android camera焦距设置,该如何解决

  
         private void initializeZoom() {  

         if (!mParameters.isZoomSupported()) return;  
         // Maximum zoom value may change after preview size is set. Get the  
         // latest parameters here.  
         mParameters = mCameraDevice.getParameters();  
         mZoomMax = mParameters.getMaxZoom();  
         mSmoothZoomSupported = mParameters.isSmoothZoomSupported();  
         mGestureDetector = new GestureDetector(this, new ZoomGestureListener());  
         mCameraDevice.setZoomChangeListener(mZoomListener);  

     }  
 
     ……

------解决方案--------------------

set zoom: mParameters.setZoom(xxx);
set focus mode: setFocusMode(String value);
看看api就明白了的。
http://developer.android.com/reference/android/hardware/Camera.Parameters.html