<ImageView
        android:id="@+id/car"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@mipmap/car"/>

ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(car, "translationX", 0f, -200);
            objectAnimator.setDuration(2000);
            objectAnimator.start();

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/car"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@mipmap/car"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:orientation="horizontal"
        android:layout_below="@id/car"
        android:layout_marginTop="100dp">
        <Button
            android:id="@+id/left"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Forward"
            android:textAllCaps="false"/>
        <Button
            android:id="@+id/reset"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Reset"
            android:textAllCaps="false"
            android:layout_marginLeft="20dp"/>
        <Button
            android:id="@+id/right"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Backword"
            android:textAllCaps="false"
            android:layout_marginLeft="20dp"/>
    </LinearLayout>
</RelativeLayout>

package com.example.a4_10_float;

import androidx.appcompat.app.AppCompatActivity;

import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    private ImageView car;
    private Button left;
    private Button reset;
    private Button right;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        car = findViewById(R.id.car);
        left = findViewById(R.id.left);
        reset = findViewById(R.id.reset);
        right = findViewById(R.id.right);
    }

    @Override
    protected void onStart() {
        super.onStart();
        left.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Floaat(1);
            }
        });
        reset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Floaat(0);
            }
        });
        right.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Floaat(2);
            }
        });
    }
	//封裝好一個方法，開控制向左向右移動和回到初始位置
    private void Floaat(int a) {
        if (a==1) {
            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(car, "translationX", 0f, -200);
            objectAnimator.setDuration(2000);
            objectAnimator.start();
        }else if (a==0){
            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(car, "translationX", 0f, 0);
            objectAnimator.setDuration(2000);
            objectAnimator.start();
        }else if (a==2){
            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(car, "translationX", 0f, 200);
            objectAnimator.setDuration(2000);
            objectAnimator.start();
        }
    }
}