
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at com.varma.samples.conntest.MainActivity.onResume(MainActivity.java:158)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1149)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.Activity.performResume(Activity.java:3823)
01-06 12:08:27.376: ERROR/AndroidRuntime(9725): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3123)
"
我的 list 文件*更新*
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.varma.samples.conntest"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="8" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /> </manifest>
最佳答案
移动线
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
从onclick方法到oncreate方法
关于android - 在android应用程序中使用BroadCastReceiver获取经纬度？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8767870/