傳統的Android系統只有壹個framework-res.apk資源包，第三方廠商在進行rom定制時會直接修改framework res資源，達到美化目的。但是這種方式跟原生資源的耦合度過高，在系統遷移或者framework ui移植時需要進行人工merge，工作量巨大。通過為Android添加壹個新的獨立的資源包，可以將廠商定制資源獨立出來，可移植、可維護性非常好。
具體做法可以分為以下幾個步驟：
1. 修改build/core/clear_var.mk
LOCAL_USE_LETV_FRAMEWORK_RES:= true
2. 修改build/core/package.mk
以下腳本可以加在 $(R_file_stamp): $(framework_res_package_export_deps) 之前，然後修改$(R_file_stamp): $(framework_res_package_export_deps) 和 $(LOCAL_INTERMEDIATE_TARGETS): \
PRIVATE_AAPT_INCLUDES := $(framework_res_package_export)
如下所示：
view sourceprint?
1 ifeq ($(LOCAL_USE_LETV_FRAMEWORK_RES),true)
2 letv_framework_res_package_export := \
3 $(call intermediates-dir-for,APPS,letv-framework-res,,COMMON)/package-export.apk
4 letv_framework_res_package_export_deps := \
5 $(dir $(letv_framework_res_package_export))src/R.stamp
6 else
7 letv_framework_res_package_export :=
8 letv_framework_res_package_export_deps :=
9 endif # LOCAL_USE_LETV_FRAMEWORK_RES
view sourceprint?
1 $(R_file_stamp): $(framework_res_package_export_deps) $(letv_framework_res_package_export_deps)
2 $(LOCAL_INTERMEDIATE_TARGETS): \
3 PRIVATE_AAPT_INCLUDES := $(framework_res_package_export) \
4 $(letv_framework_res_package_export)
5 endif # LOCAL_NO_STANDARD_LIBRARIES
3. 修改build/target/product/core.mk
在PRODUCT_PACKAGES增加letv-framework-res
4. 添加壹個新的資源包項目，這裏在framework/base/core/res同級目錄下建立壹個新的文件夾letv_res用來存放我們的資源。把res目錄下的AndroidManifest.xml和Android.mk拷貝過來，進行修改。
記得設置LOCAL_USE_MY_FRAMEWORK_RES為false。
view sourceprint?
01 LOCAL_PATH:= $(call my-dir)
02 include $(CLEAR_VARS)
03
04 LOCAL_MODULE_TAGS := optional
05
06 LOCAL_PACKAGE_NAME := letv-framework-res
07 LOCAL_CERTIFICATE := platform
08
09 # Set LOCAL_USE_LETV_FRAMEWORK_RES as false
10 LOCAL_USE_LETV_FRAMEWORK_RES := false
11
12 # Tell aapt to create "extending (non-application)" resource IDs,
13 # since these resources will be used by many apps.
14 LOCAL_AAPT_FLAGS := -x
15
16 # Install this alongside the libraries.
17 LOCAL_MODULE_PATH := $(TARGET_OUT_JAVA_LIBRARIES)
18
19 # Create package-export.apk, which other packages can use to get
20 # PRODUCT-agnostic resource data like IDs and type definitions.
21 LOCAL_EXPORT_PACKAGE_RESOURCES := true
22
23 # Include resources generated by system RenderScript files.
24 framework_GENERATED_SOURCE_DIR := $(call intermediates-dir-for,JAVA_LIBRARIES,framework,,COMMON)/src
25 framework_RenderScript_STAMP_FILE := $(framework_GENERATED_SOURCE_DIR)/RenderScript.stamp
26 #LOCAL_RESOURCE_DIR := $(framework_GENERATED_SOURCE_DIR)/renderscript/res $(LOCAL_PATH)/res
27
28 include $(BUILD_PACKAGE)
29
30 # Make sure the system .rs files get compiled before building the package-export.apk.
31 #$(resource_export_package): $(framework_RenderScript_STAMP_FILE)
32
33 # define a global intermediate target that other module may depend on.
34 .PHONY: letv-framework-res-package-target
35 letv-framework-res-package-target: $(LOCAL_BUILT_MODULE)
view sourceprint?
01 <?xml version="1.0" encoding="utf-8"?>
02 <manifest xmlns:android=""
03 package="letv" coreApp="true" android:sharedUserId="android.uid.system"
04 android:sharedUserLabel="@null">
05
06 <application android:process="system"
07 android:persistent="true"
08 android:hasCode="false"
09 android:label="@null"
10 android:allowClearUserData="false"
11 android:killAfterRestore="false"
12 android:icon="@null">
13
14 </application>
15
16 </manifest>
資源的放置跟res下的類似，記得values目錄下創建public.xml，public.xml對id的類型區分比較嚴格，attr必須是0x0x010000開頭，drawable必須是0x0x020000開頭，其他類型好像就沒有限制，直接依次0x0x030000、0x0x040000開始即可。否則，編譯過程中會出現segmentation fault錯誤。
view sourceprint?
1 <resources>
2 <public type="attr" name="cForeground" id="0x03010000" />
3 <public type="drawable" name="ic_filemanager" id="0x03020000" />
4 <public type="style" name="LetvTheme" id="0x03030000" />
5 <public type="string" name="letv" id="0x03040000" />
6 <public type="dimen" name="letv_width" id="0x03050000" />
7 <public type="layout" name="letv_text" id="0x03060000" />
8 </resources>
5. 以上只是解決了資源的編譯環境問題，資源的查找過程也需要進行修改，修改 AssetManager.java，在init()後添加代碼 addAssetPath("/system/framework/letv-framework-res.apk");
view sourceprint?
01 public AssetManager() {
02 synchronized (this) {
03 if (DEBUG_REFS) {
04 mNumRefs = 0;
05 incRefsLocked(this.hashCode());
06 }
07 init();
08 addAssetPath("/system/framework/letv-framework-res.apk");
09 if (localLOGV) Log.v(TAG, "New asset manager: " + this);
10 ensureSystemAssets();
11 }
12 }
6. 最後就是資源應用問題。應用程序在xml文件中引用letv-framework-res.apk中的資源時可以使用與原生資源類似的訪問方式，首先聲明letv xmlns :
view sourceprint?
1 xmlns:letv=""
然後像@android:drawable @android:dimen這種引用方式改成@letv:drawable @letv:dimen即可。
view sourceprint?
01 <?xml version="1.0" encoding="utf-8"?>
02 <LinearLayout
03 xmlns:android=""
04 xmlns:letv=""
05 android:layout_width="fill_parent"
06 android:layout_height="wrap_content"
07 android:gravity="center"
08 android:paddingTop="@letv:dimen/letv_width"
09 android:orientation="horizontal" >
10
11 <ImageView android:id="@+id/file_icon"
12 android:layout_width="wrap_content"
13 android:layout_height="wrap_content"
14 android:layout_gravity="center"
15 android:layout_marginBottom="40dp"
16 android:src="@letv:drawable/ic_filemanager" />
17
18 </LinearLayout>
轉載，僅供參考。