Android 中基于TabLayout+ViewPager实现标签卡效果

package com.plbear.yyj.myapplication
import android.os.Bundle
import android.support.design.widget.Snackbar
import android.support.design.widget.TabLayout
import android.support.v4.app.Fragment
import android.support.v4.app.FragmentPagerAdapter
import android.support.v7.app.AppCompatActivity
import android.view.Menu
import android.view.MenuItem
import kotlinx.android.synthetic.main.activity_main.*
class MainActivity : AppCompatActivity() {
  var mFragList = ArrayList()
  var adapter = object:FragmentPagerAdapter(supportFragmentManager){
    override fun getItem(position: Int): Fragment {
      return mFragList[position]
    }
    override fun getCount(): Int {
      return 2
    }
  }
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    initViewPager() //先将各个fragment加入到viewpager中
    initTabLayout(); //初始化tablayout
  }
  fun initTabLayout(){
    tab.setupWithViewPager(view_pager)
    tab.setTabsFromPagerAdapter(adapter)
    tab.tabMode = TabLayout.MODE_FIXED
    tab.getTabAt(0)?.setText("第一页")
    tab.getTabAt(1)?.setText("第二页")
  }
  fun initViewPager(){
    mFragList.add(Fragment1())
    mFragList.add(Fragment2())
    view_pager.adapter = adapter
  }
}