Android_(游戏)打飞机02（游戏背景滚动） _Android_

少年乘勇气，百战过乌孙。这篇文章主要讲述Android_(游戏)打飞机02：游戏背景滚动相关的知识，希望能为你提供帮助。

(游戏)打飞机01：前言传送门
(游戏)打飞机02：游戏背景滚动传送门
(游戏)打飞机03：控制玩家飞机传送门
(游戏)打飞机04：绘画敌机、添加子弹传送门
(游戏)打飞机05：处理子弹，击中敌机，添加计分板传送门
(游戏)打飞机06：后续传送门

游戏背景滚动效果

文章图片

【Android_(游戏)打飞机02（游戏背景滚动）】

文章图片

package com.example.administrator.myapplication; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.WindowManager; import java.util.ArrayList; import java.util.List; /** * Created by Administrator on 2018/8/9. */public class dafeijiGameView extends SurfaceView implements SurfaceHolder.Callback,Runnable{private Bitmap my; //自己 private Bitmap baozha; //爆炸 private Bitmap bg; //背景 private Bitmap diren; //敌人 private Bitmap zidan; //子弹 private Bitmap erjihuancun; //二级缓存 private WindowManager windowManager; //获得界面长宽高 private int display_w; //界面的宽 private int display_h; //界面的高 private List< GameImage> gameImage = new ArrayList(); public dafeijiGameView(Context context) { super(context); getHolder().addCallback(this); }private void init(){ //加载照片 my= BitmapFactory.decodeResource(getResources(),R.drawable.my); baozha= BitmapFactory.decodeResource(getResources(),R.drawable.baozha); bg= BitmapFactory.decodeResource(getResources(),R.drawable.bg); diren= BitmapFactory.decodeResource(getResources(),R.drawable.diren); zidan= BitmapFactory.decodeResource(getResources(),R.drawable.zidan); erjihuancun=Bitmap.createBitmap(display_w,display_h, Bitmap.Config.ARGB_8888); gameImage.add(new BeijingImage(bg)); //先加入背景照片 }private interface GameImage{ public Bitmap getBitmap(); public int getX(); public int getY(); }//负责背景照片的处理 private class BeijingImage implements GameImage{ private Bitmap bg; private BeijingImage(Bitmap bg){ this.bg=bg; newBitmap = Bitmap.createBitmap(display_w,display_h, Bitmap.Config.ARGB_8888); }private Bitmap newBitmap = null; private int height = 0; public Bitmap getBitmap(){ Paint p = new Paint(); Canvas canvas = new Canvas(newBitmap); canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,height,display_w,display_h+height),p); canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,-display_h+height,display_w,height),p); height++; if(height==display_h){ height=0; } return newBitmap; }public int getX(){ return 0; }public int getY(){ return 0; } }private boolean state = false; private SurfaceHolder holder; //绘画中心 public void run() { Paint p1 = new Paint(); try{ while(true){ Canvas newCanvas = new Canvas(erjihuancun); for(GameImage image:gameImage){ newCanvas.drawBitmap(image.getBitmap(),image.getX(),image.getY(),p1); }Canvas canvas = holder.lockCanvas(); canvas.drawBitmap(erjihuancun,0,0,p1); holder.unlockCanvasAndPost(canvas); Thread.sleep(10); } }catch(Exception e){ } }@Override public void surfaceCreated(SurfaceHolder holder) { }@Override public void surfaceDestroyed(SurfaceHolder holder) { state = false; }@Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { //得到屏幕的宽和高 display_w=width; display_h=height; init(); this.holder=holder; state = true; new Thread(this).start(); }}

dafeijiView.java

文章图片

package com.example.administrator.myapplication; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; public class MainActivity extends AppCompatActivity{@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //去掉标题 // requestWindowFeature(Window.FEATURE_NO_TITLE); dafeijiGameView view =new dafeijiGameView(this); setContentView(view); }}

MainActivity.java
实现过程

使用线程绘画游戏

public void run() { Paint p1 = new Paint(); try{ while(true){ Canvas newCanvas = new Canvas(erjihuancun); for(GameImage image:gameImage){ newCanvas.drawBitmap(image.getBitmap(),image.getX(),image.getY(),p1); }Canvas canvas = holder.lockCanvas(); canvas.drawBitmap(erjihuancun,0,0,p1); holder.unlockCanvasAndPost(canvas); Thread.sleep(10); } }catch(Exception e){ } }

绘画移动的背景图片

public Bitmap getBitmap(){ Paint p = new Paint(); Canvas canvas = new Canvas(newBitmap); canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,height,display_w,display_h+height),p); canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,-display_h+height,display_w,height),p); height++; if(height==display_h){ height=0; } return newBitmap; }

surfaceCreated：创建时初始化图片并开启线程绘画游戏

@Override public void surfaceCreated(SurfaceHolder holder) { }@Override public void surfaceDestroyed(SurfaceHolder holder) { state = false; }@Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { //得到屏幕的宽和高 display_w=width; display_h=height; init(); this.holder=holder; state = true; new Thread(this).start(); }

初始化函数。加载图片

private void init(){ //加载照片 my= BitmapFactory.decodeResource(getResources(),R.drawable.my); baozha= BitmapFactory.decodeResource(getResources(),R.drawable.baozha); bg= BitmapFactory.decodeResource(getResources(),R.drawable.bg); diren= BitmapFactory.decodeResource(getResources(),R.drawable.diren); zidan= BitmapFactory.decodeResource(getResources(),R.drawable.zidan); erjihuancun=Bitmap.createBitmap(display_w,display_h, Bitmap.Config.ARGB_8888); gameImage.add(new BeijingImage(bg)); //先加入背景照片 }

线程中使用二级缓存绘画背景，每隔10ms绘画一次

Canvas canvas = holder.lockCanvas(); canvas.drawBitmap(erjihuancun,0,0,p1); holder.unlockCanvasAndPost(canvas); Thread.sleep(10);

图片坐标的移动

Paint p = new Paint(); Canvas canvas = new Canvas(newBitmap);

//第一张图片 canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,height,display_w,display_h+height),p);
//第二张图片 canvas.drawBitmap(bg, new Rect(0,0,bg.getWidth(),bg.getHeight()), new Rect(0,-display_h+height,display_w,height),p); height++;

宽度不发生改变，长度发生变化，两张图片的高不断升高(height++)

canvas.drawBitmap(bitmap, srcRect, dstRect, paint) ：在图片上绘制图片传送门
1参：要绘制的图片
2参：是对图片进行裁截，可以传null，传null则表示显示整个图片
3参：目标区域，即把原区域改变参数，得到自己想要的图片及位置，是图片在Canvas画布中显示的区域
4参：paint画笔，可以为null

Rect(left,top,right,bottom) ：用于表示坐标系中的一块矩形区域
left:左
top:上
right:右
bottom:下

if(height==display_h){ height=0; }

其实只是两张照片拼接而成，两张图片不断的向上移动。开始时，第一张在手机屏幕中间，第二张在手机屏幕下方，第一张图片超出手机最上方的范围时候拼接到第一张图片下面，下一张图片不断往上运动形成新的第一张图片在手机屏幕中间，两张背景图片就这样不断的进行循环

在MainActivity.java中添加这一句可以去掉标题