Java 错误:必须实现OnFragmentInteractionListener
这是一个错误,说我必须实现OnFragmentInteractionListener,但就我所知,我正在正确地实现它。。。任何帮助都将不胜感激 主要活动Java 错误:必须实现OnFragmentInteractionListener,java,android,Java,Android,这是一个错误,说我必须实现OnFragmentInteractionListener,但就我所知,我正在正确地实现它。。。任何帮助都将不胜感激 主要活动 import android.app.Activity; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.os.Bundle; public class MainActivity extends Ac
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
public class MainActivity extends Activity implements NavFragment.OnFragmentInteractionListener, ContentFragment.OnFragmentInteractionListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.nav, new NavFragment());
fragmentTransaction.commit();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.content, new ContentFragment());
fragmentTransaction.commit();
}
@Override
public void onNavFragmentInteraction(String string) {
Bundle args = new Bundle();
args.putString("string", string);
ContentFragment content = new ContentFragment();
content.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
@Override
public void onContentFragmentInteraction(String string){
}
}
导航碎片
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
public class NavFragment extends Fragment implements View.OnClickListener {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private String mParam1;
private String mParam2;
private Button button;
private OnFragmentInteractionListener mListener;
public static NavFragment newInstance(String param1, String param2) {
NavFragment fragment = new NavFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public NavFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_nav, container, false);
button = (Button) v.findViewById(R.id.submit);
button.setOnClickListener(this);
return v;
}
public void onButtonPressed(String string) {
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
@Override
public void onClick(View v) {
String string = ((EditText) v.findViewById(R.id.gridSize)).toString();
mListener.onNavFragmentInteraction(string);
}
public interface OnFragmentInteractionListener {
public void onNavFragmentInteraction(String string);
}
}
内容片段
import android.app.Activity;
import android.app.Fragment;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.GridView;
public class ContentFragment extends Fragment {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public static ContentFragment newInstance(String param1, String param2) {
ContentFragment fragment = new ContentFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public ContentFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_content_fragmet, container, false);
String string = "1";
if (getArguments() != null) {
Bundle args = getArguments();
string = (String) args.get("string");
}
GridView gridView = (GridView) v.findViewById(R.id.gridview);
gridView.setNumColumns(Integer.parseInt(string));
gridView.setAdapter(new GridAdapter(this, Integer.parseInt(string)));
return v;
}
public void onButtonPressed(Uri uri) {
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
public void onContentFragmentInteraction(String string);
}
}
错误
两个s中的
OnFragmentInteractionListener
接口包含一个具有相同签名的方法,并且MainActivity
正在实现一个方法来尝试覆盖这两个接口
更改一个或两个方法的签名,然后在MainActivity
中实现这两个方法。例如:
NavFragment
public interface OnFragmentInteractionListener {
public void onNavFragmentInteraction(String string);
}
public interface OnFragmentInteractionListener {
public void onContentFragmentInteraction(String string);
}
ContentFragment
public interface OnFragmentInteractionListener {
public void onNavFragmentInteraction(String string);
}
public interface OnFragmentInteractionListener {
public void onContentFragmentInteraction(String string);
}
main活动
@Override
public void onNavFragmentInteraction(String string) {
// Do stuff
}
@Override
public void onContentFragmentInteraction(String string) {
// Do different stuff
}
因此,如果我想更简单地从ContentFragment中删除接口,然后删除ActivityMain中所述片段的暗示,这应该可以工作?几乎可以。您还必须删除
ContentFragment
的onAttach()
方法中需要Activity
来实现接口的部分。因此,我尝试创建两个不同的交互方法名称,并删除contentframgent(以及onAttach和onDetach中的部分),但它仍然给我这个错误请复制并粘贴整个错误在这里。还要注意的是,我用应该可以工作的示例代码更新了我的答案