关于Android新语言Kotlin初识

#关于Android新语言Kotlin初识

2017年5月的IO大会上,Google宣布,kotlin成为开发Android的一级编程语言.

Kotlin不仅可以再JVM上运行,还可以直接将Kotlin源代码转换成JavaScript,理论上将,kotlin可以在任何支持JavaScript的环境中运行,例如WEB应用,reactNatice(Android和IOS),微信公众号,微信小程序,Node.js等,另外,还有一些地方是JavaScript做不到的,如开发本地应用,但kotlin可以做到,kotlin不仅仅可以生成JavaScript代码,还可以直接编译成本地代码,如Windows的exe文件,iOS APP等,这样一来,kotlin几乎和可以开发所有类型的应用.

---

##kotlin的优势:

• 容易学习

  kotlin是一门包含很多函数式编程思想的面相对象编程语言

• 轻量级

  相比其他编程语言,kotlin的函数库更小,小于7000个

• 高度可互操作性:

  kotlin可以和其他java类库友好且简单的进行互操作

• 继承Androidstudio及gradle

  专门的插件,和工具

• 其他语法层面的特性,如数据模型类,空类型安全,扩展函数等

kotlin能做什么

• 服务端开发

  kotlin是基于JVM的编程语言,自然可以使用所有基于JVM的服务端框架 例如:spring

• 以JavaScript方式运行

  kotlin提供了生成JavaScript源代码的能力

• 开发Android App

  kotlin和java源代码可以在同一个工程中,可以联合进行调试

##kotlin的基本语法

• 定义变量

  // 定义变量
  var m: Int? = 0
  // 自动推导变量的数据类型
  var n = 10
  // 定义常量
  val f = 30
  // 定义数组
  var arr1 = arrayOf(1, 2, 3, 4)
  var arr3: IntArray? = null
  // 定义集合
  var list1 = arrayListOf<String>()
  var list2: ArrayList<String>? = null
  // 定义字符串
  var s1 = "Hello \nworld"
  var s2: String = "世界\n 你好"
  var s3 = """
          hello
              world
                  I love you.
  """
  

• 定义方法

  // 定义普通方法
  fun test() {
  
  }
  
  // 定义带返回值方法
  fun test1(): String {
      return "返回值"
  }
  

• get,set方法

  var address: String = ""
      get() {
          println("get Method is run")
          return if (field.contains("北京市")) {
              field.replace("北京市", "许昌市")
          } else {
              field
          }
  
      }
      set(value) {
          println("setMethod is run")
          field = value
      }
  
  

• 定义构造器

  // 一级构造器
  class KotlinBean constructor() {
  
  }
  // 二级构造器
  class KotlinBean constructor() {
      constructor(index: Int) : this()
  }
  

• 数值类型

数据类型	占用字节数
Double	8
Float	4
Long	8
Int	4
Short	2
Byte	1

• 字符串模板

   // 字符串模板 添加占位符 $
      override fun toString(): String {
          return "KotlinBean(m=$m, n=$n, f=$f, arr1=${Arrays.toString(arr1)}, arr3=${Arrays.toString(arr3)}, list1=$list1, list2=$list2)"
      }
  
  

• if语句

    // 定义带返回值方法
  fun test1(): String {
      return if (n > 10) {
          "ssss"
      } else {
          "返回值"
      }
  }
  

• when语句(替代原来的switch语句)

    rg_navigation.setOnCheckedChangeListener { group, checkedId ->
          when (checkedId) {
              R.id.rb_home -> {
                  switchTab(0)
              }
              R.id.rb_mirror -> {
                  switchTab(1)
              }
              R.id.rb_bbs -> {
                  switchTab(2)
              }
              R.id.rb_mine -> {
                  switchTab(3)
              }
  
          }
      }
      
         fun test2(n: Int) {
      when (n) {
          1 -> {
          }
          2 -> {
          }
          // 使用in关键字
          in 3..5 -> {
  
          }
          // 使用函数表达式的返回值
          test3() -> {
              
          }
          else -> {
  
          }
      }
  
  }
  

• for循环

  fun test4() {
      // 强循环,直接遍历
      list1.forEach { t: String? -> println(t) }
      for (s: String in list1) {
          println(s)
      }
      // 根据角标遍历
      for (i in list1.indices) {
          println(list1[i])
      }
      // 根据角标遍历,同时获取角标和对应的元素值
      for ((index, value) in list1.withIndex()) {
          println(index)
          println(value)
      }
  }
  

