将 OnClickListener 添加到 headerLayout 中的元素

Question

我正在尝试制作一个应用程序，您可以在其中通过单击图像视图来切换抽屉，但是每次我在 main activity[的 OnCreate 中设置 onClickListener 时似乎都会遇到严重错误=12=]

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.myapplication, PID: 7921
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myapplication/com.example.myapplication.activities.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3356)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3500)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2049)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7523)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.myapplication.activities.MainActivity.onCreate(MainActivity.kt:43)
        at android.app.Activity.performCreate(Activity.java:7984)
        at android.app.Activity.performCreate(Activity.java:7973)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3329)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3500) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2049) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7523) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)

已经挖了半个小时没有结果，关于如何做到这一点有什么提示吗？

除此之外其他一切正常。为了以防万一你想知道，这里有一些重要的代码：

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        setUpActionBar()

        showProgressDialog(resources.getString(R.string.please_wait))
        FirestoreClass().loadUserData(this)

       
        nav_view_main.setNavigationItemSelectedListener(this)

        iv_cancel_icon.setOnClickListener {
            toggleDrawer()
        }
    }

    private fun toggleDrawer(){
        if(drawer_layout_main.isDrawerOpen(GravityCompat.START)){
            drawer_layout_main.closeDrawer(GravityCompat.START)
        } else {
            drawer_layout_main.openDrawer(GravityCompat.START)
        }
    }

    private fun setUpActionBar(){

        setSupportActionBar(toolbar_main_activity)

        toolbar_main_activity.setNavigationIcon(R.drawable.ic_action_navigation_menu)

        toolbar_main_activity.setNavigationOnClickListener {
            toggleDrawer()
        }

        getSupportActionBar()!!.setDisplayShowTitleEnabled(false)

    }

Answer 1

上面共享的 link 中的 Kotlin 代码：

//Getting navigation view child and modifying its data
val navigationView = findViewById(your_navigation_view_id_in_drawer_layout)
val headerview = navigationView.getHeaderView(0)
val profilename = headerview.findViewById(your_view_id)
profilename.text = "text"

//Setting on click listener on header child
val child = headView.findViewById(child_id)
child.setOnClickListener{ view ->
    //Code to execute on click
}

如果这仍然不能解决您的问题，请在评论中分享 XML 代码，然后将在此基础上为您提供解决方案。

将 OnClickListener 添加到 headerLayout 中的元素

Add OnClickListener to elements inside headerLayout

xml

android

kotlin

drawerlayout