我已经制作了这个示例流程应用程序但无法运行它我不断收到这个空指针异常请告诉我如何解决它以及为什么我有它
我的主要活动课:
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;
}
}
我的服务等级
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();
}
}
我的 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>
请告诉我我哪里错了。