当问题出现的时候不光要解决还要知道为什么
看一下源码:
void dispatchLayout() { if (mAdapter == null) { Log.e(TAG, "No adapter attached; skipping layout"); // leave the state in START return; } if (mLayout == null) { Log.e(TAG, "No layout manager attached; skipping layout"); // leave the state in START return; } .... }
当Adapter和LayoutManager 都没有的时候,就会抛出No … attached; skipping layout 异常
众所周知,RecyclerView的出现不光可以代替ListView,也可以代替GridView,所以啊大胸弟,你在用的时候要告诉RecyclerView你要代替的是哪个啊,就是所谓的初始化配置,不配置就会警告报错、不显示数据
分割线可以不设置,动画也可以不设置,但是LayoutManager必须设置。
随意示范一下
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false); mRecyclerView.setLayoutManager(linearLayoutManager);
上面用的是LinearLayoutManager的第二个构造方法,必要的参数都有了,当然也可以用第一个构造,贴一下这个构造的代码:
/** * @param context Current context, will be used to access resources. * @param orientation Layout orientation. Should be {@link #HORIZONTAL} or {@link * #VERTICAL}. * @param reverseLayout When set to true, layouts from end to start. */ public LinearLayoutManager(Context context, int orientation, boolean reverseLayout) { setOrientation(orientation); setReverseLayout(reverseLayout); setAutoMeasureEnabled(true); }
或者 简单版,默认 VERTICAL
mRecyclerView.setLayoutManager(new LinearLayoutManager(mContext));
/** * Creates a vertical LinearLayoutManager * * @param context Current context, will be used to access resources. */ public LinearLayoutManager(Context context) { this(context, VERTICAL, false); }
当然,不要忘了 mRecyclerView.setAdapter(mAdapter);
几种LayoutManager
LinearLayoutManager 线性布局管理器
GridLayoutManager 表格布局管理器
StaggeredGridLayoutManager 瀑布流布局管理器