title: Save the toggle state using share preference
body: <p>I try to save the toggle state in my application.Here is my code</p>
  
  <pre><code>    boolean on;
  public SharedPreferences spref;
  ToggleButton tb;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      // TODO Auto-generated method stub
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.fb_intermidiate);
      spref = getPreferences(MODE_PRIVATE);
      tb = (ToggleButton) findViewById(R.id.toggleButton1);
      on = spref.getBoolean("On", true);  //default is true
      if (on = true) 
      {
        tb.setChecked(true);
      }       else
      {
        tb.setChecked(false);
      }
      back = (Button)findViewById(R.id.button_back); 
      //back.setText(R.string.back_button_in_settings);
      back.setOnClickListener(new View.OnClickListener() {
  
          public void onClick(View v) {
              // TODO Auto-generated method stub
              finish();
          }
      }); 
  } 
  
  public void onToggleClicked(View view) {
  
      on = ((ToggleButton) view).isChecked();
      if (on) {
          Toast.makeText(this, "On : Notification will be Enabled", Toast.LENGTH_SHORT).show();
          SharedPreferences.Editor editor = spref.edit();
          editor.putBoolean("On", true); // value to store
          editor.commit();
  
      } else {
      Toast.makeText(this, "Off : Notification will be Disabled", Toast.LENGTH_SHORT).show();
          SharedPreferences.Editor editor =spref.edit();
          editor.putBoolean("Off", false); // value to store
          editor.commit();
      }  
  }
  </code></pre>
  
  <p>But Its getting force close.:(</p>
  
  <p>Here is my logcat</p>
  
  <pre><code>07-25 09:02:23.317: E/AndroidRuntime(640): java.lang.RuntimeException: Unable to start       activity ComponentInfo{com.ace.gugulog/com.ace.gugulog.activities.FacebookIntermidiate}: java.lang.NullPointerException
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1815)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at java.lang.reflect.Method.invokeNative(Native Method)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at java.lang.reflect.Method.invoke(Method.java:491)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at dalvik.system.NativeStart.main(Native Method)
  07-25 09:02:23.317: E/AndroidRuntime(640): Caused by: java.lang.NullPointerException
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at  com.ace.gugulog.activities.FacebookIntermidiate.onCreate(FacebookIntermidiate.java:32)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at android.app.Activity.performCreate(Activity.java:4397)
  
  07-25 09:02:23.317: E/AndroidRuntime(640):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
  </code></pre>