Android studio学习任务总结（五）

今天使用as完成了一个图片跟随鼠标移动的app

代码如下：

.java文件

package test.com.rabbit;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;

public class Rabbit extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_rabbit);
        //获取布局文件中的布局管理器
        FrameLayout frameLayout = (FrameLayout)findViewById(R.id.mylayout);
        //创建并实例化rabbit对象
        final RabbitView rabbit = new RabbitView(this);
        //为小兔子添加事件监听器
        rabbit.setOnTouchListener(new View.OnTouchListener(){

            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                rabbit.bitmapX = motionEvent.getX();
                rabbit.bitmapY = motionEvent.getY();
                rabbit.invalidate();
                return true;
            }
        });
        frameLayout.addView(rabbit);

    }
}

package test.com.rabbit;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;

/**
 * Created by 亮亮哥 on 2020/4/26.
 */
public class RabbitView extends View {
    //定义两个全局变量
    public float bitmapX;
    public float bitmapY;

    public RabbitView(Context context) {
        super(context);
        bitmapX=290;
        bitmapY=130;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();
        Bitmap bitmap = BitmapFactory.decodeResource(this.getResources(),R.mipmap.rabbit);
        canvas.drawBitmap(bitmap,bitmapX,bitmapY,paint);
        if(bitmap.isRecycled()){//判断
            bitmap.recycle();
        }
    }
}
xml文件：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:background="@mipmap/grassland"
    android:id="@+id/mylayout"
    tools:context="test.com.rabbit.Rabbit">


</FrameLayout>
效果如下：