58同城--内置图网络化方案探索与实践

//Resource#getDrawable，public Drawable getDrawable(@DrawableRes int id, @Nullable Theme theme)        throws NotFoundException {         if(图片是否需要网络化){             return 网络加载         } else {             //返回正常流程             return baseResources.getDrawable(id,  theme);         }}

class SkinTextView extend TextView {  public SkinTextView(Context context, @Nullable AttributeSet attrs) {          super(context, attrs);          setSkin(this,attrs);  }  private static final int[] ATTR_ARRAY = {         // 这个属性是系统类View的属性，对于APP领域是不可见的。         // 但是这个值是固定的，所以可以这样写，这里参考了RecycleView#NESTED_SCROLLING_ATTRS实现          16842964/* android.R.attr.background */,          android.R.attr.src  };
  public static void setSkin(View view, AttributeSet attrs, DraweeHolderSupplier supplier){
      Context context = view.getContext();      Resources resources = context.getResources();
      TypedArray ta = context.obtainStyledAttributes(attrs, ATTR_ARRAY);      Drawable background ;
      int drawableId ;      for (int i = 0; i < ATTR_ARRAY.length; i++) {          int attr = ATTR_ARRAY[i];          drawableId = ta.getResourceId(i,0);          if (drawableId == 0){              continue;          }          background = resources.getDrawable(drawableId,context.getTheme());          switch (attr) {              case 16842964:                  view.setBackground(background);                  break;              case android.R.attr.src:                  if (view instanceof ImageView) {                      ((ImageView)view).setImageDrawable(background);                  }                  break;          }      }      ta.recycle();  }}

// LayoutInflater#createViewFromTagView createViewFromTag(View parent, String name, Context context, AttributeSet attrs,        boolean ignoreThemeAttr) {    try {        View view;        if (mFactory2 != null) {            view = mFactory2.onCreateView(parent, name, context, attrs);        } else if (mFactory != null) {            view = mFactory.onCreateView(name, context, attrs);        } else {            view = null;        }
        if (view == null && mPrivateFactory != null) {            view = mPrivateFactory.onCreateView(parent, name, context, attrs);        }       // 以下onCreateView方法可以重载，拿到view对象强制触发getDrawable即可，中间需要一些过滤。讲一下大致思路，细节就不加了。        if (view == null) {            final Object lastContext = mConstructorArgs[0];            mConstructorArgs[0] = context;            try {                if (-1 == name.indexOf('.')) {                    view = onCreateView(parent, name, attrs);                } else {                    view = createView(name, null, attrs);                }            } finally {                mConstructorArgs[0] = lastContext;            }        }
        return view;    }}

/** * 自定义属性、View过滤 * Hook aapt打包过程，得到所有模块Res资源路径，遍历所有res/layout下的Xml */Pattern pattern = Pattern.compile("(?<=(android:(background|src)=\"@drawable/))([a-z_0-9]*)")void eachLayoutXml(File[] resDirs){    resDirs.each {        if (it.isDirectory() && it.name == "res") {            eachLayoutXml(it.listFiles())
        } else if (it.isDirectory() && it.name == "layout") {            it.listFiles().each { xml ->                // 获得xml内容，通过正则表达式匹配字符串            }        }    }}