场景：

1.统一设计Activity风格

2.加载外部资源，替换应用风格

3.不重启Activity的情况下，替换应用风格

4.应用使用系统默认View，开发者进行代码重构，想要增加view的功能，使用自定义View代替，却不想更改布局文件。例如：AppcomptActivity在factory使用新的View替换，实现风格的变换

原理：

1.拦截view创建

1.1创建自定义View

1.2穿件默认View，加载新的资源文件，设置View的属性

class SkinFactory implements LayoutInflater.Factory {private Context context;Resources resources;ArrayList<WeakReference<SkinAttr>> skinAttrs = new ArrayList<WeakReference<SkinAttr>>();public SkinFactory(Context context, Resources resources) {this.resources = resources;this.context = context;}@Overridepublic View onCreateView(String name, Context context, AttributeSet attrs) {
// 创建View-----------------------startView view = null;try {if (-1 == name.indexOf('.')) {if ("View".equals(name)) {view = LayoutInflater.from(context).createView(name,"android.view.", attrs);}if (view == null) {view = LayoutInflater.from(context).createView(name,"android.widget.", attrs);}if (view == null) {view = LayoutInflater.from(context).createView(name,"android.webkit.", attrs);}} else {view = LayoutInflater.from(context).createView(name, null,attrs);}} catch (Exception e) {e.printStackTrace();view = null;}
// 创建View-----------------------endif (view == null) {return null;}for (int i = 0; i < attrs.getAttributeCount(); i++) {String attributeName = attrs.getAttributeName(i);String attributeValue = attrs.getAttributeValue(i);TODO: 2/17/2017 find attr that can be change and set new attrif (resources != null)applyResource(resources, new SkinAttr(view, attributeName, attributeValue));}return view;}public void resotreDefault() {for (WeakReference<SkinAttr> skinAttrWeakReference : skinAttrs) {SkinAttr skinAttr = skinAttrWeakReference.get();if (skinAttr != null && skinAttr.getView() != null) {applyResource(context.getResources(), skinAttr);}}}public void applyResource(Resources resource,  SkinAttr skinAttr) {}class SkinAttr {View view;String attributeName;String attributeValue;public SkinAttr(View view, String attributeName, String attributeValue) {this.view = view;this.attributeName = attributeName;this.attributeValue = attributeValue;}public String getAttributeName() {return attributeName;}public View getView() {return view;}public String getAttributeValue() {return attributeValue;}public String getAttributeValueType() {return attributeValue.split("/")[0];}public String getAttributeValueName() {return attributeValue.split("/")[1];}}
}