Question

我遇到运行时错误：must implement OnFragmentInteractionListener

这是我的片段类文件，它呈现两个选项卡，tab1和tab2：

package com.ercess.ercess_app;

import android.net.Uri;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.support.annotation.Nullable;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.widget.TableLayout;

public class MyEventsFragment extends Fragment implements Tab1.OnFragmentInteractionListener,Tab2.OnFragmentInteractionListener{

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_myevents, container, false);

        TabLayout tabLayout = v.findViewById(R.id.tablayout);
        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
        //tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = v.findViewById(R.id.pager);
        final PagerAdapter adapter = new PagerAdapter(getFragmentManager(),tabLayout.getTabCount());
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });

        return v;
    }


    @Override
    public void onFragmentInteraction(Uri uri) {

    }
}

这是我要从片段中呈现的tab1的Java代码：

package com.ercess.ercess_app;

import android.net.Uri;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.support.annotation.Nullable;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.widget.TableLayout;

public class MyEventsFragment extends Fragment implements Tab1.OnFragmentInteractionListener,Tab2.OnFragmentInteractionListener{

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_myevents, container, false);

        TabLayout tabLayout = v.findViewById(R.id.tablayout);
        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
        //tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = v.findViewById(R.id.pager);
        final PagerAdapter adapter = new PagerAdapter(getFragmentManager(),tabLayout.getTabCount());
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });

        return v;
    }


    @Override
    public void onFragmentInteraction(Uri uri) {

    }
}

这是我的logcat：

09-11 18:05:15.231 6765-6765/? E/libprocessgroup: failed to make and chown /acct/uid_10060: Read-only file system
09-11 18:09:40.144 6765-6765/com.ercess.ercess_app **E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.ercess.ercess_app, PID: 6765
    java.lang.RuntimeException: com.ercess.ercess_app.Welcome@3c6aa0fb must implement OnFragmentInteractionListener
        at com.ercess.ercess_app.Tab1.onAttach(Tab1.java:83)**
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1404)
        at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1195)
        at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:1078)
        at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:117)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2408)
        at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
        at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2243)
        at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:654)
        at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:168)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1244)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1092)
        at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1622)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17547)
        at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1119)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
        at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
        at android.view.View.measure(View.java:17547)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1173)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1379)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootIm

Answer 1

我遇到了完全相同的问题，然后我发现出了什么问题。我忘记在创建选项卡之一时取消选中包括片段奇特的方法，并包括接口回调。您可能已经做过

Answer 2

实现接口时，必须覆盖接口中定义的功能，因此请检查Tab1类文件以找到功能签名并将其覆盖在MyEventsFragment文件中

或者您可以在alt + enter中的光标时按Tab1.OnFragmentInteractionListener,Tab2.OnFragmentInteractionListener，IDE（android studio）将提示您如何操作。

Answer 3

最好使您的呼叫活动实现这些接口。现在，EventsFragment是一个...片段。片段不应直接通信。

所有片段到片段的通信是通过共享完成的 ViewModel或通过关联的Activity。两个片段应该永远不要直接沟通。

更多信息：https://developer.android.com/training/basics/fragments/communicating

Android：错误：必须实现OnFragmentInteractionListener

3 个答案: