关于tablayout向上滑动停留页面顶部（有待完善）
activity_main布局:
注：在使用AppBarLayout控件时需要导design包
implementation'com.android.support:design:27.+'
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:fitsSystemWindows="true" tools:context=".MainActivity"> android:id="@+id/app_bar" android:layout_width="match_parent" android:layout_height="wrap_content" android:fitsSystemWindows="true"> android:id="@+id/toolbar_layout" android:layout_width="match_parent" android:layout_height="250dp" android:fitsSystemWindows="true" app:contentScrim="?attr/colorPrimary" app:layout_scrollFlags="scroll|exitUntilCollapsed"> android:layout_width="match_parent" android:layout_height="match_parent" android:background="@mipmap/happyxueche"/> android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" app:layout_collapseMode="pin" app:title="Toolbar"/> android:id="@+id/tabLayout" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" app:tabIndicatorColor="#FFFFFFFF" app:tabSelectedTextColor="#FF888888" app:tabTextColor="#FFFFFFFF"/> android:id="@+id/nestedScrollView" android:layout_width="match_parent" android:layout_height="match_parent" android:fillViewport="true" app:layout_behavior="@string/appbar_scrolling_view_behavior"> android:id="@+id/viewPager" android:layout_width="match_parent" android:layout_height="wrap_content"/>
mainActivity中：
package com.example.lijunlu.image724;
import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import com.example.lijunlu.image724.adapter.ResumeAdapter;
public class MainActivityextends AppCompatActivity {
private Toolbartoolbar;
private CollapsingToolbarLayouttoolbar_layout;
private TabLayouttabLayout;
private AppBarLayoutapp_bar;
private NestedScrollViewnestedScrollView;
private ViewPagerviewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//设置返回主页的按钮getSupportActionBar().setDisplayHomeAsUpEnabled(true);
toolbar_layout = (CollapsingToolbarLayout) findViewById(R.id.toolbar_layout);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
app_bar = (AppBarLayout) findViewById(R.id.app_bar);
nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);
viewPager = findViewById(R.id.viewPager);
nestedScrollView.setFillViewport(true);
ResumeAdapter rusumeAdapter =new ResumeAdapter(getSupportFragmentManager());
viewPager.setAdapter(rusumeAdapter);
tabLayout.setupWithViewPager(viewPager);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
nestedScrollView.scrollTo(0,0);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
}
适配器：
package com.example.lijunlu.image724.adapter;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import com.example.lijunlu.image724.AFragment;
import com.example.lijunlu.image724.BFragment;
import com.example.lijunlu.image724.CFragment;
import com.example.lijunlu.image724.DFragment;
public class ResumeAdapterextends FragmentPagerAdapter{
public ResumeAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment fragment =null;
if (0 == position) {
fragment =new AFragment();
}else if (1 == position) {
fragment =new BFragment();
}else if (2 == position) {
fragment =new CFragment();
}else if (3 == position) {
fragment =new DFragment();
}
return fragment;
}
@Override
public int getCount() {
return 4;
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "头条";
case 1:
return "热点";
case 2:
return "娱乐";
case 3:
return "体育";
}
return null;
}
}