在 Fragment 中找不到符号变量 R
cannot find symbol variable R in Fragment
public class home extends Fragment{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
postlist = (ListView)getView().findViewById(R.id.postList);
progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("Loading...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.show();
StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {
@Override
public void onResponse(String s) {
gson = new Gson();
list = (List) gson.fromJson(s, List.class);
postTitle = new String[list.size()];
for (int i = 0; i < list.size(); ++i) {
mapPost = (Map<String, Object>) list.get(i);
mapTitle = (Map<String, Object>) mapPost.get("title");
postTitle[i] = (String) mapTitle.get("rendered");
}
**postlist.setAdapter(new ArrayAdapter(getActivity(),android.R.layout.simple_list_item_1, postTitle));//R is not Resolved**
progressDialog.dismiss();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyerror) {
Toast.makeText(getActivity(),"Some error occurred", Toast.LENGTH_LONG).show();
}
});
return inflater.inflate(R.layout.home, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("Home");
}
}
我收到错误:找不到符号变量 R。如何解决它。
相同的代码 运行 在 activity 中很好,但在 activity 中使用时会出错。
试试这个在片段中绑定你的控件
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.home, container, false);
postlist = (ListView)rootView.findViewById(R.id.postList);
// your allll code
return rootView;
}
试试这个代码
View rootView
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (rootView != null) {
ViewGroup parent = (ViewGroup) rootView.getParent();
if (parent != null)
parent.removeView(rootView);
}
try {
rootView = inflater.inflate(R.layout.home, container, false);
} catch (InflateException e) {
}
return rootView;
}
我刚刚发生了同样的事情。
我尝试按照建议引用 rootView,但错误仍然存在。
我尝试了构建 -> 清理和重建,但错误仍然存在。
我最终删除了我的片段和相应的布局,然后通过android Studio界面重新创建了一个新的片段 (New=>Fragment=>Fragment(Blank)),并实现了与之前完全相同的代码,并且运行良好。
我知道,这不是您正在寻找的解决方案,但在花了太多时间尝试我在网上找到的所有建议后,这是对我有用的唯一方法。
在您的导入中检查 android.R 并将其删除。
Android Studio 在将 java 代码转换为 Kotlin 时有时会添加它。
public class home extends Fragment{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
postlist = (ListView)getView().findViewById(R.id.postList);
progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("Loading...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.show();
StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {
@Override
public void onResponse(String s) {
gson = new Gson();
list = (List) gson.fromJson(s, List.class);
postTitle = new String[list.size()];
for (int i = 0; i < list.size(); ++i) {
mapPost = (Map<String, Object>) list.get(i);
mapTitle = (Map<String, Object>) mapPost.get("title");
postTitle[i] = (String) mapTitle.get("rendered");
}
**postlist.setAdapter(new ArrayAdapter(getActivity(),android.R.layout.simple_list_item_1, postTitle));//R is not Resolved**
progressDialog.dismiss();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyerror) {
Toast.makeText(getActivity(),"Some error occurred", Toast.LENGTH_LONG).show();
}
});
return inflater.inflate(R.layout.home, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("Home");
}
}
我收到错误:找不到符号变量 R。如何解决它。 相同的代码 运行 在 activity 中很好,但在 activity 中使用时会出错。
试试这个在片段中绑定你的控件
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.home, container, false);
postlist = (ListView)rootView.findViewById(R.id.postList);
// your allll code
return rootView;
}
试试这个代码
View rootView
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (rootView != null) {
ViewGroup parent = (ViewGroup) rootView.getParent();
if (parent != null)
parent.removeView(rootView);
}
try {
rootView = inflater.inflate(R.layout.home, container, false);
} catch (InflateException e) {
}
return rootView;
}
我刚刚发生了同样的事情。
我尝试按照建议引用 rootView,但错误仍然存在。
我尝试了构建 -> 清理和重建,但错误仍然存在。
我最终删除了我的片段和相应的布局,然后通过android Studio界面重新创建了一个新的片段 (New=>Fragment=>Fragment(Blank)),并实现了与之前完全相同的代码,并且运行良好。
我知道,这不是您正在寻找的解决方案,但在花了太多时间尝试我在网上找到的所有建议后,这是对我有用的唯一方法。
在您的导入中检查 android.R 并将其删除。
Android Studio 在将 java 代码转换为 Kotlin 时有时会添加它。