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主要知识点:Rxjava的interval操作符,AndroidSchedulers.mainThread()线程
Kotlin的主函数默认值
import android.content.Context
import android.support.v7.appcompat.R
import android.support.v7.widget.AppCompatButton
import android.util.AttributeSet
import io.reactivex.Observable
import io.reactivex.android.schedulers.AndroidSchedulers
import io.reactivex.disposables.Disposable
import java.util.concurrent.TimeUnit
class CountdownButton(mContext: Context, mAttributes: AttributeSet? = null, mDefStyleAttr: Int = R.attr.buttonStyle) : AppCompatButton(mContext, mAttributes, mDefStyleAttr) {
constructor(context: Context, attributes: AttributeSet) : this(mContext = context, mAttributes = attributes)
constructor(context: Context) : this(mContext = context)
var count: Int = 59
lateinit var subscribe: Disposable//保存订阅者
fun start() {
isClickable = false//禁用点击,防止重复操作
text = "${count + 1}s"
subscribe = Observable.interval(1, TimeUnit.SECONDS)//按时间间隔发送整数的Observable
.observeOn(AndroidSchedulers.mainThread())//切换到主线程修改UI
.subscribe {
val show = count - it
if (show < 0.toLong()) {//当倒计时小于0,计时结束
stop()
return@subscribe//使用标记跳出方法
}
text = "${show}s"
}
}
/**
* 结束计时,重新开始
*/
fun stop() {
subscribe.dispose()//取消订阅
text = "重新获取"
isClickable = true//重新开启点击事件
return
}
}
