无法在底部显示徽章导航视图

Question

我有在bottomNavigtionView上的某些项目上显示徽章的方法。在这里：

private fun addBadgeView() {
val menuView = mainNavigationView.getChildAt(0) as BottomNavigationMenuView
val itemView = menuView.getChildAt(1) as BottomNavigationItemView
val notificationBadge = LayoutInflater.from(this).inflate(R.layout.notification_badge, menuView, false)
val textView = notificationBadge.findViewById<TextView>(R.id.counter_badge)
val itemView1 = menuView.getChildAt(2) as BottomNavigationItemView
val notificationBadgeOne = LayoutInflater.from(this).inflate(R.layout.notification_badge, menuView, false)
val textView1 = notificationBadgeOne.findViewById<TextView>(R.id.counter_badge)
val itemView2 = menuView.getChildAt(3) as BottomNavigationItemView
val notificationBadge2 = LayoutInflater.from(this).inflate(R.layout.notification_badge, menuView, false)
val textView2 = notificationBadge2.findViewById<TextView>(R.id.counter_badge)
when {
sp!!.getInt("notepad_count", 0) > 99 -> textView2.text = resources.getText(R.string.more90)
sp!!.getInt("notepad_count", 0) < 99 -> textView2.text = sp!!.getInt("notepad_count", 0).toString()
sp!!.getInt("notepad_count", 0) == 0 -> textView2.visibility = View.GONE
}
if (sp!!.getString("new_receivedM", "")!!.isNotEmpty()) {
when {
Integer.parseInt(sp!!.getString("new_receivedM", "")!!) > 99 -> textView.text = resources.getText(R.string.more90)
sp!!.getString("new_receivedM", "") == "0" -> textView.visibility = View.GONE
else -> textView.text = sp!!.getString("new_receivedM", "")
}
} else run { textView.visibility = View.GONE }

if (sp!!.getString("all_jobs", "")!!.isNotEmpty()) {
when {
Integer.parseInt(sp!!.getString("all_jobs", "")!!) > 99 -> textView1.text = resources.getText(R.string.more90)
sp!!.getString("all_jobs", "") == "0" -> textView1.visibility = View.GONE
else -> textView1.text = sp!!.getString("all_jobs", "")
}
} else {
textView1.visibility = View.GONE
}
itemView.addView(notificationBadge)
itemView1.addView(notificationBadgeOne)
itemView2.addView(notificationBadge2)
}

但有时我想在某些情况下删除一些项目，所以我在这里添加了小条件：

val set = sp!!.getStringSet("disabled_app_modules", HashSet<String>())
if (set!!.isNotEmpty()) {
val list: ArrayList<String> = ArrayList()
list.addAll(set)
for (i in 0 until list.size) {
when (list[i].substring(1, list[i].length - 1)) {
"notepad" -> {
bottomNavigationView.menu.removeItem(R.id.notespec)
}
}
}
}

我检查我的bottomNavigationView是否包含以下项目：

if (bottomNavigationView.getChildAt(2) != null) {
val itemView1 = menuView.getChildAt(2) as BottomNavigationItemView
val notificationBadgeOne = LayoutInflater.from(this).inflate(R.layout.notification_badge, menuView, false)
val textView1 = notificationBadgeOne.findViewById<TextView>(R.id.counter_badge)
if (sp!!.getString("all_jobs", "")!!.isNotEmpty()) {
when {
Integer.parseInt(sp!!.getString("all_jobs", "")!!) > 99 -> textView1.text = resources.getText(R.string.more90)
sp!!.getString("all_jobs", "") == "0" -> textView1.visibility = View.GONE
else -> textView1.text = sp!!.getString("all_jobs", "")
}
} else {
textView1.visibility = View.GONE
}
itemView1.addView(notificationBadgeOne)
}

结果我没有看到任何徽章，因为该项目null但它是可见和可点击的。也许我在某处犯了一些错误？

更新

我明白我在哪里犯了一个错误：

if (bottomNavigationView.getChildAt(2) != null) 

此行将始终为 null。所以我删除了这个条件，但我有一个错误：

kotlin.TypeCastException: null cannot be cast to non-null type com.google.android.material.bottomnavigation.BottomNavigationItemView

此行上的哪些点：

itemView2.addView(notificationBadge2)

据我了解，我打电话给已删除的项目。但是我不知道如何检查项目是否被删除。也许有人知道该怎么做？

Answer 1

让我们让它变得简单...:)

https://developer.android.com/reference/com/google/android/material/bottomnavigation/BottomNavigationView

https://material.io/develop/android/components/badging/

implementation 'com.google.android.material:material:1.2.0-alpha03'

风格.xml

<style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>

你的BottomNavigationView会像

<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:menu="@menu/bottom_nav_menu"
/>

在活动中

val navBar = findViewById<BottomNavigationView>(R.id.bottom_navigation)
var badge = navBar.getOrCreateBadge(R.id.action_add) //R.id.action_add is menu id
badge.number = 2
badge.backgroundColor = //your color
badge.badgeTextColor = // your textcolor