TabLayout+ViewPager实现标签卡效果

转载请注明原文地址：http://www.cnblogs.com/yanyojun/p/8082391.html

代码已经上传至Github：https://github.com/YanYoJun/ViewPagerDemo

---

先看效果

1、布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context="com.plbear.yyj.myapplication.MainActivity">

    <android.support.design.widget.TabLayout
        android:id="@+id/tab"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        app:tabGravity="fill"
        app:tabIndicatorColor="#4978ef"
        app:tabIndicatorHeight="2dp"
        app:tabMode="scrollable"
        app:tabSelectedTextColor="#4978ef"
        app:tabTextColor="#222222"></android.support.design.widget.TabLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></android.support.v4.view.ViewPager>

</LinearLayout>

2、代码实现

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<Fragment>()
    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
    }

}

这里需要注意点，需要先将setupWithViewPager和tablayout绑定起来，然后再初始化tab的标签页，这个非常重要，否则会造成tablayout中的文字显示不出来。

这里注意，要保证support包和design包的版本号一致，不然app会出现闪退

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
    compile 'com.android.support:design:26.0.0-beta1'
    compile 'com.android.support:support-v4:26.0.0-beta1'
    implementation 'com.android.support:appcompat-v7:26.0.0-beta1'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:0.5'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:2.2.2'
}