Reputation: 23
i have made this sample process application but cant get to run it i keep getting this null pointer exception please tell me how to solve it and why am i having it
my main activity class:
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class SimpleServiceController extends Activity {
Button start1 = (Button)findViewById(R.id.start);
Button stop1 = (Button)findViewById(R.id.stop);
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
start1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
startService(new Intent(SimpleServiceController.this,Service1.class));
}
});
stop1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
stopService(new Intent(SimpleServiceController.this,Service1.class));
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
my service class
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.widget.Toast;
public class Service1 extends Service {
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
super.onCreate();
Toast.makeText(this,"Service created ...", Toast.LENGTH_LONG).show();
}
@Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service destroyed ...", Toast.LENGTH_LONG).show();
}
}
my maifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="dom.example.serviceapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".SimpleServiceController"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".Service1" ></service>
</application>
please tell me where am i wrong.
Upvotes: 0
Views: 118
Reputation: 328
Try to return a binder on bind(),
instead of null
.
Eg:
// onbind example:
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
// This is the object that receives interactions from clients. See
// RemoteService for a more complete example.
private final IBinder mBinder = new LocalBinder();
Upvotes: 0
Reputation: 8101
Initialization of Buttons should be inside onCreate()
method, just after setContentView()
start1 = (Button)findViewById(R.id.start);
stop1 = (Button)findViewById(R.id.stop);
findViewById
will not work unless you set the content view.
Upvotes: 6