小编Jai*_*eph的帖子

我是 android 初学者，今天我创建了一个 BottomNavigationView 活动，我想显示 3 个不同的带有导航按钮的选项卡，所以我创建了 3 个片段，问题是添加片段后，BottomNavigationView 显示在顶部，如果我想要底部的底部导航视图就像在添加片段之前一样，我该怎么办，这里是我的主要活动代码

package com.hackerinside.jaisonjoseph.polysocial;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

private TextView mTextMessage;

public BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
        = new BottomNavigationView.OnNavigationItemSelectedListener() {

    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.navigation_home:

                tab1 radio = new tab1();
                android.support.v4.app.FragmentManager manager = getSupportFragmentManager();
                manager.beginTransaction().replace(R.id.container, radio, radio.getTag()).commit();


            case R.id.navigation_dashboard:


                tab2 radio1 = new tab2();
                android.support.v4.app.FragmentManager manager1 = getSupportFragmentManager();
                manager1.beginTransaction().replace(R.id.container, radio1, …

我正在创建一个选项卡式布局作为导航抽屉活动的主页片段，

所以我在主要活动中调用名为“test”的片段作为默认值。喜欢

        test home_fragment=new test();
        android.support.v4.app.FragmentManager manager=getSupportFragmentManager();
        manager.beginTransaction().replace(R.id.layout, home_fragment,home_fragment.getTag()).commit();

如果我再次调用这个片段。喜欢

if (id == R.id.nav_home) {


        test home_fragment=new test();
        android.support.v4.app.FragmentManager manager=getSupportFragmentManager();
        manager.beginTransaction().replace(R.id.layout, home_fragment,home_fragment.getTag()).commit();


    }

现在结果是 tab1 和 tab2 不见了

请参阅屏幕截图以获取更多参考

这是我的测试类（选项卡式布局）

 package com.hackerinside.jaisonjoseph.testapp;


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

 import static android.R.attr.x;


/**
 * A simple {@link Fragment} subclass.
*/
public class test extends Fragment {




public SectionsPagerAdapter mSectionsPagerAdapter;
public ViewPager mViewPager;





public test() {


}



@Override …

我想ProgressBar为我显示一个WebView,它应该在加载完成后停止,这是我的代码,但是当我调用ProgressBar它时显示无法解析方法findViewById

package com.fb.jaisonjoseph.facebookbasic;

import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;

/**
 * A simple {@link Fragment} subclass.
*/
 public class Home_Fragment extends Fragment {

public WebView mwebView;
public Home_Fragment() {

    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View rootView = inflater.inflate(R.layout.fragment_home_, null); …