如何在Android中使用Kotlin获取片段中的资源ID? [英] How to fetch resource id in fragment using kotlin in android?

问题描述

我尝试了下面提到的这段代码，但是在运行时崩溃.发生的错误是Android运行时:

I tried to this code which is mention below, but getting crash during run time. The error occurred is Android Run time:

致命异常:主要过程:com.root.specialbridge，PID:17706 kotlin.KotlinNullPointerException com.root.specialbridge.fragments.profile_fragment.WallFragments.initializeView(WallFragments.kt:49)

FATAL EXCEPTION: main Process: com.root.specialbridge, PID: 17706 kotlin.KotlinNullPointerException at com.root.specialbridge.fragments.profile_fragment.WallFragments.initializeView(WallFragments.kt:49)

class WallFragments : Fragment(){

private var wallAdapter: WallAdapter? = null
private var wall_recycler: RecyclerView? = null
private val wallArrayList: ArrayList<Wall>? = null
private var mainlayout: LinearLayout? = null
private var no_result_found_layout: RelativeLayout? = null
private var userProfileWallInterface: UserProfileWallInterface? = null
internal var wallActivityBeanse: MutableList<WallActivityBeans> = ArrayList()

override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    val view = inflater!!.inflate(R.layout.wall_fragments, container, false)
    userProfileWallInterface = UserProfileWallPresentation(activity, this)
    initializeView()
    wallAdapter = WallAdapter(activity, wallActivityBeanse)
    wall_recycler!!.adapter = wallAdapter

    return view
}
fun initializeView() {
    wall_recycler = view!!.findViewById(R.id.wall_recycler_id) as RecyclerView
    mainlayout = view!!.findViewById(R.id.mainlayout) as LinearLayout
    no_result_found_layout = view!!.findViewById(R.id.no_result_found_layout) as RelativeLayout
    wall_recycler!!.layoutManager = LinearLayoutManager(activity)
    wall_recycler!!.setHasFixedSize(true)
    if (AuthPreference(activity).isGetMemberProfile) {
        userProfileWallInterface!!.getMemberProfileWall(view!!)

    } else {
        userProfileWallInterface!!.getUserProfileWall(AuthPreference(activity).token, AuthPreference(activity).user.id, view!!)

    }
}   
companion object {
    val instance: WallFragments
        get() = WallFragments()  }}

推荐答案

添加

apply plugin: 'kotlin-android-extensions'

在应用程序级别gradle文件和

in the app level gradle file and

导入

import kotlinx.android.synthetic.main.fragment_your_fragment_name.view.*

在片段的onCreateView中(例如，如果textview的id是textView)

in the onCreateView of your fragment (e.g. if the id of your textview is textView)

override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
    // Inflate the layout for this fragment
    val view = inflater!!.inflate(R.layout.fragment_splashfragment, container, false)
    view.textView.text = "hello"   //add your view before id else getting nullpointer exception
    return view
}

更新:

在类中声明viewOfLayout而不是view.

declare viewOfLayout in your class instead of view.

class yourfragment:Fragment(){

    private lateinit var viewOfLayout: View
    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        // Inflate the layout for this fragment
        viewOfLayout = inflater!!.inflate(R.layout.fragment_splashfragment, container, false)
        viewOfLayout.textView.text = "hello"   //add your view before id else will get nullpointer exception
        return viewOfLayout
    }

}

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