Android surfaceView之打飞机（1）

首先实现背景循环

package com.example.android.planegame;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(new PlaneView(this));
    }
}

package com.example.android.planegame;

import android.graphics.Canvas;

/**
 * Created by Administrator on 2016/7/25.
 */
public abstract class BaseDraw {
    /**
     * 绘制
     * */
    abstract void onDraw(Canvas canvas);
    /**
     * 销毁
     * */
    abstract void onDestory();
}

package com.example.android.planegame;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
 * Created by Administrator on 2016/7/25.
 */
public class PlaneView extends SurfaceView implements SurfaceHolder.Callback, Runnable {

    /**
     * 游戏是否继续
     */
    private boolean ifStop = true;

    private SurfaceHolder holder = null;
    /**
     * 画笔
     */
    private Canvas canvas = null;
    /**
     * 绘制背景用的类
     */
    private DrawBackgound drawBackgound = null;

    public PlaneView(Context context) {
        super(context);

        holder = this.getHolder();
        holder.addCallback(this);
        // 让整个界面透明
        holder.setFormat(PixelFormat.TRANSPARENT);
        setZOrderOnTop(true);

        drawBackgound = new DrawBackgound(context);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {

    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        //启动线程 开始绘制
        new Thread(this).start();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        drawBackgound.onDestory();
    }

    @Override
    public void run() {

        while (ifStop) {
            //锁定画布
            canvas = holder.lockCanvas();
            if (null != canvas) {
                //绘制背景
                try {
                    Thread.sleep(1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                drawBackgound.onDraw(canvas);
                //解锁画布并提交改变
                holder.unlockCanvasAndPost(canvas);
            }
        }
    }
}

package com.example.android.planegame;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.DisplayMetrics;
import android.util.Log;

/**
 * Created by Administrator on 2016/7/25.
 */
public class DrawBackgound extends BaseDraw {

    private Bitmap backGround = null;
    private Rect rectBp = null;
    private Rect rectBg = null;
    private Rect rectBg2 = null;
    private int screenWidth = 0;
    private int screenHeigth = 0;
    //偏移量
    private int offset = 0;

    public DrawBackgound(Context context) {

        backGround = BitmapFactory.decodeResource(context.getResources(), R.drawable.bg2);
        //未获取屏幕的宽高则获取宽高
        if (screenWidth == 0 && screenHeigth == 0) {
            Resources resources = context.getResources();
            DisplayMetrics dm = resources.getDisplayMetrics();
            screenWidth = dm.widthPixels;
            screenHeigth = dm.heightPixels;

        }

    }

    @Override
    void onDraw(Canvas canvas) {
        //判断偏移量
        if (offset >= screenHeigth) {
            offset = 0;
        } else {
            offset = offset + 1;
        }
        rectBp = new Rect(0, 0, backGround.getWidth(), backGround.getHeight());
        rectBg = new Rect(0, offset, screenWidth, screenHeigth + offset);
        rectBg2 = new Rect(0, -screenHeigth + offset, screenWidth, offset);
        canvas.drawBitmap(backGround, rectBp, rectBg, null);
        canvas.drawBitmap(backGround, rectBp, rectBg2, null);

    }

    @Override
    void onDestory() {
        backGround.recycle();
    }


}