1.先添加一下anko库
依赖:implementation "org.jetbrains.anko:anko:$anko_version"
版本:ext.anko_version='0.10.8'
2.新建Activity和Fragment的两个基类,方便以后使用
abstract class BaseActivity: AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(getLayoutId())
initData();
onListener();
}
abstract fun getLayoutId(): Int;//继承此类必须先实现此方法
protected open fun initData(){
}
protected open fun onListener() {
}
//
abstract class BaseFragment:Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
initData()
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return initView();
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
onListener()
}
abstract fun initView():View?
protected open fun initData(){
}
protected open fun onListener(){
}
}
3.底部导航
方案一:bottombar
依赖:implementation 'com.roughike:bottom-bar:2.3.1'
activity_main.xml改成LinearLayout布局,设置垂直布局
<FrameLayout
android:id="@+id/contentContainer"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1"/>
<com.roughike.bottombar.BottomBar
android:id="@+id/bottomBar"
android:layout_width="match_parent"
android:layout_height="56dp"
app:bb_tabXmlResource="@xml/bottombar_tabs"/>
新建xml Directory,添加bottombar_tabs.xml
<?xml version="1.0" encoding="utf-8"?>
<tabs>
<tab
id="@+id/tab_homepage"
icon="@drawable/homepage_icon"
title="主页" />
<tab
id="@+id/tab_favorites"
icon="@drawable/favorites_icon"
title="收藏" />
<tab
id="@+id/tab_message"
icon="@drawable/message_icon"
title="消息" />
<tab
id="@+id/tab_personal"
icon="@drawable/personal_icon"
title="我的" />
</tabs>
添加图标资源到drawable-xxhdpi目录中(不能直接添加到drawable中)
添加监听很简单
override fun initData() {
bottomBar.setOnTabSelectListener{
//it即是tab的id
// println(it)
}
接下来准备点击切换的四个fragment,都继承自BaseFragment,例如
class FavoritesFragment:BaseFragment() {
override fun initView(): View? {
var textView:TextView=TextView(activity) //getActivity()返回与之关联的activity
textView.text="收藏"
return textView
}
}
再准备一个管理fragment的类FragmentManage
class FragmentManage {
fun getFragment(tab_id:Int):BaseFragment?{
when(tab_id){
R.id.tab_homepage->return HomePageFragment()
R.id.tab_favorites->return FavoritesFragment()
R.id.tab_message->return MessageFragment()
R.id.tab_personal->return Personal()
}
return null
}
}
优化后的代码,创建单例模式,采用懒加载定义变量
class FragmentManage private constructor(){
val homePageFragmeng by lazy{HomePageFragment()}
val favoritesFragment by lazy{FavoritesFragment()}
val messageFragment by lazy{MessageFragment()}
val PersonalFragment by lazy{Personal()}
companion object{
val fragmentManage by lazy{
FragmentManage()
}
}
fun getFragment(tab_id:Int):BaseFragment?{
when(tab_id){
R.id.tab_homepage->return homePageFragmeng
R.id.tab_favorites->return favoritesFragment
R.id.tab_message->return messageFragment
R.id.tab_personal->return PersonalFragment
}
return null
}
}
这里可能找不到id,重启一下就可以了。R资源路径app\build\generated\not_namespaced_r_class_sources\debug\r\com\vocus\justtest
在MainActivity中设置对bottomBar的监听,并动态添加fragment
override fun initData() {
bottomBar.setOnTabSelectListener {
//it即是tab的id
// println(it)
val transAction = supportFragmentManager.beginTransaction()
//transAction.replace(R.id.contentContainer,FragmentManage().getFragment(it) as BaseFragment, it.toString())
transAction.replace(R.id.contentContainer,FragmentManage.fragmentManage.getFragment(it)!!,it.toString())
transAction.commit()
}
}
效果:
方案二:BottomNavigationView
null
4.主界面,设置HomePageFragment
设置状态栏背景透明
null
广告图片轮播(ViewPager)
设置homepagefragment布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.viewpager.widget.ViewPager
android:id="@+id/vp_homePageAd"
android:layout_width="match_parent"
android:layout_height="300dp">
</androidx.viewpager.widget.ViewPager>
<LinearLayout
android:id="@+id/dot_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_centerHorizontal="true"
android:layout_alignBottom="@+id/vp_homePageAd"
android:layout_marginBottom="10dp">
</LinearLayout>
</RelativeLayout>
新建HomePageAdAdapter类
class HomePageAdAdapter(): PagerAdapter(){
