現在網上關於外接SD Card路徑的文章大多已經過時，現將相關介面/方法的使用和得到的實際路徑貼在下面，供大家參考之用，尤其要注意getExternalStorageDirectory不再是外接SD卡的路徑了，而是一個內建的虛擬SD卡，並且對於多使用者來講，後面帶一個數字來區分使用者路徑，主使用者id為0，相關說明見連結文件，另附一篇SD  mount的文章連結，雖然也算過時了，但框架和分析問題的思路還在。

log：

05-31 09:54:00.009 6445-6445/? D/MainActivity: getSdDirectory2  [email protected]
05-31 09:54:00.010 6445-6445/? D/MainActivity: getSdDirectory2  getVolumeList=public android.os.storage.StorageVolume[] android.os.storage.StorageManager.getVolumeList()
05-31 09:54:00.015 6445-6445/? D/MainActivity: getSdDirectory2  length=2
05-31 09:54:00.015 6445-6445/? D/MainActivity: getSdDirectory2 path=/storage/emulated/10  removable=false getState=mounted
05-31 09:54:00.015 6445-6445/? D/MainActivity: getSdDirectory2 path=/storage/56A1-9404  removable=true getState=mounted
05-31 09:54:00.028 6445-6445/? D/MainActivity: getExternalStorageDirectory =/storage/emulated/10
05-31 09:54:00.029 6445-6445/? D/MainActivity: getRootDirectory =/system

code：

             StorageVolume[] volumes = null;

             Object invokeVolumeList = null;

             Method getVolumeList= null;

              mStorageManager = (StorageManager)context.getSystemService(Context.STORAGE_SERVICE);

              try {

           Log.d(TAG, "getSdDirectory2  mStorageManager="+mStorageManager);


                getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
                Log.d(TAG, "getSdDirectory2  getVolumeList="+getVolumeList);

                  try

{

                   final Class<?>storageValumeClazz = Class.forName("android.os.storage.StorageVolume");

                   final MethodgetPath= storageValumeClazz.getMethod("getPath");

                   Method isRemovable = storageValumeClazz.getMethod("isRemovable");

                   Method mGetState = null

;

                   if (Build.VERSION.SDK_INT >Build.VERSION_CODES.KITKAT) {

                      try {

                           mGetState = storageValumeClazz.getMethod("getState");

                       } catch(NoSuchMethodException e) {

                           e.printStackTrace();

                       }

                   }

                      try {

                          invokeVolumeList= getVolumeList.invoke(mStorageManager);

                      }catch (Exception e) {

                            Log.e(TAG,"couldn't talkto volumes", e);

                       }

                       final int length = Array.getLength(invokeVolumeList);

                      Log.d(TAG,"getSdDirectory2 length="+length);

                      ArrayList<StorageBean> list = newArrayList<StorageBean>();

                      for(int i = 0; i<length ;i++) {

                          final Object storageValume= Array.get(invokeVolumeList, i);//

                         final String path =(String) getPath.invoke(storageValume);

                         final boolean removable =(Boolean) isRemovable.invoke(storageValume);

                         String state = null;

                         if (mGetState !=null) {

                             state = (String) mGetState.invoke(storageValume);

                         }

                        Log.d(TAG,"getSdDirectory2path="+path+"  removable="+removable+" getState="+state);

                      }

                  } catch (Exception e) {

                     Log.e(TAG,"couldn't talkto MountService", e);

                  }

              } catch(NoSuchMethodException e) {

                 e.printStackTrace();

              }

參考文章：

Android6.0如何判斷有無外接SD卡（TF卡），並讀寫

http://m.blog.csdn.net/article/details?id=52671938

掛載流程：

http://blog.csdn.net/fe421504975/article/details/8240190