Kotlin let with run apply also filter if常规用法笔记

仅供个人学习参考

let

mVideoPlayer?.let {
	   it.setVideoView(activity.course_video_view)
	   it.setControllerView(activity.course_video_controller_view)
	   it.setCurtainView(activity.course_video_curtain_view)
}
	

with

val item = getItem(position)?: return
   
   with(item){
   
      holder.tvNewsTitle.text = StringUtils.trimToEmpty(titleEn)
	   holder.tvNewsSummary.text = StringUtils.trimToEmpty(summary)
	   holder.tvExtraInf.text = "难度：$gradeInfo | 单词数：$length | 读后感: $numReviews"
   }

run

fun main(args: Array) {
    val user = User("Kotlin", 1, "1111111")

    val result = user.run {
        println("my name is $name, I am $age years old, my phone number is $phoneNum")
        1000
    }
    println("result: $result")
}

apply

fun main(args: Array) {
    val user = User("Kotlin", 1, "1111111")

    val result = user.apply {
        println("my name is $name, I am $age years old, my phone number is $phoneNum")
        1000
    }
    println("result: $result")
}

mSheetDialogView = View.inflate(activity, R.layout.biz_exam_plan_layout_sheet_inner, null).apply{
   course_comment_tv_label.paint.isFakeBoldText = true
   course_comment_tv_score.paint.isFakeBoldText = true
   course_comment_tv_cancel.paint.isFakeBoldText = true
   course_comment_tv_/confirm/i.paint.isFakeBoldText = true
   course_comment_seek_bar.max = 10
   course_comment_seek_bar.progress = 0

}

mSectionmetaData?.apply{

//mSectionmetaData不为空的时候操作mSectionmetaData

}?.questionnaire?.apply{

//questionnaire不为空的时候操作questionnaire

}?.section?.apply{

//section不为空的时候操作section

}?.sectionArticle?.apply{

//sectionArticle不为空的时候操作sectionArticle

}

also

fun main(args: Array) {
    val result = "testLet".also {
        println(it.length)
        1000
    }
    println(result)
}

filter

data.item.filter { it.useStatus == ORDERSTATUS_WAIT_TO_PAY_ZERO && it.checkExpire == true && it.status == true }
        .forEach { mList.add(it) }

val list = message.data.filter {
     strS.contains(it.symbol)
}

if

 var a=10
 var b=20
 var c = if(a>b) a else b
 var c:String=if (a>b){
          //这里省略一千行代码
          "奔波儿霸"
      }else{
          //这里省略一千行代码
          "霸波儿奔"
      }

转自:https://blog.csdn.net/guoxinyu1207/article/details/100031813
https://blog.csdn.net/u013064109/article/details/78786646/
https://blog.csdn.net/mlsnatalie/article/details/81588155