• 修饰符

  1. private 仅在类的内部可以访问
  2. protected 类似private,但在子类中也可以访问
  3. internal 任何在模块内部类都可以访问
  4. public 任何类都可以访问

• 类的继承

  与Java不同,kotlin类的继承需要使用冒号(:),冒号后面需要调用父类的构造器

  需要注意的是kotlin默认是的class是final的,也就是说默认class不允许继承,需要显示的使用open关键字允许继承class

  open class KotlinBean constructor() {
  
  constructor(index: Int) : this()
  
  }
  
  

• 重写方法 & 重写属性

  在kotlin中,不仅类默认是不可继承的,连方法默认也是不可重写的.因此,如果要在子类中重写方法,就需要在父类相应的方法前面加open关键字,而且要在子类重写的方法前面加override关键字

• 接口

  kotlin中的接口与Java中的类似,使用interface关键字声明.一个类可以实现多个接口,并且接口中的属性和方法都是open的

  interface KotlinInterfaceTest {
  fun getUserInfo()
      // 在kotlin中,允许接口的方法包含默认的方法体
  fun setUserInfo(name: String) {
      val userBean = UserBean()
      userBean.name = name
  }
  

}

• null 值安全性

  在java中饱受null异常的困扰,在kotlin中可以试图解决这个问题

  kotlin中导致NPE情况

  1. 明确调用throw NullPointerException()
  2. 使用!! 操作符
  3. 外部的Java代码导致
  4. 初始化过程中存在某些数据不一致

• 开始使用kotlin进行Android开发

  1. 创建一个应用

     勾选kotlin选项,点击Next,知道项目创建完成

  

  

  

  2. 编写XML文件

  

  3. 在activity中设置UI显示

  

• 其他示例

  class HomeFragment @SuppressLint("ValidFragment")
  private constructor() : Fragment() {
      var value: HomeFragment? = null
      var imageList = arrayListOf<Int>()
      lateinit var mContext: Context
      lateinit var mHomeAdapter: HomeAdapter
  
      private object Holder {
          val INSTANCE = HomeFragment()
      }
  
      companion object Factory {
          fun getInstance(): HomeFragment {
              return Holder.INSTANCE
          }
  
      }
  
      override fun onAttach(context: Context?) {
          super.onAttach(context)
          mContext = context!!
      }
  
      override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
  
  
          return inflater!!.inflate(R.layout.fragment_home, container, false)
      }
  
      override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
          super.onViewCreated(view, savedInstanceState)
          initView()
          initData()
      }
  
      private fun initView() {
          banner.setImageLoader(GlideImageLoader())
          imageList.add(R.mipmap.ic_driver)
          imageList.add(R.mipmap.ic_police)
          imageList.add(R.mipmap.ic_trance)
          banner.setImages(imageList).start()
          rv_top_lines.setHasFixedSize(true)
          rv_top_lines.layoutManager = LinearLayoutManager(mContext)
      }
  
      class MyLinear2(context: Context?) : LinearLayoutManager(context) {
          override fun canScrollVertically(): Boolean {
              return false
          }
  
      }
  
      private fun initData() {
          mHomeAdapter = HomeAdapter()
          rv_top_lines.adapter = mHomeAdapter
  
          HttpManager.getInstance().getRetrofit().create(IApiServices::class.java).getHostList()
                  .subscribeOn(Schedulers.io())
                  .observeOn(AndroidSchedulers.mainThread())
                  .doOnNext { t: BaseBean<List<MovieBean>>? ->
                      if (t != null) {
                          val data = t.data
                          data.forEach { t -> println(t.toString()) }
                      }
                  }.subscribe(object : Observer<BaseBean<List<MovieBean>>> {
              override fun onSubscribe(d: Disposable) {
                  println("onSubscribe")
              }
  
              override fun onError(e: Throwable) {
                  println("onError" + e.message)
                  Toast.makeText(mContext, e.message, Toast.LENGTH_SHORT).show()
              }
  
              override fun onNext(t: BaseBean<List<MovieBean>>) {
                  println("onNext" + t.toString())
                  mHomeAdapter.setNewData(t.data)
              }
  
              override fun onComplete() {
                  println("onComplete")
                  Toast.makeText(mContext, "onComplete", Toast.LENGTH_SHORT).show()
  
