android中动态修改ImageView控件的宽高度

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:gravity="center"
        android:orientation="horizontal">

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="放大" />
        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="缩小" />
    </LinearLayout>


    <ImageView
        android:id="@+id/imageView"
        android:layout_width="150dp"
        android:layout_height="150dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/img01" />

</android.support.constraint.ConstraintLayout>

package com.example.chenrui.app1;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ImageView image = findViewById(R.id.imageView);
        Button button1 = findViewById(R.id.button1);
        button1.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                ViewGroup.LayoutParams params = image.getLayoutParams();
                params.width = params.width + 50;
                params.height = params.height + 50;
                image.setLayoutParams(params);
            }
        });

        Button button2 = findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                ViewGroup.LayoutParams params = image.getLayoutParams();
                params.width = params.width - 50;
                params.height = params.height - 50;
                image.setLayoutParams(params);
            }
        });
    }
}