android:gravity=“center“无效解决方法

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <androidx.swiperefreshlayout.widget.SwipeRefreshLayout android:id="@+id/home_swiperefresh" android:layout_width="match_parent" android:layout_height="match_parent" > <androidx.recyclerview.widget.RecyclerView android:id="@+id/home_recyclerview" android:layout_width="match_parent" android:layout_height="match_parent" /> </androidx.swiperefreshlayout.widget.SwipeRefreshLayout> <androidx.appcompat.widget.Toolbar android:layout_width="match_parent" android:layout_height="80dp" app:layout_constrainTop_toTopOf="parent" > <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center_vertical" android:orientation="horizontal" > <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_home_scan_24"/> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="8dp" android:layout_marginEnd="18dp" android:layout_weight="1" android:background="@color/white" android:cursorVisible="false" android:focusable="false" android:hint="搜索" android:minHeight="30dp" android:textSize="16dp" /> </LinearLayout> </androidx.appcompat.widget.Toolbar> </androidx.constraintlayout.widget.ConstraintLayout>

android 相对布局 gravity 无效,父布局为RelativeLayout，textview设置layout_gravity=