怎么搜索网站内容,电子商务网站开发系统平台,外贸公司有哪些类型,手机系统网站SurfaceView也是继承了View#xff0c;但是我们并不需要去实现它的draw方法来绘制自己#xff0c;为什么呢#xff1f; 因为它和View有一个很大的区别#xff0c;View在UI线程去更新自己#xff1b;而SurfaceView则在一个子线程中去更新自己#xff1b;这也显示出了它的… SurfaceView也是继承了View但是我们并不需要去实现它的draw方法来绘制自己为什么呢 因为它和View有一个很大的区别View在UI线程去更新自己而SurfaceView则在一个子线程中去更新自己这也显示出了它的优势当制作游戏等需要不断刷新View时因为是在子线程避免了对UI线程的阻塞。 知道了优势以后你会想那么不使用draw方法哪来的canvas使用呢 大家都记得更新View的时候draw方法提供了一个canvasSurfaceView内部内嵌了一个专门用于绘制的Surface而这个Surface中包含一个Canvas。 有了Canvas我们如何获取呢 SurfaceView里面有个getHolder方法我们可以获取一个SurfaceHolder。通过SurfaceHolder可以监听SurfaceView的生命周期以及获取Canvas对象。 通常用法 public class SurfaceViewTemplate extends SurfaceView implements Callback, Runnable
{private SurfaceHolder mHolder;/*** 与SurfaceHolder绑定的Canvas*/private Canvas mCanvas;/*** 用于绘制的线程*/private Thread t;/*** 线程的控制开关*/private boolean isRunning;public SurfaceViewTemplate(Context context){this(context, null);}public SurfaceViewTemplate(Context context, AttributeSet attrs){super(context, attrs);mHolder getHolder();mHolder.addCallback(this);// setZOrderOnTop(true);// 设置画布 背景透明// mHolder.setFormat(PixelFormat.TRANSLUCENT);//设置可获得焦点setFocusable(true);setFocusableInTouchMode(true);//设置常亮this.setKeepScreenOn(true);}Overridepublic void surfaceCreated(SurfaceHolder holder){// 开启线程isRunning true;t new Thread(this);t.start();}Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height){// TODO Auto-generated method stub}Overridepublic void surfaceDestroyed(SurfaceHolder holder){// 通知关闭线程isRunning false;}Overridepublic void run(){// 不断的进行drawwhile (isRunning){draw();}}private void draw(){try{// 获得canvasmCanvas mHolder.lockCanvas();if (mCanvas ! null){// drawSomething..}} catch (Exception e){} finally{if (mCanvas ! null)mHolder.unlockCanvasAndPost(mCanvas);}}
} 结合上面我们的介绍我们在构造中通过getHolder拿到SurfaceHolder对象然后设置一个addCallback回调去监听SurfaceView的生命周期生命周期有三个方法分别为create,change,destory;我们一般在create里面进行初始化的一些操作然后开启线程在destroy里面设置关闭线程 所有的绘制流程都是线程的run方法里面可以看到我们的draw方法。 注意下我们在draw里面进行了try catch然后很多的判空主要是因为当用户点击back或者按下home键以后surfaceview会被销毁 mHolder.lockCanvas();返回的就是null了所以为了避免造成空指针错误我们各种判null甚至还加了个try catch。 实例 抽奖转盘 效果图 代码如下 package com.zhy.view;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;import com.zhy.demo_zhy_06_choujiangzhuanpan.R;public class LuckyPanView extends SurfaceView implements Callback, Runnable
{private SurfaceHolder mHolder;/*** 与SurfaceHolder绑定的Canvas*/private Canvas mCanvas;/*** 用于绘制的线程*/private Thread t;/*** 线程的控制开关*/private boolean isRunning;/*** 抽奖的文字*/private String[] mStrs new String[] { 单反相机, IPAD, 恭喜发财, IPHONE,妹子一只, 恭喜发财 };/*** 每个盘块的颜色*/private int[] mColors new int[] { 0xFFFFC300, 0xFFF17E01, 0xFFFFC300,0xFFF17E01, 0xFFFFC300, 0xFFF17E01 };/*** 与文字对应的图片*/private int[] mImgs new int[] { R.drawable.danfan, R.drawable.ipad,R.drawable.f040, R.drawable.iphone, R.drawable.meizi,R.drawable.f040 };/*** 与文字对应图片的bitmap数组*/private Bitmap[] mImgsBitmap;/*** 盘块的个数*/private int mItemCount 6;/*** 绘制盘块的范围*/private