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

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:app="http://schemas.android.com/apk/res-auto"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     android:orientation="vertical"
 8     tools:context="com.plbear.yyj.myapplication.MainActivity">
 9 
10     <android.support.design.widget.TabLayout
11         android:id="@+id/tab"
12         android:layout_width="match_parent"
13         android:layout_height="40dp"
14         app:tabGravity="fill"
15         app:tabIndicatorColor="#4978ef"
16         app:tabIndicatorHeight="2dp"
17         app:tabMode="scrollable"
18         app:tabSelectedTextColor="#4978ef"
19         app:tabTextColor="#222222"></android.support.design.widget.TabLayout>
20 
21     <android.support.v4.view.ViewPager
22         android:id="@+id/view_pager"
23         android:layout_width="match_parent"
24         android:layout_height="wrap_content"></android.support.v4.view.ViewPager>
25 
26 </LinearLayout>

2、代码实现

 1 package com.plbear.yyj.myapplication
 2 
 3 import android.os.Bundle
 4 import android.support.design.widget.Snackbar
 5 import android.support.design.widget.TabLayout
 6 import android.support.v4.app.Fragment
 7 import android.support.v4.app.FragmentPagerAdapter
 8 import android.support.v7.app.AppCompatActivity
 9 import android.view.Menu
10 import android.view.MenuItem
11 
12 import kotlinx.android.synthetic.main.activity_main.*
13 
14 class MainActivity : AppCompatActivity() {
15 
16     var mFragList = ArrayList<Fragment>()
17     var adapter = object:FragmentPagerAdapter(supportFragmentManager){
18         override fun getItem(position: Int): Fragment {
19             return mFragList[position]
20         }
21 
22         override fun getCount(): Int {
23             return 2
24         }
25     }
26 
27     override fun onCreate(savedInstanceState: Bundle?) {
28         super.onCreate(savedInstanceState)
29         setContentView(R.layout.activity_main)
30         initViewPager() //先将各个fragment加入到viewpager中
31         initTabLayout(); //初始化tablayout
32     }
33 
34 
35     fun initTabLayout(){
36         tab.setupWithViewPager(view_pager)
37         tab.setTabsFromPagerAdapter(adapter)
38         tab.tabMode = TabLayout.MODE_FIXED
39         tab.getTabAt(0)?.setText("第一页")
40         tab.getTabAt(1)?.setText("第二页")
41     }
42 
43     fun initViewPager(){
44         mFragList.add(Fragment1())
45         mFragList.add(Fragment2())
46 
47         view_pager.adapter = adapter
48     }
49 
50 }

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'
}