Question

我正在尝试使用ViewPager从另一个片段“我的事件”（在导航抽屉中）实现两个片段（选项卡：相机，聊天）。这是ViewPager类，PagerViewAdapter.java：

package com.ercess.ercess_app;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

class PagerViewAdapter extends FragmentPagerAdapter {
    public PagerViewAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {

        Fragment fragment;

        switch (position){

            case 0:
                fragment = new Fragment_Camera();
                break;
            case 1:
                fragment = new Fragment_Chat();
                break;
            default:
                return null;
        }
        return fragment;
    }

    @Override
    public int getCount() {
        return 2;
    }
}

这是Java类，其中包含选项卡MyEventsFragment.java：

package com.ercess.ercess_app;

import android.content.Context;
import android.os.Build;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.view.LayoutInflater;
import android.support.annotation.Nullable;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;

import android.support.annotation.RequiresApi;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MyEventsFragment extends Fragment {
    TextView camera,chat;
    ViewPager viewPager;
    PagerViewAdapter pagerViewAdapter;
    Context context;

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

        camera = view.findViewById(R.id.camera);
        chat = view.findViewById(R.id.chat);
        viewPager = view.findViewById(R.id.fragment_container);

        pagerViewAdapter = new PagerViewAdapter(getFragmentManager());

        viewPager.setAdapter(pagerViewAdapter);

        camera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                viewPager.setCurrentItem(0);
            }
        });


        chat.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                viewPager.setCurrentItem(1);
            }
        });

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @RequiresApi(api = Build.VERSION_CODES.M)
            @Override
            public void onPageSelected(int position) {

                //position = 0;
                onChangeTab(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

        return view;
    }

    @RequiresApi(api = Build.VERSION_CODES.M)
    private void onChangeTab(int position) {

        if (position == 0)
        {
            camera.setTextSize(25);
            //camera.setTextColor(context.getColor(R.color.bright_color));

            chat.setTextSize(20);
            //chat.setTextColor(getColor(R.color.light_color));
            //camera.setTextColor(context.getColor(R.color.light_color));

        }

        if (position == 1)
        {
            camera.setTextSize(20);
            //camera.setTextColor(getColor(R.color.light_color));
            //camera.setTextColor(context.getColor(R.color.light_color));

            chat.setTextSize(25);
            //chat.setTextColor(getColor(R.color.bright_color));
            //camera.setTextColor(context.getColor(R.color.bright_color));

        }

    }
}

这是fragment_myevents.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<!--RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="My Event Fragment"
        android:textSize="30sp" />

</RelativeLayout-->

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg_color"
    tools:context=".MyEventsFragment">

    <include layout="@layout/tab_bar"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="52dp"/>

单击“我的事件”片段后，它将重定向到选项卡页面。照相机选项卡片段看起来应该像聊天选项卡片段一样，看起来不正确。尽管选项卡栏消失了，也可以从相机移到聊天选项卡。可以从相机滑动到聊天页面，但不能反向。

Android：ViewPager无法正常工作，没有错误

0 个答案: