Android N获取外置SD卡或挂载U盘路径的方法

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我是靠谱客的博主寒冷皮皮虾，这篇文章主要介绍Android N获取外置SD卡或挂载U盘路径的方法，现在分享给大家，希望可以做个参考。

在Android N上并没有提供直接的方法获取外置SD卡或挂载U盘路径，可以通过下面方法获取内置sd卡路径

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Environment.getExternalStorageDirectory().getAbsolutePath();

通过查看getExternalStorageDirectory源码发现，Android只是没有公开的接口获取而已

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public static File getExternalStorageDirectory() {
  throwIfUserRequired();
  return sCurrentUser.getExternalDirs()[0];
 }

内置sd卡取的sCurrentUser.getExternalDirs()中的第一个值，通过查看StorageManager公有的方法，发下StorageManager@getStorageVolumes也能获取到所有的StorageVolume，但是通过StorageVolume对象只能调用到一些简单的方法，发现StorageVolume有很多隐藏方法如下：

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frameworks/base/core/java/android/os/storage/StorageVolume.java
 /**
  * Returns true if the volume is removable.
  *
  * @return is removable
  */
 public boolean isRemovable() {
  return mRemovable;
 }
 
 /**
  * Returns the mount path for the volume.
  *
  * @return the mount path
  * @hide
  */
 public String getPath() {
  return mPath.toString();
 }
 
 /** {@hide} */
 public File getPathFile() {
  return mPath;
 }

竟然没有公开的接口调用这些方法，那就只能想到反射了，具体实现方式如下：

1、在清掉AndroidManifest.xml文件中添加需要的权限

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<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

2、通过反射获取外置SD卡或挂载U盘路径

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private StorageManager mStorageManager;
  mStorageManager = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
  //获取所有挂载的设备（内部sd卡、外部sd卡、挂载的U盘）
  List<StorageVolume> volumes = mStorageManager.getStorageVolumes();
  try {
   Class<?> storageVolumeClazz = Class
     .forName("android.os.storage.StorageVolume");
   //通过反射调用系统hide的方法
   Method getPath = storageVolumeClazz.getMethod("getPath");
   Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
   for (int i = 0; i < volumes.size(); i++) {
    StorageVolume storageVolume = volumes.get(i);//获取每个挂载的StorageVolume
    
    //通过反射调用getPath、isRemovable
    String storagePath = (String) getPath.invoke(storageVolume); //获取路径
    boolean isRemovableResult = (boolean) isRemovable.invoke(storageVolume);//是否可移除
    String description = storageVolume.getDescription(this);
    Log.d("jason", " i=" + i + " ,storagePath=" + storagePath
      + " ,isRemovableResult=" + isRemovableResult +" ,description="+description);
   }
  } catch (Exception e) {
   Log.d("jason", " e:" + e);
  }

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private StorageManager mStorageManager;
  mStorageManager = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
  //获取所有挂载的设备（内部sd卡、外部sd卡、挂载的U盘）
  List<StorageVolume> volumes = mStorageManager.getStorageVolumes();
  try {
   Class<?> storageVolumeClazz = Class
     .forName("android.os.storage.StorageVolume");
   //通过反射调用系统hide的方法
   Method getPath = storageVolumeClazz.getMethod("getPath");
   Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
   for (int i = 0; i < volumes.size(); i++) {
    StorageVolume storageVolume = volumes.get(i);//获取每个挂载的StorageVolume
    
    //通过反射调用getPath、isRemovable
    String storagePath = (String) getPath.invoke(storageVolume); //获取路径
    boolean isRemovableResult = (boolean) isRemovable.invoke(storageVolume);//是否可移除
    String description = storageVolume.getDescription(this);
    Log.d("jason", " i=" + i + " ,storagePath=" + storagePath
      + " ,isRemovableResult=" + isRemovableResult +" ,description="+description);
   }
  } catch (Exception e) {
   Log.d("jason", " e:" + e);
  }