1、場(chǎng)景描述

com.google.android.material.floatingactionbutton.FloatingActionButton 控件在AndroidStudio中預(yù)覽，圖標(biāo)是什么顏色，就顯示什么顏色，但是一運(yùn)行到手機(jī)，則全變成黑色圖標(biāo)了。

• 嘗試修改圖標(biāo)顏色，無(wú)果；

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="16dp"
    android:height="16dp"
    android:viewportWidth="1024"
    android:viewportHeight="1024">
  <path
      android:pathData="M318.74,178.49C238.25,185.48 178.29,256.45 178.29,337.26v2.88c0,80.96 65.3,146.29 145.83,146.29h137.98a24.72,24.72 0,0 0,24.72 -24.72V332.16c0,-89.76 -76.65,-161.61 -168.08,-153.67zM691.44,177.89c-85.19,0 -154.27,69.07 -154.27,154.26v129.55a24.72,24.72 0,0 0,24.72 24.72h129.55C776.64,486.43 845.71,417.35 845.71,332.16c0,-85.19 -69.07,-154.26 -154.27,-154.26zM178.29,691.91c0.04,85.15 69.05,154.16 154.2,154.2 85.97,0.04 154.33,-72.87 154.33,-158.85v-112.09c0,-26.57 -11.04,-37.6 -24.68,-37.6H337.14C251.16,537.57 178.25,605.93 178.29,691.91zM686.33,537.57H561.9a24.72,24.72 0,0 0,-24.72 24.72v129.55c0,85.19 69.07,154.26 154.26,154.26 86.16,0 155.82,-70.64 154.24,-157.15 -1.54,-84.92 -74.4,-151.38 -159.34,-151.38z"
      android:fillColor="#ffffff00"/>
</vector>

• 嘗試修改tint屬性，無(wú)果；

android:tint="#ffff0000"

• 嘗試修改圖標(biāo)引入方式，無(wú)果

android:src="@drawable/ic_more"
app:srcCompat="@drawable/ic_more"

• ……

2、發(fā)現(xiàn)原因

各種修改都沒(méi)有效果，但是預(yù)覽界面是有效果的，考慮到運(yùn)行的時(shí)候用的別的主題，可能會(huì)有影響，然后切換到默認(rèn)主題，問(wèn)題解決

3、總結(jié)

下面這主題會(huì)導(dǎo)致FloatingActionButton圖標(biāo)顏色時(shí)黑色，無(wú)法改變，慎用。

Theme.MaterialComponents.DayNight.NoActionBar