Android get（位置）显示在空引用上

所以，我有两个不同适配器的recyclerview。如果单击按钮，我想显示其中一个。另一个适配器工作正常。但不使用第二个适配器

身体

09-07 21:41:37.000 11177-11219/com.example.android.footballmatchschedule I/System.out: {"events":[{"idEvent":"576511","idSoccerXML":"389896","strEvent":"Huddersfield Town vs Crystal Palace","strFilename":"English Premier League 2018-09-15 Huddersfield Town vs Crystal Palace","strSport":"Soccer","idLeague":"4328","strLeague":"English Premier League","strSeason":"1819","strDescriptionEN":null,"strHomeTeam":"Huddersfield Town","strAwayTeam":"Crystal Palace","intHomeScore":null,"intRound":"5","intAwayScore":null,"intSpectators":null,"strHomeGoalDetails":null,"strHomeRedCards":null,"strHomeYellowCards":null,"strHomeLineupGoalkeeper":null,"strHomeLineupDefense":null,"strHomeLineupMidfield":null,"strHomeLineupForward":null,"strHomeLineupSubstitutes":null,"strHomeFormation":null,"strAwayRedCards":null,"strAwayYellowCards":null,"strAwayGoalDetails":null,"strAwayLineupGoalkeeper":null,"strAwayLineupDefense":null,"strAwayLineupMidfield":null,"strAwayLineupForward":null,"strAwayLineupSubstitutes":null,"strAwayFormation":null,"intHomeShots":null,"intAwayShots":null,"dateEvent":"2018-09-15","strDate":"15\/09\/18","strTime":"14:00:00+00:00","strTVStation":null,"idHomeTeam":"133932","idAwayTeam":"133632","strResult":null,"strCircuit":null,"strCountry":null,"strCity":null,"strPoster":null,"strFanart":null,"strThumb":null,"strBanner":null,"strMap":null,"strLocked":"unlocked"},{"idEvent":"576512","idSoccerXML":"389897","strEvent":"Man City vs Fulham","strFilename":"English Premier League 2018-09-15 Man City vs Fulham","strSport":"Soccer","idLeague":"4328","strLeague":"English Premier League","strSeason":"1819","strDescriptionEN":null,"strHomeTeam":"Man City","strAwayTeam":"Fulham","intHomeScore":null,"intRound":"5","intAwayScore":null,"intSpectators":null,"strHomeGoalDetails":null,"strHomeRedCards":null,"strHomeYellowCards":null,"strHomeLineupGoalkeeper":null,"strHomeLineupDefense":null,"strHomeLineupMidfield":null,"strHomeLineupForward":null,"strHomeLineupSubstitutes":null,"strHomeFormation":null,"strAwayRedCards":null,"strAwayYellowCards":null,"strAwayGoalDetails":null,"strAwayLineupGoalkeeper":null,"strAwayLineupDefense":null,"strAwayLineupMidfield":null,"strAwayLineupForward":null,"strAwayLineupSubstitutes":null,"strAwayFormation":null,"intHomeShots":null,"intAwayShots":null,"dateEvent":"2018-09-15","strDate":"15\/09\/18","strTime":"14:00:00+00:00","strTVStation":null,"idHomeTeam":"133613","idAwayTeam":"133600","strResult":null,"strCircuit":null,"strCountry":null,"strCity":null,"strPoster":null,"strFanart":null,"strThumb":null,"strBanner":null,"strMap":null,"strLocked":"unlocked"},{"idEvent":"576513","idSoccerXML":"389898","strEvent":"Newcastle vs Arsenal","strFilename":"English Premier League 2018-09-15 Newcastle vs Arsenal","strSport":"Soccer","idLeague":"4328","strLeague":"English Premier League","strSeason":"1819","strDescriptionEN":null,"strHomeTeam":"Newcastle","strAwayTeam":"Arsenal","intHomeScore":null,"intRound":"5","intAwayScore":null,"intSpectators":null,"strHomeGoalDetails":null,"strHomeRedCards":null,"strHomeYellowCards":null,"strHomeLineupGoalkeeper":null,"strHomeLineupDefense":null,"strHomeLineupMidfield":null,"strHomeLineupForward":null,"strHomeLineupSubstitutes":null,"strHomeFormation":null,"strAwayRedCards":null,"strAwayYellowCards":null,"strAwayGoalDetails":null,"strAwayLineupGoalkeeper":null,"strAwayLineupDefense":null,"strAwayLineupMidfield":null,"strAwayLineupForward":null,"strAwayLineupSubstitutes":null,"strAwayFormation":null,"intHomeShots":null,"intAwayShots":null,"dateEvent":"2018-09-15","strDate":"15\/09\/18","strTime":"14:00:00+00:00","strTVStation":null,"idHomeTeam":"134777","idAwayTeam":"133604","strResult":null,"strCircuit":null,"strCountry":null,"strCity":null,"strPoster":null,"strFanart":null,"strThumb":null,"strBanner":null,"strMap":null,"strLocked":"unlocked"},{"idEvent":"576515","idSoccerXML":"389900","strEvent":"Bournemouth vs Leicester","strFilename":"English Premier League 2018-09-15 Bournemouth vs Leicester","strSport":"Soccer","idLeague":"4328","strLeague":"English Premier League","strSeason":"1819","strDescriptionEN":null,"strHomeTeam":"Bournemout

