[移动开发]Android：BottomNavigationView相关

菜鸡记录帖：

和ViewPager2联动

fun BottomNavigationView.setUpWithViewPager2(viewPager2: ViewPager2) {
    val map = mutableMapOf<MenuItem, Int>()
    if (this.menu.size != viewPager2.adapter?.itemCount) error("viewpager2数量需要和BottomNavigationView数量相同")
    this.menu.forEachIndexed { index, item ->
        map[item] = index
    }

    viewPager2.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
        override fun onPageSelected(position: Int) {
            super.onPageSelected(position)
            this@setUpWithViewPager2.selectedItemId =
                this@setUpWithViewPager2.menu.getItem(position).itemId
        }
    })

    this.setOnNavigationItemSelectedListener {
        val index = map[it] ?: error("asdasd")
        Log.d("TAG", "setUpWithViewPager2: index = $index")
        viewPager2.setCurrentItem(index, true)
        return@setOnNavigationItemSelectedListener true
    }
}

BottomNavigationView选中效果修改和水波纹修改

1.新建color文件夹

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/design_default_color_secondary" android:state_checked="true" />
    <item android:color="#999" android:state_checked="false" />
</selector>

1）选中icon：itemIconTint

2）选中字体颜色：itemTextColor

3）水波纹颜色：itemRippleColor

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