完美解决android M上锁屏情况下,禁止pc通过MTP访问手机存储单元

1、问题解决主要文件：/m8976/packages/providers/MediaProvider/src/com/android/providers/media/MtpService.java

需要在MtpService.java中updateDisabledStateLocked 方法添加锁屏情况限制：

final KeyguardManager keyguardManager = (KeyguardManager) getSystemService(
       Context.KEYGUARD_SERVICE);
mMtpDisabled = (keyguardManager.isKeyguardLocked() && keyguardManager.isKeyguardSecure()) || !mUnlocked || !isCurrentUser;

只要锁屏，mMtpDisabled就设置为true。

这样就实现该功能。

2、当解锁时，自动加载手机存储单元：

添加解锁监听

+  private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
+    @Override
+    public void onReceive(Context context, Intent intent) {
+      final String action = intent.getAction();
+      if (Intent.ACTION_USER_PRESENT.equals(action)) {
+        // If the media scanner is running, it may currently be calling
+        // sendObjectAdded/Removed, which also synchronizes on mBinder
+        // (and in addition to that, all the native MtpServer methods
+        // lock the same Mutex). If it happens to be in an mtp device
+        // write(), it may block for some time, so process this broadcast
+        // in a thread.
+        new Thread(new Runnable() {
+          @Override
+          public void run() {
+            synchronized (mBinder) {
+              // Unhide the storage units when the user has unlocked the lockscreen
+              if (mMtpDisabled) {
+                addStorageDevicesLocked();
+                mMtpDisabled = false;
+              }
+            }
+          }}, "addStorageDevices").start();
+      }
+    }
+  };

Android M上发送解锁状态的广播code没有去除，可以查看/m8976/frameworks/base/packages/SystemUI/src/com/android /systemui/keyguard/KeyguardViewMediator.java

在KeyguardViewMediator.java文件中可以看出，在解锁时，发送Intent.ACTION_USER_PRESENT广播，然后在MtpService.java

进行接收，对mMtpDisabled进行处理。