Android AccessibilityService研究

AccessibilityService开启方式

. 在Framework里直接添加对应用app 服务component。

loadSetting(stmt, Settings.Secure.ACCESSIBILITY_ENABLED,1);
loadSetting(stmt, Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,"com.test.app/com.test.app.service.TestService");

. 在system app中动态添加

Settings.Secure.putString(getContentResolver(),Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,"com.test.app/com.test.app.service.TestService");Settings.Secure.putInt(getContentResolver(),Settings.Secure.ACCESSIBILITY_ENABLED, 1);

. 通过intent跳转到settings里面手动添加

Intent intent = new Intent(android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS);
startActivityForResult(intent, 0);

AccessibilityService 开启原理

Settings界面的初始话会获取所有已安装的apk的无障碍服务并列表展示出来



用户点击开启无障碍其实最终就是通过Setting secure写入对应的accessibility服务信息后通知AccessiBilityManagerService bind server，AccessiBilityManagerService 也是从Settings中读取对应的accessibility信息，所以想要使用accessibility网Settings secure写入服务信息是必须的。

@Override
142      public void onPreferenceToggled(String preferenceKey, boolean enabled) {
143          ComponentName toggledService = ComponentName.unflattenFromString(preferenceKey);
144          logAccessibilityServiceEnabled(toggledService, enabled);
145          if (!enabled) {
146              logDisabledState(toggledService.getPackageName());
147          }
148          AccessibilityUtils.setAccessibilityServiceState(getPrefContext(), toggledService, enabled);
149      }

关于默认开启无障碍服务的尝试
1 直接写入会报错

     Settings.Secure.putString(getContentResolver(),Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES, "com.fg/com.fg.test.TestAliveAccessibilityService");Settings.Secure.putString(getContentResolver(),Settings.Secure.ACCESSIBILITY_ENABLED, "1");Caused by: java.lang.SecurityException: Permission denial: writing to settings requires:android.permission.WRITE_SECURE_SETTINGS

2 通过权限申请的方式
可以申请成功但是依旧会permission denial
Permission denial: writing to settings requires:android.permission.WRITE_SECURE_SETTINGS
原因:在android 6.0及以后，WRITE_SETTINGS权限的保护等级已经由原来的dangerous升级为signature，这意味着我们的APP需要用系统签名或者成为系统预装软件才能够申请此权限，并且还需要提示用户跳转到修改系统的设置界面去授予此权限

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {if (!Settings.System.canWrite(MainActivity.this)) {Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS,Uri.parse("package:" + getPackageName()));intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);startActivityForResult(intent, 200);} else {Settings.Secure.putString(getContentResolver(),Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES, "com.fg/com.fg.test.TestAliveAccessibilityService");Settings.Secure.putString(getContentResolver(),Settings.Secure.ACCESSIBILITY_ENABLED, "1");}
}