NextMatch类别

class NextMatch(val event: List<Event>)
class Event(val strDate: String, val strHomeTeam: String, val strAwayTeam: String)

MainAdapter.kt文件：

class MainAdapter(val nextMatch: NextMatch): RecyclerView.Adapter<CustomViewHolder>(){

//Adapter Next Match

override fun getItemCount(): Int {
    return 15
}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder {
    val layoutInflater = LayoutInflater.from(parent.context)
    val callForRow = layoutInflater.inflate(R.layout.item_row,parent,false)
    return CustomViewHolder(callForRow)
}

override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
    holder.view.team_home.text =  nextMatch.event.get(position).strHomeTeam
    holder.view.team_away.text =  nextMatch.event.get(position).strAwayTeam
    holder.view.time_schedule.text = nextMatch.event.get(position).strDate
}

}

---

它显示了API中的get（position）函数试图从null对象获取它。怎么可能呢？我的意思是如何解决这个问题？

怀疑您的

NextMatch

是java定义的类型，其中

事件可以为null。
尝试将
onBindViewHolder
功能更改为以下内容

fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
    val event = nextMatch.event
    if (event != null) {
        holder.view.team_home.text = event.get(position).strHomeTeam
        holder.view.team_away.text = event.get(position).strAwayTeam
        holder.view.time_schedule.text = event.get(position).strDate
    } else {
        Log.d("TAG", "event is null!!")
    }
}

如果您看到日志
事件为空
，则确认您需要先在
nextMatch
对象中设置
事件
，然后再使用它

已更新

根据其他共享信息，问题是由于
NextMatch
的
event
变量与主体JSON名称
events
不匹配造成的

因此，要解决这个问题，只需更改

class NextMatch(val event: List<Event>)

class NextMatch（val事件：列表）

到

class NextMatch（val事件：列表）

然后gson反序列化将起作用，其中
事件现在不再为null。
请怀疑您的
NextMatch
是java定义的类型，其中
事件可能为null。
尝试将
onBindViewHolder
功能更改为以下内容

fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
    val event = nextMatch.event
    if (event != null) {
        holder.view.team_home.text = event.get(position).strHomeTeam
        holder.view.team_away.text = event.get(position).strAwayTeam
        holder.view.time_schedule.text = event.get(position).strDate
    } else {
        Log.d("TAG", "event is null!!")
    }
}

如果您看到日志
事件为空
，则确认您需要先在
nextMatch
对象中设置
事件
，然后再使用它

已更新

根据其他共享信息，问题是由于
NextMatch
的
event
变量与主体JSON名称
events
不匹配造成的

因此，要解决这个问题，只需更改

class NextMatch(val event: List<Event>)

class NextMatch（val事件：列表）

到

class NextMatch（val事件：列表）

然后gson反序列化将起作用，其中
事件现在不再为null。
您的RecyclerView适配器的项目计数是常量，您确定吗

override fun getItemCount(): Int {
     return 15
}

您的RecyclerView适配器的项目计数为常量，您确定吗

override fun getItemCount(): Int {
     return 15
}

在
onBindViewHolder
中运行代码之前，请检查
nextMatch.event
是否不为空。删除帖子时要小心，您不希望以帖子禁令告终。可以我的错。我不知道，你却告诉我。非常感谢。欢迎使用@rayhanahaputra的副本。这就是我提到它的原因。在
onBindViewHolder
中运行代码之前，请检查
nextMatch.event
是否不为空。删除帖子时要小心，你不希望最后出现帖子禁令。可以我的错。我不知道，你却告诉我。非常感谢。欢迎使用@rayhanahaputra的副本。这就是我提到它的原因。是的，我看到了。从API获取Json函数是否有问题？可能是。因此，这个回收器视图或适配器没有问题。错误的地方是你的
nextMatch
变量的设置。我已经在我的帖子中添加了这个函数。我不认为他们有什么问题，你能不能提供
正文中的内容以及
NextMatch
的格式是什么？找到问题，并提出解决方案，将
事件更改为
事件
是的，我看到了日志。从API获取Json函数是否有问题？可能是。因此，这个回收器视图或适配器没有问题。错误的地方是你的
nextMatch
变量的设置。我已经在我的帖子中添加了这个函数。我不认为他们有什么问题，你能不能提供
正文中的内容以及
NextMatch
的格式是什么？找到问题，并提出解决方案，将
事件改为
事件。我的错。我可以改为使用nextMatch.events.count（）。谢谢你的提醒。真的很感激。在我看来这是正确的。这是OP遇到的问题的真正根源。当
getItemCount（）
返回正确的值时，无需检查
null
！哦，是的。我的错。我可以改为使用nextMatch.events.count（）。谢谢你的提醒。真的很感激。在我看来这是正确的。这是OP遇到的问题的真正根源。当
getItemCount（）
返回正确的值时，无需检查
null
！