Pai_^ is a bug in the android framework.

Someone submitted the bug Description: http://code.google.com/p/android/issues/detail? Id = 3484

Symptom: If you add linearlayout as a view to the root directory, but this linearlayout does not have a subview,

The following error is returned during running:

21:50:44 06-18. 020: Error/androidruntime (28605):> JAVA. lang. runtimeexception: mbaselinealignedchildindex of linearlayout> set to an index that is out of bounds.> 21:50:44 06-18. 020: Error/androidruntime (28605): At> android. widget. linearlayout. getbaseline (linearlayout. java: 151)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. linearlayout. measurehorizontal (linearlayout. java: 644)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. linearlayout. onmeasure (linearlayout. java: 280)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. view. measure (view. java: 7712)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. viewgroup. measurechildwithmargins (viewgroup. java: 3044)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. linearlayout. measurechildbeforelayout (linearlayout. java: 888)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. linearlayout. measurevertical (linearlayout. java: 350)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. linearlayout. onmeasure (linearlayout. java: 278)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. view. measure (view. java: 7712)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. viewgroup. measurechildwithmargins (viewgroup. java: 3044)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. framelayout. onmeasure (framelayout. java: 245)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. view. measure (view. java: 7712)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. viewgroup. measurechildwithmargins (viewgroup. java: 3044)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. widget. framelayout. onmeasure (framelayout. java: 245)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. view. measure (view. java: 7712)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. viewroot. extends mtraversals (viewroot. java: 824)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. view. viewroot. handlemessage (viewroot. java: 1774)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. OS. handler. dispatchmessage (handler. java: 99)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. OS. logoff. loop (logoff. java: 123)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> android. app. activitythread. main (activitythread. java: 4321)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> JAVA. lang. reflect. method. invokenative (native method)> 21:50:44 06-18. 020: Error/androidruntime (28605): At> JAVA. lang. reflect. method. invoke (method. java: 521)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> COM. android. internal. OS. zygoteinit $ methodandargscaller. run (zygoteinit. java: 791)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> COM. android. internal. OS. zygoteinit. main (zygoteinit. java: 549)> 06-18 21:50:44. 020: Error/androidruntime (28605): At> Dalvik. system. nativestart. main (native method)

This error occurs because the default value of the member variable in linearlayout is incorrect,

 
/**
* If this layout is part of another layout that is baseline aligned,
* Use the child at this index as the baseline.
*
* Note: This is orthogonal {@ Link# Mbaselinealigned}, which is concerned
* With whether the children of this layout are baseline aligned.
*/
Private IntMbaselinealignedchildindex= 0;
 

2.0 (it is estimated that a revision in the middle has been corrected, but the specific version is not known). Then the SDK fixes this problem:

   /**  
* If this layout is part of another layout that is baseline aligned,
* Use the child at this index as the baseline.
*
* Note: This is orthogonal {  @ Link  # Mbaselinealigned}, which is concerned
* With whether the children of this layout are baseline aligned.
  */  
@ Viewdebug. exportedproperty (Category  =     "  Layout "  )
  Private     Int  Mbaselinealignedchildindex  =     -  1  ; 

:-), It is a problem caused by a default value. In this case, the linearlayout can be used instead of the View control.

The exception is thrown:

 @ Override
  Public     Int Getbaseline (){
  If  (Mbaselinealignedchildindex  <     0  ){
  Return     Super  . Getbaseline ();
}

  If  (Getchildcount ()  <=  Mbaselinealignedchildindex ){
  Throw    New  Runtimeexception (  "  Mbaselinealignedchildindex of linearlayout  "  
  +     "  Set to an index that is out of bounds.  "  );
}

  Final  View child  = Getchildat (mbaselinealignedchildindex );
  Final     Int  Childbaseline  =  Child. getbaseline ();
...