private val imageViewList=ArrayList<ImageView>()
constructor(imageViewList:ArrayList<ImageView>):this(){
this.imageViewList.addAll(imageViewList)
}
override fun isViewFromObject(view: View, `object`: Any): Boolean {
return view==`object`
}
override fun instantiateItem(container: ViewGroup, position: Int): Any {
// var textView= TextView(container.context)
// textView.text="test"
// container.addView(textView)
// return textView
container.addView(imageViewList.get(position))
return imageViewList.get(position)
}
override fun getCount(): Int {
return imageViewList.size
}
override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
container.removeView(`object` as View)
}
}
在HomePageFragment中添加代码
-
重写onListener方法(在onActivityCreated的声明周期里)
-
定义资源
/定义图片资源,一共五张
var imagesId=listOf(R.drawable.pic1,R.drawable.pic2,R.drawable.pic3,R.drawable.pic4,R.drawable.pic5)
//定义五个图片控件,用于加载图片资源
var imageViewList=ArrayList<ImageView>()
for(i in 0 until 5){
var imageView:ImageView=ImageView(activity)
imageView.setImageResource(imagesId[i])
imageViewList.add(imageView)
}
- 添加监听
// var vp_homePage:ViewPager=view!!.findViewById(R.id.vp_homePageAd)
// vp_homePage.adapter=HomePageAdAdapter()
vp_homePageAd.adapter=HomePageAdAdapter(imageViewList)
//
//添加页面改变监听
vp_homePageAd.addOnPageChangeListener(object :ViewPager.OnPageChangeListener{
override fun onPageScrollStateChanged(state: Int) {
}
//页面滚动的时候
override fun onPageScrolled(
position: Int,
positionOffset: Float,
positionOffsetPixels: Int
) {
}
override fun onPageSelected(position: Int) {
//添加圆点导航
addDots(position)
}
})
}
-
增加圆点导航方法
//偷懒的方法
fun addDots(position:Int){
dot_container.removeAllViews()
var dots=arrayOf<TextView>(TextView(activity),TextView(activity),TextView(activity),TextView(activity),TextView(activity))
dots.forEach {
it.text="."
it.setTextColor(Color.GRAY)
it.textSize=30f
}
for(i in 0 until 5) {
dot_container.addView(dots[i])
}
dots[position].setTextColor(Color.WHITE)
}
The specified child already has a parent. You must call removeView() on the child's parent first
我在把同一个TextView多次添加到布局中发生此错误,因为添加一次之后TextView就有parent了,直接在for循环中使用(textView.parent as ViewGroup?)!!.removeView(textView)也不行,因为循环的第二次会把第一次添加的移除。所以只能创建多个textview
错误代码为:
fun addDots(position:Int){
var dots=ArrayList<TextView>()
var textView=TextView(context)
textView.text="."
textView.setTextColor(Color.RED)
textView.textSize=30f
for(i in 0 until 5) {
if ((textView.parent as ViewGroup?) != null) {
(textView.parent as ViewGroup?)!!.removeView(textView)
}
dot_container.addView(textView)
}
}
继续完善
-
增加无限翻页
将getCount()返回值设置为Integer.MAX_VALUE,资源列表用到position取值的地方,要按5取模position%5,这样可以实现向后无限翻页;为了保证向前也能无限翻页,将PagerView的当前页设置为Integer.MAX_VALUE/2,同时-Integer.MAX_VALUE/2%5保证为5的倍数
vp_homePageAd.currentItem=Integer.MAX_VALUE/2-Integer.MAX_VALUE/2%5
-
循环播放
val handler: Handler =object:Handler(){
override fun handleMessage(msg: Message) {
super.handleMessage(msg)
vp_homePageAd.currentItem+=1
sendEmptyMessageDelayed(0,4000)
}
}
调用:handler.sendEmptyMessageDelayed(0,4000)
-
添加点击事件参考
vp_homePageAd.setOnTouchListener(object:View.OnTouchListener{ override fun onTouch(p0: View?, p1: MotionEvent?): Boolean { //Toast.makeText(context,"-x:${p1.x},y:${p1.y}",Toast.LENGTH_SHORT).show(); var flag:Int=0 when(p1!!.action){ MotionEvent.ACTION_DOWN->flag=0 //MotionEvent.ACTION_UP->flag=1 MotionEvent.ACTION_MOVE->flag=2 } println(flag.toString()) if(p1!!.action==MotionEvent.ACTION_UP&& flag==0){ val currentPage=vp_homePageAd.currentItem%5 when(currentPage+1){ 1->Toast.makeText(context,"1",Toast.LENGTH_SHORT).show() 2->Toast.makeText(context,"2",Toast.LENGTH_SHORT).show() 3->Toast.makeText(context,"3",Toast.LENGTH_SHORT).show() 4->Toast.makeText(context,"4",Toast.LENGTH_SHORT).show() 5->Toast.makeText(context,"5",Toast.LENGTH_SHORT).show() } } return false } })
(这个有问题。。。)
-
其他
·第一次进去程序没有圆点导航,需要初始化一下
·可以给每个页面添加文字说明
·用户按住某个页面时,应该停止轮播
效果
源码:
链接:https://pan.baidu.com/s/1NOoX2E7tV9js9QuNr-i5Hw
提取码:fwva