MultipleItemRvAdapter 自定义BaseViewHolder出现强转异常的问题 #9

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1. K-Hector commented on Jul 10, 2018

   

   K-Hector

   on Jul 10, 2018

   Last edited by K-Hector

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   问题解决了，重写onCreateDefViewHolder(ViewGroup parent, int viewType)方法,，反射用的字节码对象应该拿BaseItemProvider上的

   @Override
   protected V onCreateDefViewHolder(ViewGroup parent, int viewType) {
       int layoutId = mLayoutResId;
       if (getMultiTypeDelegate() != null) {
           layoutId = getMultiTypeDelegate().getLayoutId(viewType);
       }
       View view = getItemView(layoutId, parent);
   
       Class temp = mItemProviders.get(viewType).getClass();
       Class z = null;
       while (z == null && null != temp) {
           z = getInstancedGenericKClass(temp);
           temp = temp.getSuperclass();
       }
       V k;
       // 泛型擦除会导致z为null
       if (z == null) {
           k = (V) new BaseViewHolder(view);
       } else {
           k = createGenericKInstance(z, view);
       }
       return k != null ? k : (V) new BaseViewHolder(view);
   }
   
   protected Class getInstancedGenericKClass(Class z) {
       Type type = z.getGenericSuperclass();
       if (type instanceof ParameterizedType) {
           Type[] types = ((ParameterizedType) type).getActualTypeArguments();
           for (Type temp : types) {
               if (temp instanceof Class) {
                   Class tempClass = (Class) temp;
                   if (BaseViewHolder.class.isAssignableFrom(tempClass)) {
                       return tempClass;
                   }
               } else if (temp instanceof ParameterizedType) {
                   Type rawType = ((ParameterizedType) temp).getRawType();
                   if (rawType instanceof Class && BaseViewHolder.class.isAssignableFrom((Class<?>) rawType)) {
                       return (Class<?>) rawType;
                   }
               }
           }
       }
       return null;
   }
   
   protected V createGenericKInstance(Class z, View view) {
       try {
           Constructor constructor;
           // inner and unstatic class
           if (z.isMemberClass() && !Modifier.isStatic(z.getModifiers())) {
               constructor = z.getDeclaredConstructor(getClass(), View.class);
               constructor.setAccessible(true);
               return (V) constructor.newInstance(this, view);
           } else {
               constructor = z.getDeclaredConstructor(View.class);
               constructor.setAccessible(true);
               return (V) constructor.newInstance(view);
           }
       } catch (NoSuchMethodException e) {
           e.printStackTrace();
       } catch (IllegalAccessException e) {
           e.printStackTrace();
       } catch (InstantiationException e) {
           e.printStackTrace();
       } catch (InvocationTargetException e) {
           e.printStackTrace();
       }
       return null;
   }