如何在api层屏蔽系统的一些功能特性

以屏蔽系统的FEATURE_PRINTING功能为例，可以通过如下修改，使得系统对app屏蔽了打印机功能

1、frameworks/base/core/java/com/android/server/SystemConfig.java

加载完所有的xml文件后，将FEATURE_PRINTING特性去除

--- a/core/java/com/android/server/SystemConfig.java
+++ b/core/java/com/android/server/SystemConfig.java
@@ -403,6 +403,8 @@ public class SystemConfig {
         Environment.getProductServicesDirectory(), "etc", "sysconfig"), ALLOW_ALL);
     readPermissions(Environment.buildPath(
         Environment.getProductServicesDirectory(), "etc", "permissions"), ALLOW_ALL);
+
+        removeFeature(PackageManager.FEATURE_PRINTING);
   }

2、在配置文件device/sprd/board/common/handheld_core_hardware.xml 去除将FEATURE_PRINTING特性去除

去除