通过暗码去打开/关闭usb debug开关

通过暗码去打开/关闭usb debug开关

通过暗码去打开/关闭usb debug开关
1. Description
2. Analysis
3. Solution
4. Summary

1. Description

通过在dialer输入暗码，打开/关闭usb debug开关。
其实这个功能本来在settings下面就有的，如果是正式版的设备需要连续点击几次版本号才能将usb debug开关显示出来，通过暗码来打开估计是为了更加方便后续的操作吧。

2. Analysis

1. 首先在dialer处进行逻辑判断，如果接收到的是usb debug开关的暗码，则发送对应的广播。在mtk自带的dialer就有相关的逻辑了，如handleSecretCode方法就会接收*#*#<code>#*#*格式的暗码，然后发送广播，其相关代码如下所示：

   static boolean handleSecretCode(Context context, String input) {
     // Secret codes are accessed by dialing *#*#<code>#*#*
     /// M: add for handle reboot meta secret code @{
     if (FK_SUPPORTED.equals(SystemProperties.get(FK_REBOOT_META_SUPPORT))) {
       if (handleRebootMetaSecretCode(context, input)) {
         return true;
       }
     }
     /// @}
     int len = input.length();
     if (len <= 8 || !input.startsWith("*#*#") || !input.endsWith("#*#*")) {
       return false;
     }
     String secretCode = input.substring(4, len - 4);
     TelephonyManagerCompat.handleSecretCode(context, secretCode);
     return true;
   }
   /*handleSecretCode这个方法在TelephonyManagerCompat.java文件中，它会将输入的暗码以广播的形式发送出去*/
   public static void handleSecretCode(Context context, String secretCode) {
     // Must use system service on O+ to avoid using broadcasts, which are not allowed on O+.
     if (BuildCompat.isAtLeastO()) {
       if (!TelecomUtil.isDefaultDialer(context)) {
         LogUtil.e(
             "TelephonyManagerCompat.handleSecretCode",
             "not default dialer, cannot send special code");
         return;
       }
       context.getSystemService(TelephonyManager.class).sendDialerSpecialCode(secretCode);
     } else {
       // System service call is not supported pre-O, so must use a broadcast for N-.
       Intent intent =
           new Intent(SECRET_CODE_ACTION, Uri.parse("android_secret_code://" + secretCode));
       context.sendBroadcast(intent);
     }
   }

2. 在广播接收器中进行对应的逻辑处理：
   usb debug的状态信息是存储在ContentProvider中的，对应的标识：

        /**
          * Whether ADB is enabled.
          */
         public static final String ADB_ENABLED = "adb_enabled";

   只要将存储在ContentProvider的状态值拿出来，然后进行判断，如果为0则表示当前usb debug是关闭的，如果为1则表示当前usb debug是打开的。只需要将状态值取反后再存入ContentProvider就可以改变usb debug状态。

3. Solution

• 添加USB接收器USBDebugBroadcastReceiver，具体代码如下：

package com.android.settings;
   import android.content.BroadcastReceiver;
   import android.content.ContentResolver;
   import android.content.Context;
   import android.content.Intent;
   import android.content.res.Resources;
   import android.provider.Settings;
   import android.util.Log;
   import android.widget.Toast;
   import com.android.internal.telephony.TelephonyIntents;
   public class USBDebugBroadcastReceiver extends BroadcastReceiver {
       private static final String TAG="USBDebugBroadcastReceiver";
       private Toast debugOpenToast;
       @Override
       public void onReceive(Context context, Intent intent) {
           if(TelephonyIntents.SECRET_CODE_ACTION.equals(intent.getAction()) && "0000".equals(intent.getData().getHost())){
               boolean mEnableAdb = false;
               final ContentResolver mContentResolver = context.getContentResolver();
               mEnableAdb = Settings.Global.getInt(mContentResolver,
                   Settings.Global.ADB_ENABLED, 0) > 0;
               Resources resources=context.getResources();
               if (debugOpenToast != null) {
                   debugOpenToast.cancel();
               }
              if(!mEnableAdb){
                   // make sure the ADB_ENABLED setting value matches the current state
                   try {
                       Settings.Global.putInt(mContentResolver,
                           Settings.Global.ADB_ENABLED, 1 );
                       debugOpenToast = Toast.makeText(context,resources.getString(R.string.enable_adb)+" "+resources.getString(R.string.gadget_state_on)
                           +" "+resources.getString(R.string.band_mode_succeeded),
                               Toast.LENGTH_SHORT);
                       debugOpenToast.show();
                   } catch (SecurityException e) {
                       // If UserManager.DISALLOW_DEBUGGING_FEATURES is on, that this setting can't be changed.
                       Log.d(TAG, "ADB_ENABLED is restricted.");
                       debugOpenToast = Toast.makeText(context,resources.getString(R.string.enable_adb)+" "+resources.getString(R.string.gadget_state_on)
                           +" "+resources.getString(R.string.band_mode_failed),
                               Toast.LENGTH_SHORT);
                       debugOpenToast.show();
                   }
               }else{
                  try {
                       Settings.Global.putInt(mContentResolver,
                           Settings.Global.ADB_ENABLED, 0 );
                       debugOpenToast = Toast.makeText(context,resources.getString(R.string.enable_adb)+" "+resources.getString(R.string.gadget_state_off)
                           +" "+resources.getString(R.string.band_mode_succeeded),
                           Toast.LENGTH_SHORT);
                       debugOpenToast.show();
                   } catch (SecurityException e) {
                       // If UserManager.DISALLOW_DEBUGGING_FEATURES is on, that this setting can't be changed.
                       Log.d(TAG, "ADB_DISENABLED is restricted.");
                       debugOpenToast = Toast.makeText(context,resources.getString(R.string.enable_adb)+" "+resources.getString(R.string.gadget_state_off)
                         +" "+resources.getString(R.string.band_mode_failed),
                         Toast.LENGTH_SHORT);
                       debugOpenToast.show();
                   }
               }
           }
       }
   }

• 在对应的AndroidManifest.xml中为该接收器进行注册，具体如下:

          <receiver android:name=".USBDebugBroadcastReceiver">
              <intent-filter>
                  <action android:name="android.provider.Telephony.SECRET_CODE"/>
                  <data android:scheme="android_secret_code" android:host="33284"/>
              </intent-filter>
          </receiver>

4. Summary

这个问题相对简单，只要将期望的状态只存入对应的ContentProvider中就可与改变usb debug状态。之所以通过广播来处理，是因为与activity相比，通过intent启动指定activity组件时，如果没有找到合适的activity组件，会导致程序异常中止，但是通过intent启动BroadcastReceiver组件时不会有该问题出现。

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