Activity的跳转一般通过Theme设置即可，但是Framment的跳转除了NavigationUI类提供的方法会有动画以外，直接调用navigate方法是没有动画的。

网上的实现个人认为比较麻烦，帮自己写了一套，主要就是自定义NavHostFragement和FragmentNavigator，设置上自定义的动画：

import android.content.Context;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.FragmentManager;
import androidx.navigation.NavBackStackEntry;
import androidx.navigation.NavDestination;
import androidx.navigation.NavOptions;
import androidx.navigation.Navigator;
import androidx.navigation.fragment.FragmentNavigator;


import java.util.List;

@Navigator.Name("fragment")
public class DefFragmentNavigator extends FragmentNavigator {

    public DefFragmentNavigator(@NonNull Context context, @NonNull FragmentManager fragmentManager, int containerId) {
        super(context, fragmentManager, containerId);
    }

    @Override
    public void navigate(@NonNull List<NavBackStackEntry> entries, @Nullable NavOptions navOptions, @Nullable Navigator.Extras navigatorExtras) {
        navOptions = NavUtils.adjustDefaultAnim(navOptions);
        super.navigate(entries, navOptions, navigatorExtras);
    }

    @Nullable
    @Override
    public NavDestination navigate(@NonNull Destination destination, @Nullable Bundle args, @Nullable NavOptions navOptions, @Nullable Navigator.Extras navigatorExtras) {
        navOptions = NavUtils.adjustDefaultAnim(navOptions);
        return super.navigate(destination, args, navOptions, navigatorExtras);
    }
}

import android.view.View;

import androidx.annotation.NonNull;
import androidx.navigation.NavHostController;
import androidx.navigation.Navigator;
import androidx.navigation.fragment.FragmentNavigator;
import androidx.navigation.fragment.NavHostFragment;


public class DefNavHostFragment extends NavHostFragment {

    @Override
    protected void onCreateNavHostController(@NonNull NavHostController navHostController) {
        super.onCreateNavHostController(navHostController);
    }

    @NonNull
    @Override
    protected Navigator<? extends FragmentNavigator.Destination> createFragmentNavigator() {
        return new DefFragmentNavigator(requireContext(), getChildFragmentManager(), getContainerId());
    }

    private int getContainerId() {
        int id = getId();
        if (id != 0 && id != View.NO_ID) {
            return id;
        } else {
            return R.id.nav_host_fragment_container;
        }
        // Fallback to using our own ID if this Fragment wasn't added via
        // add(containerViewId, Fragment)
    }
}

import androidx.navigation.NavOptions;


public class NavUtils {

    private static final NavOptions.Builder builder = new NavOptions.Builder()
        .setEnterAnim(R.anim.left_slide_in)
        .setExitAnim(R.anim.no_anim)
        .setPopEnterAnim(R.anim.no_anim)
        .setPopExitAnim(R.anim.left_slide_out);

    public static NavOptions defaultNavOptions = builder.build();

    /**
     * 自定义跳转又想带默认动画的，应使用此方法创建基础builder
     */
    public static NavOptions.Builder navBuilder() {
        return builder;
    }

    public static NavOptions adjustDefaultAnim(NavOptions navOptions) {
        if (navOptions == null) {
            navOptions = defaultNavOptions;
        }
        return navOptions;
    }

}

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:name="com.****.DefNavHostFragment"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_main"/>

</androidx.constraintlayout.widget.ConstraintLayout>

然后正常调用导航方法即可，在没有明确设置跳转动画时，会添加默认动画，也可以指定跳转动画。