              }
          })
      }
  
      override fun onStart() {
          super.onStart()
          //开始轮播
          banner.startAutoPlay()
      }
  
      override fun onStop() {
          super.onStop()
          //结束轮播
          banner.stopAutoPlay()
      }
  }
  

---

• home页tab切换

  package com.bidostar.kotlindemo.activity
  
  import android.os.Bundle
  import android.support.v7.app.AppCompatActivity
  import com.bidostar.kotlindemo.R
  import com.bidostar.kotlindemo.fragment.BbsFragment
  import com.bidostar.kotlindemo.fragment.HomeFragment
  import com.bidostar.kotlindemo.fragment.MineFragment
  import com.bidostar.kotlindemo.fragment.MirrorFragment
  import kotlinx.android.synthetic.main.activity_home.*
  
  class HomeActivity : AppCompatActivity() {
      //  1. lateinit 延迟加载
      //  2.lateinit 只能修饰, 非kotlin基本类型
      lateinit var mHomeFragment: HomeFragment
      lateinit var mMirrorFragment: MirrorFragment
      lateinit var mBbsFragment: BbsFragment
      lateinit var mMineFragment: MineFragment
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.activity_home)
          initView()
          val transaction = supportFragmentManager.beginTransaction()
          transaction.add(R.id.fl_content, mHomeFragment, "home")
          transaction.add(R.id.fl_content, mMirrorFragment, "mirror")
          transaction.add(R.id.fl_content, mBbsFragment, "bbs")
          transaction.add(R.id.fl_content, mMineFragment, "mine")
          transaction.commitAllowingStateLoss()
  
          rg_navigation.setOnCheckedChangeListener { group, checkedId ->
              when (checkedId) {
                  R.id.rb_home -> {
                      switchTab(0)
                  }
                  R.id.rb_mirror -> {
                      switchTab(1)
                  }
                  R.id.rb_bbs -> {
                      switchTab(2)
                  }
                  R.id.rb_mine -> {
                      switchTab(3)
                  }
  
              }
          }
          switchTab(0)
  
      }
  
      private fun initView() {
          mHomeFragment = HomeFragment.getInstance()
          mMirrorFragment = MirrorFragment.getInstance()
          mBbsFragment = BbsFragment.getInstance()
          mMineFragment = MineFragment.getInstance()
      }
  
  
      private fun switchTab(index: Int) {
          val transaction = supportFragmentManager.beginTransaction()
          when (index) {
              0 -> {
                  transaction.show(mHomeFragment)
                          .hide(mMirrorFragment)
                          .hide(mBbsFragment)
                          .hide(mMineFragment)
                          .commitAllowingStateLoss()
              }
              1 -> {
                  transaction.show(mMirrorFragment)
                          .hide(mHomeFragment)
                          .hide(mBbsFragment)
                          .hide(mMineFragment)
                          .commitAllowingStateLoss()
              }
              2 -> {
                  transaction.show(mBbsFragment)
                          .hide(mHomeFragment)
                          .hide(mMirrorFragment)
                          .hide(mMineFragment)
                          .commitAllowingStateLoss()
              }
              3 -> {
                  transaction.show(mMineFragment)
                          .hide(mHomeFragment)
                          .hide(mMirrorFragment)
                          .hide(mBbsFragment)
                          .commitAllowingStateLoss()
              }
          }
      }
  }
  

• adapter使用

  package com.bidostar.kotlindemo.adapter
  
  import com.bidostar.kotlindemo.R
  import com.bidostar.kotlindemo.bean.MovieBean
  import com.bumptech.glide.Glide
  import com.chad.library.adapter.base.BaseQuickAdapter
  import com.chad.library.adapter.base.BaseViewHolder
  
  /**
   * @author zsh27
   * @date 2017/12/14.
   * description .
   * @since 0
   */
  class HomeAdapter(layoutResId: Int) : BaseQuickAdapter<MovieBean, BaseViewHolder>(layoutResId) {
      init {
  
      }
  
      constructor() : this(R.layout.home_movie_item)
  
      override fun convert(helper: BaseViewHolder?, item: MovieBean?) {
          if (item != null) {
              helper?.setText(R.id.tv_name, item.movieName)
              helper?.setText(R.id.tv_desc, item.name)
              Glide.with(mContext)
                      .load(item.img)
                      .into(helper?.getView(R.id.iv_cover))
          }
      }
  
