Tablayout+ViewPager+Fragment的使用

xml

tab_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <!--TabLayout+ViewPager-->
    <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:ignore="MissingConstraints" />

    <android.support.v4.view.ViewPager
        android:id="@+id/main_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:ignore="MissingConstraints" />
</LinearLayout>

tab_sec.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tab_first"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv_head"
        android:layout_width="70dp"
        android:layout_height="70dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="25dp"
        android:background="@color/btn_filled_blue_bg_normal" />
    <!--输入框-->
    <EditText
        android:id="@+id/et_user_name"
        android:layout_width="fill_parent"
        android:layout_height="48dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginLeft="35dp"
        android:layout_marginTop="35dp"
        android:layout_marginRight="35dp"
        android:drawableLeft="@drawable/user"
        android:drawablePadding="10dp"
        android:gravity="center_vertical"
        android:hint="请输入用户名"
        android:paddingLeft="8dp"
        android:singleLine="true"
        android:textColor="#000000"
        android:textColorHint="#a3a3a3"
        android:textSize="14sp" />
    <!--输入框-->
    <EditText
        android:id="@+id/et_psw"
        android:layout_width="fill_parent"
        android:layout_height="48dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginLeft="35dp"
        android:layout_marginRight="35dp"
        android:drawableLeft="@drawable/pwd"
        android:drawablePadding="10dp"
        android:gravity="center_vertical"
        android:hint="请输入密码"
        android:inputType="textPassword"
        android:paddingLeft="8dp"
        android:singleLine="true"
        android:textColor="#000000"
        android:textColorHint="#a3a3a3"
        android:textSize="14sp" />
    <!--按钮-->
    <Button
        android:id="@+id/btn_login"
        android:layout_width="fill_parent"
        android:layout_height="40dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginLeft="35dp"
        android:layout_marginTop="15dp"
        android:layout_marginRight="35dp"
        android:text="登 录"
        android:textColor="@android:color/white"
        android:textSize="18sp" />
    <!--显示tv register , find_psw -->
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_marginLeft="35dp"
        android:layout_marginTop="8dp"
        android:layout_marginRight="35dp"
        android:gravity="center_horizontal"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/tv_register"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center_horizontal"
            android:padding="8dp"
            android:text="立即注册"
            android:textColor="@android:color/white"
            android:textSize="14sp" />
        <!--layout_weight="1" layout_width="0dp"实现均分效果-->
        <TextView
            android:id="@+id/tv_find_psw"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center_horizontal"
            android:padding="8dp"
            android:text="找回密码?"
            android:textColor="@android:color/white"
            android:textSize="14sp" />
    </LinearLayout>
</LinearLayout>

activity

LoginActivity.java

public class LoginActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
      //  隐藏标题栏
        if (getSupportActionBar() != null) {
            getSupportActionBar().hide();
        }
        setContentView(R.layout.tab_layout);
        TabLayout mTabLayout = findViewById(R.id.tab_layout);
        // 添加 tab item
        mTabLayout.addTab(mTabLayout.newTab().setText("注册"));
        mTabLayout.addTab(mTabLayout.newTab().setText("登录"));
        //设置adapter，滑动时间
        final ViewPager viewPager;
        viewPager = (ViewPager) findViewById(R.id.main_pager);
        viewPager.setAdapter(new PageAdapter(getSupportFragmentManager(), mTabLayout.getTabCount()));
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout));
        //绑定tab点击事件
        mTabLayout.setOnTabSelectedListener(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) {
            }
        });

PageAdapter.java

package com.example.tmftest;

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

import java.util.HashMap;

public class PageAdapter extends FragmentPagerAdapter {
    private int num;
    private HashMap<Integer, Fragment> mFragmentHashMap = new HashMap<>();

    public PageAdapter(FragmentManager fm, int num) {
        super(fm);
        this.num = num;
    }
    @Override
    public Fragment getItem(int position) {
        return createFragment(position);
    }
    @Override
    public int getCount() {
        return num;
    }
    private Fragment createFragment(int pos) {
        Fragment fragment = mFragmentHashMap.get(pos);
        if (fragment == null) {
            switch (pos) {
                case 0:
                    fragment = new Fragment1();
                    Log.i("fragment", "fragment1");
                    break;
                case 1:
                    fragment = new Fragment2();
                    Log.i("fragment", "fragment2");
                    break;
            }
            mFragmentHashMap.put(pos, fragment);
        }
        return fragment;
    }
}

Fragment2.java

public class Fragment2 extends android.support.v4.app.Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.tab_first,container,false);
        EditText editText1 = view.findViewById(R.id.et_user_name);
        Drawable drawable1 = getResources().getDrawable(R.drawable.user);
        drawable1.setBounds(0, 0, 60, 60);//第一0是距左边距离，第二0是距上边距离，60,60 分别是长宽
        editText1.setCompoundDrawables(drawable1, null, null, null);//只放左边

        EditText editText2 = view.findViewById(R.id.et_psw);
        Drawable drawable2 = getResources().getDrawable(R.drawable.pwd);
        drawable2.setBounds(0, 0, 60, 60);
        editText2.setCompoundDrawables(drawable2, null, null, null);

        return view;
    }
}