How to make a horizontal line in Android application example code

Jak povolit komentáře je přihlášeným uživatelům.
Spam v komentářích je nepříjemný a zatěžuje server. Jednou z metod, jak jej omezit je povolit přidávat komentáře jen registrovaným členům. Toho ve Wordpress dosáhneme v administraci z menu Settings - Discussion kde zaškrtneme políčko Users must be registered and logged in to comment a nastaveni uložíme.

Code with error:

ImageView imgV = (ImageView)findViewById(R.id.myView);
        imgV.setLayoutParams(new ViewGroup.LayoutParams(
        		ViewGroup.LayoutParams.WRAP_CONTENT,
        		0));

If you get error try this code:

        ViewGroup.LayoutParams layoutParams = imgV
				.getLayoutParams();
		layoutParams.height = 0;
		imgV.setLayoutParams(layoutParams);

java.lang.ClassCastException: android.view.ViewGroup$LayoutParams
at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:659)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:311)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
at android.view.View.measure(View.java:8313)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
at android.view.View.measure(View.java:8313)

Problemi is in e.getMessage() what can return null and Log.e (String tag, String msg) will throws an new exception !!!!
Problem and solution:

      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (ArrayIndexOutOfBoundsException e) {
      		String s = e.toString(); // s == java.lang.ArrayIndexOutOfBoundsException
                // try to testing String s for null value
      		if(s != null)
      		 Log.e("bla", s);
      		else 
      		 Log.e("bla", "My error text 1");
      		
      		String s2 = e.getMessage(); // s2 == null !!!!!!!
                // you need to testing String s2 for null value , or you get FATAL EXCEPTION: main
                // and application will be crashed
       		String s2 = e.getMessage(); // s2 == null !!!!!!!
      		if(s2 != null)
      		 Log.e("bla2", e.getMessage());
      		else 
      		 Log.e("bla2", "My error text 2");
     		
                // this is OK
      		e.printStackTrace();
      	}

LogCat:

E/bla(855): java.lang.ArrayIndexOutOfBoundsException

 E/bla2(855): My error text 2

 W/System.err(855): java.lang.ArrayIndexOutOfBoundsException
 W/System.err(855): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
 W/System.err(855): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
 W/System.err(855): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
 W/System.err(855): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
 W/System.err(855): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
 W/System.err(855): 	at android.os.Handler.dispatchMessage(Handler.java:99)
 W/System.err(855): 	at android.os.Looper.loop(Looper.java:123)
 W/System.err(855): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
 W/System.err(855): 	at java.lang.reflect.Method.invokeNative(Native Method)
 W/System.err(855): 	at java.lang.reflect.Method.invoke(Method.java:507)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
 W/System.err(855): 	at dalvik.system.NativeStart.main(Native Method)

Or you can using this code:

      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (Exception e) {
      		
      		
      		StringBuilder sb = new  StringBuilder().append(e.getClass().getSimpleName()); 
          if  (e.getMessage() != null) { 
              sb.append("

"); 
              sb.append(e.getMessage()); 
          } 
          Log.e("err", sb.toString()); // E/err(336): ArrayIndexOutOfBoundsException

          // this code write out all message
          Log.e("myError", "methodName", e);
       }
// E/myError(371): methodName
// E/myError(371): java.lang.ArrayIndexOutOfBoundsException
// E/myError(371): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
// E/myError(371): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
// E/myError(371): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
// E/myError(371): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
// E/myError(371): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
// E/myError(371): 	at android.os.Handler.dispatchMessage(Handler.java:99)
// E/myError(371): 	at android.os.Looper.loop(Looper.java:123)
// E/myError(371): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
// E/myError(371): 	at java.lang.reflect.Method.invokeNative(Native Method)
// E/myError(371): 	at java.lang.reflect.Method.invoke(Method.java:507)
// E/myError(371): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
// E/myError(371): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
// E/myError(371): 	at dalvik.system.NativeStart.main(Native Method)

Long press by finger on screen
From dialogue select Widgets
Select your widget
Put your widget on the screen

Video tutorial - to add home screen widgets - Android 2.1

If You create new xml file with prefix _ , for example _style.xml and You to clean project (Project->Clean), than package in folder project\gen will deleted with R.java class and new R.java not be created.

For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.

If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.