Android studio 如何让图片在 FloatingActionButton 居中

In Android studio how to let a image in FloatingActionButton center

    <com.google.android.material.floatingactionbutton.FloatingActionButton
    android:id="@+id/floatingActionButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:clickable="true"
    android:contentDescription="TODO"
    android:focusable="true"
    android:scaleType="fitCenter"
    app:backgroundTint="@color/black"
    app:fabSize="auto"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/checkBox6"
    app:maxImageSize="100dp"
    app:srcCompat="@drawable/add"
    app:tint="@color/blue" />

我想让Button中的图片居中,我试过用constrained layout,但是在FloatingActionButton里面不行。 我更改了我的代码,但没有用。

    <com.google.android.material.floatingactionbutton.FloatingActionButton
    android:id="@+id/floatingActionButton2"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:layout_marginEnd="30dp"
    android:layout_marginRight="30dp"
    android:layout_marginBottom="60dp"
    android:clickable="true"
    app:backgroundTint="#000000"
    app:fabCustomSize="50dp"
    app:elevation="0dp"
    app:borderWidth="0dp"
    app:fabSize="normal"
    app:pressedTranslationZ="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:maxImageSize="100dp"
    app:srcCompat="@drawable/add"
    app:tint="@color/blue" />

<com.google.android.material.floatingactionbutton.FloatingActionButton

<com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/fab"
            app:backgroundTint="@color/colortoolbar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="@dimen/fab_margin"
            app:srcCompat="@drawable/world"
            app:fabSize="mini"/>

你给了他们不同的保证金sizes.remove。

最终代码为

    <com.google.android.material.floatingactionbutton.FloatingActionButton
    android:id="@+id/floatingActionButton2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="32dp"
    android:layout_marginRight="32dp"
    android:layout_marginBottom="40dp"
    android:clickable="true"
    app:backgroundTint="#FFFFFF"
    app:fabSize="mini"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:maxImageSize="91dp"
    app:srcCompat="@drawable/add"
    app:tint="@color/blue" />