Packages T□pp com.example.android.lifecycle P回tet 白u R.java ActivityA ©Activity8 ©a ActivityC BuildConfig ©DialogActivity ER R.java:hook the resources and java by P▣drawable--hdpi ▣drawable-ldpi P▣drawable-mdpi providing each resource item an ID 回drawable-xhdpi P▣layout y回values Reference a resource in Java codes Libraries [<package_name>.]R.<resource_type>.<resource_name> o <package_name>:name of the package in which the resource is located (not required when referencing resources from your own package). o <resource_type>:resource type. o <resource_name>:the resource filename without the extension or the android:name attribute value in the XML element. findViewById(R.id.***)identify a view on XML by its id ● setContentView(R.layout.***)apply the layout for the content view 0 • Reference a resource in Java codes o <package_name>: name of the package in which the resource is located (not required when referencing resources from your own package). o <resource_type>: resource type. o <resource_name>: the resource filename without the extension or the android:name attribute value in the XML element. R.java • R.java: hook the resources and java by providing each resource item an ID 10 [<package_name>.]R.<resource_type>.<resource_name> • findViewById(R.id.***): identify a view on XML by its id • setContentView(R.layout.***): apply the layout for the content view