  }
  
  

项目实战

kotlin&java混编

1. 项目配置

   project级的gradle配置
   dependencies {
           classpath 'com.android.tools.build:gradle:3.0.1'
           classpath 'com.tencent.bugly:tinker-support:1.1.1'
           // NOTE: Do not place your application dependencies here; they belong
           // in the individual module build.gradle files
           classpath 'com.jakewharton:butterknife-gradle-plugin:8.4.0'
           classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
       }
       
   module级的gradle配置
   apply plugin: 'com.android.application'
   apply plugin: 'kotlin-android'
   apply plugin: 'kotlin-android-extensions'
   apply plugin: 'kotlin-kapt'
   
   dependencies {
       implementation fileTree(include: ['*.jar'], dir: 'libs')
       testImplementation "junit:junit:$rootProject.dependVersion.junit"
       implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
       implementation "com.android.support:design:$rootProject.dependVersion.support"
       implementation "com.android.support.constraint:constraint-layout:$rootProject.dependVersion.constraint_layout"
       }
   
   

2. 常量类

   object NetConstant {
   
   /**
    * 连接超时
    */
   const val DEFAULT_CONNECT_TIME_OUT = 15L
   /**
    * 读取超时
    */
   const val DEFAULT_READ_TIME_OUT = 15L
   /**
    * 写入超时
    */
   const val DEFAULT_WRITE_TIME_OUT = 30L
   
   }
   

3. 单例类

   class HttpManager private constructor() {
           /**
        * 构造方法私有
        */
       init {
           Logger.d("HttpManager:" + "init:" + "_debug:" + Debug)
           initRetrofit()
       }
       companion object {
       /**
        * 单例对象
        */
       var BaseUrl: String? = null
       var BaseResourceUrl: String? = null
       var Debug = false
       var InterceptorList: List<Interceptor>? = null
       var NetworkInterceptorList: List<Interceptor>? = null
       /**
        * 获取HttpManager
        *
        * @return HttpManager实例 instance
        */
       val instance: HttpManager
           get() {
               return Holder.INSTANCE
           }
   
       fun paramsBuild(): HttpManager.ParamsBuild {
           return HttpManager.ParamsBuild()
       }
   
       /**
        * 自定义Retrofit示例
        * 可以设置一些自定义参数,通过buildRetrofit()构建Retrofit实例
        * 或者通过buildApiService()直接构建一个网络请求接口
        *
        * @return 自定义RetrofitBuilder http builder . builder
        */
       fun newBuilder(): HttpBuilder.Builder {
           return HttpBuilder.Builder()
           }
       }
   
   }
   
   使用方法
   1. java文件中使用
        HttpManager.Companion.getInstance()
               .create(IAppServices.class)
               .getDeviceActivateStatus()
               .compose(RxSchedulers.INSTANCE.<com.bidostar.netlibrary.BaseResponse<DeviceStatusBean>>applyIoSchedulers())
               .compose(this.<com.bidostar.netlibrary.BaseResponse<DeviceStatusBean>>bindToLifecycle())
   2. kotlin文件中使用
       HttpManager.instance
               .create(IAppServices::class.java)
               .deleteDevicePic(mDeviceCode, bean.id.toLong())
               .compose(RxSchedulers.applyIoSchedulers())
               .compose(this.bindToLifecycle())
   
   
   

4. view控件

   1. findViewById()

          var mTvTitle = findViewById(R.id.tv_title)
          var mIvBack = findViewById(R.id.iv_back)
      
      

   2. kotlin注解方式

      import kotlinx.android.synthetic.main.activity_mirror_album_detail.*
      
      mAdapter = AlbumPagerAdapter(mContext)
      view_pager.adapter = mAdapter
      view_pager.addOnPageChangeListener(this)
      mAdapter!!.setNewData(mItemList)
      view_pager.currentItem = mIndex
      
      mIvBack.setOnClickListener {
          finish()
      }
      tv_delete.setOnClickListener(this)
      tv_download.setOnClickListener(this)
      
      

