Android ListView可以出现在活动中,但可以';不要断断续续地出现
ListView可以出现在Android ListView可以出现在活动中,但可以';不要断断续续地出现,android,listview,android-fragments,kotlin,Android,Listview,Android Fragments,Kotlin,ListView可以出现在活动中,但不能出现在片段中,但是我在Kotlin和Android Studio 3.0中使用了相同的代码 这是我的片段代码: class testFrag : Fragment() { var adapter : mo3dAdapter?=null var listOfMkabala = ArrayList<MeetingDetails>() override fun onCreateView(inflater: LayoutInflater?, con
活动中,但不能出现在片段中,但是我在Kotlin和Android Studio 3.0中使用了相同的代码
这是我的片段代码:
class testFrag : Fragment() {
var adapter : mo3dAdapter?=null
var listOfMkabala = ArrayList<MeetingDetails>()
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater!!.inflate(R.layout.fragment_test, container, false)
listOfMkabala .add ( MeetingDetails(" nour1", "ahmed1" , "aya1"))
listOfMkabala .add ( MeetingDetails(" nour2", "ahmed2" , "aya2"))
listOfMkabala .add ( MeetingDetails(" nour3", "ahmed3" , "aya3"))
listOfMkabala .add ( MeetingDetails(" nour4", "ahmed4" , "aya4"))
listOfMkabala .add ( MeetingDetails(" nour5", "ahmed5" , "aya5"))
listOfMkabala .add ( MeetingDetails(" nour6", "ahmed6" , "aya6"))
adapter = mo3dAdapter (context ,listOfMkabala)
tv1.adapter = adapter
}
fun test ( view: View){
}
类testFrag:Fragment(){
var适配器:mo3dAdapter?=null
var listOfMkabala=ArrayList()
覆盖创建视图(充气机:布局充气机?、容器:视图组?、savedInstanceState:捆绑?):视图{
返回充气机!!.充气(R.layout.fragment\u测试,容器,错误)
添加(会议详情(“nour1”、“ahmed1”、“aya1”))
添加(会议详情(“nour2”、“ahmed2”、“aya2”))
添加(会议详情(“nour3”、“ahmed3”、“aya3”))
添加(会议详情(“nour4”、“ahmed4”、“aya4”))
添加(会议详情(“nour5”、“ahmed5”、“aya5”))
添加(会议详情(“nour6”、“ahmed6”、“aya6”))
adapter=mo3dapter(上下文,listOfMkabala)
tv1.adapter=适配器
}
趣味测试(视图:视图){
}
这是我的适配器:
inner class mo3dAdapter: BaseAdapter {
var listOfMkabaln= ArrayList<MeetingDetails>()
var context:Context?=null
constructor(context:Context, listOfMkabaln: ArrayList<MeetingDetails>):super(){
this.listOfMkabaln=listOfMkabaln
this.context=context
}
override fun getView(p0: Int, p1: View?, p2: ViewGroup?): View {
val mo3d = listOfMkabaln[p0]
var inflator = context!!.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
var myView = inflator.inflate(R.layout.fragment_test, null)
myView.text1.text = mo3d.name1!!
myView.text2.text = mo3d.name2!!
myView.text3.text = mo3d.name3!!
return myView
}
override fun getItem(p0: Int): Any {
return listOfMkabaln[p0]
}
override fun getItemId(p0: Int): Long {
return p0.toLong()
}
override fun getCount(): Int {
return listOfMkabaln.size
}
}
内部类mo3dapter:BaseAdapter{
var listOfMkabaln=ArrayList()
变量上下文:上下文?=null
构造函数(context:context,listOfMkabaln:ArrayList):super(){
this.listOfMkabaln=listOfMkabaln
this.context=context
}
覆盖视图(p0:Int,p1:View?,p2:ViewGroup?):视图{
val mo3d=listOfMkabaln[p0]
var充气器=context!!.getSystemService(context.LAYOUT\u充气器\u服务)作为LayoutInflater
var myView=充气机。充气(R.layout.fragment\u测试,空)
myView.text1.text=mo3d.name1!!
myView.text2.text=mo3d.name2!!
myView.text3.text=mo3d.name3!!
