我开始学习 Android 并且在使用 fragment 时遇到了一些困难。你能帮我弄清楚问题是什么吗?除了下面提到的内容之外,其他所有内容在两个项目中都是相同的
1. Code without fragments (works totally fine. Gives a simple list with some data):
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerList);
LinearLayoutManager llm = new LinearLayoutManager(this);
llm.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(llm);
recyclerView.setAdapter(new MyRecyclerAdapter(generatePalettes()));
}
2. Code with Fragment (doesnt work. Blank Screen):
MainActivity
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new MainActivityFragment()).commit();
}
}
MainActivityFragment
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
RecyclerView recyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerList);
LinearLayoutManager llm = new LinearLayoutManager(getActivity());
llm.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(llm);
recyclerView.setAdapter(new PaletteAdapter(generatePalettes()));
return rootView;
}
--------------------------------更新------------ --
代码更改为以下内容:仍然不起作用。显示空白屏幕。尝试将 UI 更新放在 onActivityCreated 和 onViewCreated() 中。代码要点在这里:https://gist.github.com/adityarb88/12f5ccce665afbf58069
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.recyclerList);
LinearLayoutManager llm = new LinearLayoutManager(getActivity());
llm.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(llm);
recyclerView.setAdapter(new PaletteAdapter(generatePalettes()));
}
最佳答案
在构建 View 后,对于 Fragments 设置适配器:
主要 Activity fragment
此方法应该只膨胀并返回您的 View :
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
然后在onViewCreated(View, Bundle)
或onActivityCreated(Bundle)中:
@Override
public void onActivityCreated(Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
// getView() returns your Fragments root view
RecyclerView recyclerView = (RecyclerView) getView().findViewById(R.id.recyclerList);
LinearLayoutManager llm = new LinearLayoutManager(getActivity());
llm.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(llm);
recyclerView.setAdapter(new PaletteAdapter(generatePalettes()));
}
关于android - RecyclerView 在没有 fragment 的情况下工作。当我使用 fragment 时不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29528998/