5. mvp使用

   M层
   class DeviceCaptureModelImpl : BaseModel(), DeviceCaptureContract.IDeviceCaptureModel {
   
       override fun getLastPicture(alarmId: Int, deviceCode: Long, alarmDay: String, pageSize: Int, respType: String): Observable<BaseResponse<List<MirrorAlbumBean>>> {
           return HttpManager.instance
                   .create(IAppServices::class.java)
                   .getDeviceAlarm(alarmId, deviceCode, alarmDay, pageSize, respType)
                   .compose(RxSchedulers.applyIoSchedulers())
       }
   
       override fun getDeviceStatus(deviceCode: Long, rousing: Boolean): Observable<BaseResponse<Int>> {
           return HttpManager.instance.create(IAppServices::class.java)
                   .deviceStatus(deviceCode, rousing)
                   .compose(RxSchedulers.applyIoSchedulers())
       }
   
       override fun devicecapture(deviceCode: Long): Observable<BaseResponse<CaptureBean>> {
           return HttpManager.instance.create(IAppServices::class.java)
                   .deviceCapture(deviceCode)
                   .compose(RxSchedulers.applyIoSchedulers())
       }
   
       override fun sendMessage(deviceCode: Long, content: String): Observable<BaseResponse<String>> {
           return HttpManager.instance.create(IAppServices::class.java)
                   .sendTextToDevice(deviceCode, content)
                   .compose(RxSchedulers.applyIoSchedulers())
       }
   }
   
   P层
   class DeviceCapturePresenterImpl : BasePresenter<DeviceCaptureContract.IDeviceCaptureView, DeviceCaptureModelImpl>(),
       DeviceCaptureContract.IDeviceCapturePresenter {
   override fun getDeviceStatus(deviceCode: Long, rousing: Boolean) {
       m.getDeviceStatus(deviceCode, rousing)
               .compose(RxSchedulers.applyIoSchedulers())
               .subscribe(object : BaseObserver<Int>() {
                   override fun handleResult(response: BaseResponse<Int>) {
                       when (response.resultCode) {
                           BaseResponse.RET_HTTP_STATUS_OK -> {
                               when (response.data) {
                                   BaseResponse.RET_HTTP_STATUS_OK -> {
                                       v.onLine()
                                   }
                                   BaseResponse.RET_MIRROR_STATUS_NO -> {
                                       v.offLine()
                                   }
                                   BaseResponse.RET_MIRROR_STATUS_YES -> {
                                       v.onStarting()
                                   }
                               }
                           }
                           BaseResponse.RET_TIMEOUT_CODE -> {
                               v.timeOut()
                           }
                           else -> {
                               v.onError()
                               v.showErrorTip(response.errorMsg)
                           }
                       }
                   }
               })
       }
   }
   
   V层
   @Route(path = ARouterConstant.DEVICE_CAPTURE)
   class DeviceCaptureActivity : BaseMvpActivity<DeviceCapturePresenterImpl>(), DeviceCaptureContract.IDeviceCaptureView,
           Handler.Callback, DeviceConnectDialog.onMirrorConnectClickListener {
   
       private lateinit var mTvTitle: TextView
       private lateinit var mIvBack: ImageView
       private var mCar: Car? = null
       private var mHandler: WeakRefHandler? = null
       private var mIsCapture = false
       private var mContent = ""
       private var mConnectDialog: DeviceConnectDialog? = null
       override fun newPresenter(): DeviceCapturePresenterImpl {
           return DeviceCapturePresenterImpl()
       }
   
       override fun getLayoutView(savedInstanceState: Bundle?): Int {
           return R.layout.activity_device_capture
       }
   
       override fun initView(savedInstanceState: Bundle?) {
           mIvBack = findViewById(R.id.iv_back)
           mTvTitle = findViewById(R.id.tv_title)
           mIvBack.setOnClickListener {
               finish()
           }
           mTvTitle.text = "后视镜远程操控"
           mIvBack.setOnClickListener {
               finish()
           }
           ivCapture.setOnClickListener {
               mIsCapture = true
               if (mCar?.deviceType != 1) {
                   DialogUtils.showBindDialog(mContext)
                   return@setOnClickListener
               }
               ivCapture.isClickable = false
               showMirrorConnectDialog()
               p.getDeviceStatus(mCar!!.deviceCode, true)
           }
           ivAlbum.setOnClickListener {
               if (mCar?.getDeviceType() != 1) {
                   DialogUtils.showBindDialog(mContext)
                   return@setOnClickListener
               }
               ARouter.getInstance().build(ARouterConstant.DEVICE_CAPTURE_ALBUM)
                       .navigation()
           }
           tvSendMessage.setOnClickListener {
               mIsCapture = false
               if (mCar!!.deviceType != 1) {
                   DialogUtils.showBindDialog(mContext)
                   return@setOnClickListener
               }
               mContent = etMessage.text.toString().trim()
               if (TextUtils.isEmpty(mContent)) {
                   showToast("消息内容不能为空")
                   return@setOnClickListener
               }
               tvSendMessage.isClickable = false
               showMirrorConnectDialog()
               p.getDeviceStatus(mCar!!.deviceCode, true)
           }
       }
   