返回myView
}
覆盖趣味getItem(p0:Int):任意{
返回列表Mkabaln[p0]
}
覆盖有趣的getItemId(p0:Int):长{
返回p0.toLong()
}
重写fun getCount():Int{
返回listOfMkabaln.size
}
}
在初始化后,您应该在
onCreateView()
您正在使用kotlin android extensions
直接获取视图。如果您使用这种方式,则只有在创建视图后才能获取LisView
您的代码应该是这样的
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater!!.inflate(R.layout.fragment_test, container, false)
}
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
listOfMkabala .add ( MeetingDetails(" nour1", "ahmed1" , "aya1"))
listOfMkabala .add ( MeetingDetails(" nour2", "ahmed2" , "aya2"))
listOfMkabala .add ( MeetingDetails(" nour3", "ahmed3" , "aya3"))
listOfMkabala .add ( MeetingDetails(" nour4", "ahmed4" , "aya4"))
listOfMkabala .add ( MeetingDetails(" nour5", "ahmed5" , "aya5"))
listOfMkabala .add ( MeetingDetails(" nour6", "ahmed6" , "aya6"))
adapter = mo3dAdapter (context ,listOfMkabala)
tv1.adapter = adapter
}
onViewCreated()
在视图创建后运行。因此它确保您的视图已经创建
您也为适配器传递了相同的布局
在适配器代码中,将R.layout.fragment\u test
更改为模型布局
var myView = inflator.inflate(R.layout.fragment_test, null)
希望它能有所帮助:)您在onCreateView
中编写了return
语句之后的代码,我们称之为死代码(无法访问的代码)。这样您就不会在列表视图中设置适配器
遵循3个步骤作为一般方法-
在onCreate
方法中初始化所有数据。在您的情况下,在ArrayList
中添加数据将转到此处
所以这看起来像——
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
listOfMkabala .add ( MeetingDetails(" nour1", "ahmed1" , "aya1"))
listOfMkabala .add ( MeetingDetails(" nour2", "ahmed2" , "aya2"))
listOfMkabala .add ( MeetingDetails(" nour3", "ahmed3" , "aya3"))
listOfMkabala .add ( MeetingDetails(" nour4", "ahmed4" , "aya4"))
listOfMkabala .add ( MeetingDetails(" nour5", "ahmed5" , "aya5"))
listOfMkabala .add ( MeetingDetails(" nour6", "ahmed6" , "aya6"))
}
仅在onCreateView
中初始化布局资源。如下所示-
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
return inflater!!.inflate(R.layout.fragment_test, container, false)
}
这与在UI上呈现数据有关,应该在onViewCreated
方法中完成。在您的情况下,它应该像-
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
adapter = mo3dAdapter (context ,listOfMkabala)
// Init your listview
tv1 = view?.findViewById(R.id.your_listview_id);
tv1.adapter = adapter
}
确保您初始化tv1
,并且它应该是ListView
引用。不需要显式展开。双重撞击!!
应该被视为错误。请解释一下,当我在appwait上打开碎片时@Xalamadraxit崩溃了,让我检查一下。@NourMedhatPost您的崩溃报告@nourmedhatty您必须如果您正在使用Android扩展,请说明。我在这行tv1=(ListView)视图中有错误。findViewById(R.id.tv1);什么错误?这是tv1?请显示您的导入,您是否正在使用kotlin Android扩展进行UI映射您正在以Java方式进行转换。应该是视图?.findViewById(R.id.your_ListView_id)作为ListView
@NourMedhat请使用view?.findViewById(R.id.your_ListView_id)而不是(ListView)view?.findViewById(R.id.tv1)