基于Android-Skin-Loader的换肤效果

skin-loader框架的换肤是通过插件化的形式替换资源文件，实现换肤效果。好处是可以在线更新皮肤换肤
android-skin-loader源码

Demo样例

流程

整个框架大概的流程是加载皮肤包，找到被标记的控件，通过自定义的Factory工程过滤掉其他控件，使用皮肤包中的资源文件更新被标记的ui。

使用操作

1. 导入android-skin-loader框架包
   androidStudio File->new->import Module选择android-skin-loader
   项目右键->open Module Setting->app中加载依赖android-skin-loader库

2. 在MyApplication 初始化框架

    SkinManager.getInstance().init(this);
    SkinManager.getInstance().load();

3. 需要换肤的activity需要继承skin-loader中的BaseActivity
   需要换肤的控件添加skin:enable=”true”，控件xml添加命名空间xmlns:skin=”http://schemas.android.com/android/skin”

4. 准备需要替换的color或drawable同名的资源文件包将其打包，重命名以.skin结尾
   本地测试可以使用adb命令将.skin包放在sdcard
   adb push 文件目录/test.skin /sdcard

   样例代码

xml文件，使用databinding，不知道的自行百度

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:skin="http://schemas.android.com/android/skin">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
            <Button
                android:id="@+id/btn_default"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="@color/text_color"
                android:background="@color/button_background"
                skin:enable="true"
                android:text="默认皮肤"/>
            <Button
                android:id="@+id/btn_change_skin"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:textColor="@color/text_color"
                android:background="@color/button_background"
                skin:enable="true"
                android:text="更改皮肤"/>
            <Button
                android:id="@+id/btn_add"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:textColor="@color/text_color"
                android:background="@color/button_background"
                skin:enable="true"
                android:text="动态添加布局"/>
        LinearLayout>
       <TextView
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:textColor="@color/text_color"
           android:text="文字文字文字文字文字文字"
           skin:enable="true" />
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/skin"
            skin:enable="true"/>
        <LinearLayout
            android:id="@+id/add_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            skin:enable="true"
            android:orientation="vertical">
        LinearLayout>

    LinearLayout>
layout>

public class SkinChangeAct extends BaseActivity{
    private ActivitySkinchangeBinding binding;
    //skin包名
    private String SKIN_NAME = "test.skin";
    //skin皮肤包的路径
    private String SKIN_DIR = Environment.getExternalStorageDirectory()+ File.separator+SKIN_NAME;
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_skinchange);
        //更换皮肤
        binding.btnChangeSkin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                File skin = new File(SKIN_DIR);
                if(skin == null || !skin.exists()){
                    Toast.makeText(getApplicationContext(), "请检查" + SKIN_DIR + "是否存在", Toast.LENGTH_SHORT).show();
                    return;
                }

                SkinManager.getInstance().load(skin.getAbsolutePath(), new ILoaderListener() {
                    @Override
                    public void onStart() {
                        System.out.println("start");
                    }

                    @Override
                    public void onSuccess() {
                        System.out.println("onSuccess");
                    }

                    @Override
                    public void onFailed() {
                        System.out.println("onFailed");
                    }
                });
            }
        });
        //恢复默认皮肤
        binding.btnDefault.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                SkinManager.getInstance().restoreDefaultTheme();
            }
        });
        //动态加载控件
        binding.btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                dynamicAddTextView();
            }
        });
    }
    /**动态添加textview*/
    private void dynamicAddTextView() {
        TextView                    textView = new TextView(this);
        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,   ViewGroup.LayoutParams.WRAP_CONTENT);
        params.addRule(RelativeLayout.CENTER_IN_PARENT);
        textView.setLayoutParams(params);
        textView.setTextColor(SkinManager.getInstance().getColor(R.color.text_color));
        textView.setText("hellohello");
        textView.setTextSize(28);
        //将动态添加的布局也更换皮肤，否则之前添加的不能更改
        List mDanamicAttr = new ArrayList();
        mDanamicAttr.add(new DynamicAttr(AttrFactory.TEXT_COLOR,R.color.text_color));
        dynamicAddView(textView,mDanamicAttr);
        binding.addLayout.addView(textView);
    }
}

资源文件color.xml

<resources>
    <color name="colorPrimary">#3F51B5color>
    <color name="colorPrimaryDark">#303F9Fcolor>
    <color name="colorAccent">#FF4081color>
    <color name="text_color">#ff0000color>
    <color name="button_background">#00ff00color>
resources>

skin皮肤包中的资源文件color.xml

<resources>
    <color name="colorPrimary">#3F51B5color>
    <color name="colorPrimaryDark">#303F9Fcolor>
    <color name="colorAccent">#FF4081color>
    <color name="text_color">#ffff00color>
    <color name="button_background">#00ffffcolor>
resources>

对比一下，只是更改了数值，名字相同。

框架迭代，增加功能

android-skin-loader框架是没有对于src属性的修改，案例中使用imageView模拟了src的更改。
在AttrFactory中增加对于src的支持

public class AttrFactory {

    public static final String BACKGROUND = "background";
    public static final String TEXT_COLOR = "textColor";
    public static final String LIST_SELECTOR = "listSelector";
    public static final String DIVIDER = "divider";
    //增加src属性
    public static final String SRC="src";

    public static SkinAttr get(String attrName, int attrValueRefId, String attrValueRefName, String typeName){

        SkinAttr mSkinAttr = null;
        System.out.println("attrName="+attrName);
        if(BACKGROUND.equals(attrName)){ 
            mSkinAttr = new BackgroundAttr();
        }else if(TEXT_COLOR.equals(attrName)){ 
            mSkinAttr = new TextColorAttr();
        }else if(LIST_SELECTOR.equals(attrName)){ 
            mSkinAttr = new ListSelectorAttr();
        }else if(DIVIDER.equals(attrName)){ 
            mSkinAttr = new DividerAttr();
        }else if(SRC.equals(attrName)){
            //自定义加载src
            mSkinAttr =new SrcAttr();
        }else{
            return null;
        }

        mSkinAttr.attrName = attrName;
        mSkinAttr.attrValueRefId = attrValueRefId;
        mSkinAttr.attrValueRefName = attrValueRefName;
        mSkinAttr.attrValueTypeName = typeName;
        return mSkinAttr;
    }

    /**
     * Check whether the attribute is supported
     * @param attrName
     * @return true : supported 

     *         false: not supported
     */
    public static boolean isSupportedAttr(String attrName){
        if(BACKGROUND.equals(attrName)){ 
            return true;
        }
        if(TEXT_COLOR.equals(attrName)){ 
            return true;
        }
        if(LIST_SELECTOR.equals(attrName)){ 
            return true;
        }
        if(DIVIDER.equals(attrName)){ 
            return true;
        }
        //支持src
        if(SRC.equals(attrName)){
            return true;
        }
        return false;
    }
}

srcAttr继承SkinAttr定义加载src

public class SrcAttr extends SkinAttr{
    @Override
    public void apply(View view) {
        if(view instanceof ImageView){
            ImageView imageView = (ImageView) view;
            if(RES_TYPE_NAME_COLOR.equals(attrValueTypeName)){
              imageView.setImageResource(SkinManager.getInstance().getColor(attrValueRefId));
            }else if(RES_TYPE_NAME_DRAWABLE.equals(attrValueTypeName)){
                Drawable bg = SkinManager.getInstance().getDrawable(attrValueRefId);
                imageView.setImageDrawable(bg);
            }
        }
    }
}

各种控件的支持都可以自己添加。