我開發了簡單的應用程序來顯示android的經度和緯度......但它顯示空指針異常...請讓我知道什麼是錯誤..如何在經緯度android
我Activity類
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.Toast;
public class SignalStrengthActivity extends Activity implements LocationListener{
private LocationManager locationManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
@Override
protected void onResume() {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 1, this);
super.onResume();
}
@Override
protected void onPause() {
locationManager.removeUpdates(this);
super.onPause();
}
@Override
public void onLocationChanged(Location location) {
if (location != null) {
Toast.makeText(this, "Latitude and Longitude " + location.getLatitude() + " " +
location.getLongitude(), Toast.LENGTH_SHORT).show();
}
}
@Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Latitude and Longitude Offline ", Toast.LENGTH_SHORT).show();
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
我的清單文件: -
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.latitudelongitude"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="16" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.latitudelongitude.SignalStrengthActivity"
android:configChanges="orientation|keyboardHidden|screenSize"
android:label="@string/app_name"
android:theme="@style/FullscreenTheme" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
當我執行它不會顯示任何應用..表明該位置對象爲空...認罪SE讓我知道如何通過下面的鏈接解決問題
你在哪裏執行呢?在模擬器或設備?仿真器不顯示緯度值,在設備中,您需要啓用GPS以測試上述代碼。 – Raynold 2013-03-26 10:38:33
你需要在真實設備上檢查它並確保GPS已打開 – 2013-03-26 10:53:29
Raynold說的是正確的。您應該在啓用GPS的真實設備上進行測試。請注意,GPS可能需要一段時間才能獲得第一次修復。如果你想在仿真器上測試它,那麼你必須發送位置座標給仿真器。檢查此鏈接如何將座標發送到模擬器:http://android-er.blogspot.in/2009/11/change-gps-location-of-android-emulator.html – Nitish 2013-03-26 10:56:23