       override fun initData() {
           mCar = ApiCarDb.getCar(mContext)
           mHandler = WeakRefHandler(this)
           if (mCar?.deviceType == 1) {
               p.getLastPicture(207, mCar!!.deviceCode, "", 1, "list")
           }
   
       }
   }
   
   

6. java文件转换成kotlin

   java文件
       public class AlbumPagerAdapter extends PagerAdapter {
       private List<MirrorAlbumItemBean> mDataList;
       private Context mContext;
       private final LayoutInflater mInflater;
   
       public AlbumPagerAdapter(Context context) {
           mContext = context;
           mInflater = LayoutInflater.from(mContext);
           if (mDataList == null) {
               mDataList = new ArrayList<>();
           }
       }
   
       public void setNewData(List<MirrorAlbumItemBean> list) {
           if (mDataList == null) {
               mDataList = new ArrayList<>();
           }
           mDataList.clear();
           mDataList.addAll(list);
           notifyDataSetChanged();
       }
   
       @Override
       public int getCount() {
           return mDataList.size();
       }
   
       @Override
       public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
           return object == view;
       }
   
       @NonNull
       @Override
       public Object instantiateItem(@NonNull ViewGroup container, int position) {
           MirrorAlbumItemBean bean = mDataList.get(position);
           View inflate = mInflater.inflate(R.layout.device_album_viewpager_item_layout, container, false);
           ImageView imageView = inflate.findViewById(R.id.pv_image);
           TextView tvLocation = inflate.findViewById(R.id.tv_location);
   
           TextView tvTime = inflate.findViewById(R.id.tv_time);
           tvLocation.setText(TextUtils.isEmpty(bean.getLocation()) ? "位置位置" : bean.getLocation());
           tvTime.setText(bean.getAlarmTime());
   
           Glide.with(mContext)
                   .load(bean.getUrl())
                   .into(imageView);
           container.addView(inflate);
           return inflate;
       }
   
       @Override
       public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
           container.removeView((View) object);
       }
   }
   
   
   

```

class AlbumPagerAdapter(private val mContext: Context) : PagerAdapter() {
    private var mDataList: MutableList<MirrorAlbumItemBean>? = null
    private val mInflater: LayoutInflater = LayoutInflater.from(mContext)

    init {
        if (mDataList == null) {
            mDataList = ArrayList()
        }
    }

    fun setNewData(list: List<MirrorAlbumItemBean>) {
        if (mDataList == null) {
            mDataList = ArrayList()
        }
        mDataList!!.clear()
        mDataList!!.addAll(list)
        notifyDataSetChanged()
    }

    fun removeData(position: Int) {
        if (mDataList!!.size > position) {
            mDataList!!.removeAt(position)
        }
        notifyDataSetChanged()
    }

    override fun getCount(): Int {
        return mDataList!!.size
    }

    override fun isViewFromObject(view: View, `object`: Any): Boolean {
        return `object` === view
    }

    override fun instantiateItem(container: ViewGroup, position: Int): Any {
        val bean = mDataList!![position]
        val inflate = mInflater.inflate(R.layout.device_album_viewpager_item_layout, container, false)
        val imageView = inflate.findViewById<ImageView>(R.id.pv_image)
        val tvLocation = inflate.findViewById<TextView>(R.id.tv_location)

        val tvTime = inflate.findViewById<TextView>(R.id.tv_time)
        tvLocation.text = if (TextUtils.isEmpty(bean.location)) "未知位置" else bean.location
        tvTime.text = bean.alarmTime

        Glide.with(mContext)
                .load(bean.url)
                .into(imageView)
        container.addView(inflate)
        return inflate
    }

    override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
        container.removeView(`object` as View)
    }

    override fun getItemPosition(`object`: Any): Int {
        return PagerAdapter.POSITION_NONE
    }
}

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