Android中MediaPlayer类的setVolume方法参数的范围

不知到为什么在开发文档中并没有注明MediaPlayer类的setVolume方法的参数的范围

  
  
  

   
   
   public
   
   
    
   
   
   void
   
   
    setVolume (
   
   
   float
   
   
    leftVolume, 
   
   
   float
   
   
    rightVolume)

Since: API Level 
   
   
   1
   
   
   
Sets the volume on 
   
   
   this
   
   
    player. This API is recommended 
   
   
   for
   
   
    balancing the output of audio streams within an application. Unless you are writing an application to control user settings, 
   
   
   this
   
   
    API should be used in preference to setStreamVolume(
   
   
   int
   
   
   , 
   
   
   int
   
   
   , 
   
   
   int
   
   
   ) which sets the volume of ALL streams of a particular type. Note that the passed volume values are raw scalars. UI controls should be scaled logarithmically.
Parameters

leftVolume left volume scalar
rightVolume right volume scalar
  
  
  

网友们的说法也是很多不同版本，不过经过测试发现和SoundPool的setVolume方法的参数的范围是一样的，也是0.0到1.0

  
  
  

   
   
   public
   
   
    
   
   
   final
   
   
    
   
   
   void
   
   
    setVolume (
   
   
   int
   
   
    streamID, 
   
   
   float
   
   
    leftVolume, 
   
   
   float
   
   
    rightVolume)

Since: API Level 
   
   
   1
   
   
   
Set stream volume. Sets the volume on the stream specified by the streamID. This is the value returned by the play() function. The value must be in the range of 
   
   
   0.0
   
   
    to 
   
   
   1.0
   
   
   . If the stream does not exist, it will have no effect.
Parameters

streamID a streamID returned by the play() function
leftVolume left volume value (range 
   
   
   =
   
   
    
   
   
   0.0
   
   
    to 
   
   
   1.0
   
   
   )
rightVolume right volume value (range 
   
   
   =
   
   
    
   
   
   0.0
   
   
    to 
   
   
   1.0
   
   
   )
  
  
  

一般使用这个100个就行了

  
  
  

   
   
   1 
   
   
    
   
   
   for
   
   
    (
   
   
   float
   
   
    i 
   
   
   =
   
   
    
   
   
   0.01F
   
   
   ; i 
   
   
   <=
   
   
    
   
   
   1.00F
   
   
   ; i 
   
   
   +=
   
   
    
   
   
   0.01F
   
   
   ) {

   
   
   2 
   
   
    System.out.println(
   
   
   new
   
   
    DecimalFormat(
   
   
   "
   
   
   #.##
   
   
   "
   
   
   ).format(i));

   
   
   3 
   
   
    }