RectF mRange new RectF();/*** 圆的直径*/private int mRadius;/*** 绘制盘快的画笔*/private Paint mArcPaint;/*** 绘制文字的画笔*/private Paint mTextPaint;/*** 滚动的速度*/private double mSpeed;private volatile float mStartAngle 0;/*** 是否点击了停止*/private boolean isShouldEnd;/*** 控件的中心位置*/private int mCenter;/*** 控件的padding这里我们认为4个padding的值一致以paddingleft为标准*/private int mPadding;/*** 背景图的bitmap*/private Bitmap mBgBitmap BitmapFactory.decodeResource(getResources(),R.drawable.bg2);/*** 文字的大小*/private float mTextSize TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 20, getResources().getDisplayMetrics());public LuckyPanView(Context context){this(context, null);}public LuckyPanView(Context context, AttributeSet attrs){super(context, attrs);mHolder getHolder();mHolder.addCallback(this);// setZOrderOnTop(true);// 设置画布 背景透明// mHolder.setFormat(PixelFormat.TRANSLUCENT);setFocusable(true);setFocusableInTouchMode(true);this.setKeepScreenOn(true);}/*** 设置控件为正方形*/Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){super.onMeasure(widthMeasureSpec, heightMeasureSpec);int width Math.min(getMeasuredWidth(), getMeasuredHeight());// 获取圆形的直径mRadius width - getPaddingLeft() - getPaddingRight();// padding值mPadding getPaddingLeft();// 中心点mCenter width / 2;setMeasuredDimension(width, width);}Overridepublic void surfaceCreated(SurfaceHolder holder){// 初始化绘制圆弧的画笔mArcPaint new Paint();mArcPaint.setAntiAlias(true);mArcPaint.setDither(true);// 初始化绘制文字的画笔mTextPaint new Paint();mTextPaint.setColor(0xFFffffff);mTextPaint.setTextSize(mTextSize);// 圆弧的绘制范围mRange new RectF(getPaddingLeft(), getPaddingLeft(), mRadius getPaddingLeft(), mRadius getPaddingLeft());// 初始化图片mImgsBitmap new Bitmap[mItemCount];for (int i 0; i mItemCount; i){mImgsBitmap[i] BitmapFactory.decodeResource(getResources(),mImgs[i]);}// 开启线程isRunning true;t new Thread(this);t.start();}Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height){// TODO Auto-generated method stub}Overridepublic void surfaceDestroyed(SurfaceHolder holder){// 通知关闭线程isRunning false;}Overridepublic void run(){// 不断的进行drawwhile (isRunning){long start System.currentTimeMillis();draw();long end System.currentTimeMillis();try{if (end - start 50){Thread.sleep(50 - (end - start));}} catch (InterruptedException e){e.printStackTrace();}}}private void draw(){try{// 获得canvasmCanvas mHolder.lockCanvas();if (mCanvas ! null){// 绘制背景图drawBg();/*** 绘制每个块块每个块块上的文本每个块块上的图片*/float tmpAngle mStartAngle;float sweepAngle (float) (360 / mItemCount);for (int i 0; i mItemCount; i){// 绘制快快mArcPaint.setColor(mColors[i]);
// mArcPaint.setStyle(Style.STROKE);mCanvas.drawArc(mRange, tmpAngle, sweepAngle, true,mArcPaint);// 绘制文本drawText(tmpAngle, sweepAngle, mStrs[i]);// 绘制IcondrawIcon(tmpAngle, i);tmpAngle sweepAngle;}// 如果mSpeed不等于0则相当于在滚动mStartAngle mSpeed;// 点击停止时设置mSpeed为递减为0值转盘停止if (isShouldEnd){mSpeed - 1;}if (mSpeed 0){mSpeed 0;isShouldEnd false;}// 根据当前旋转的mStartAngle计算当前滚动到的区域calInExactArea(mStartAngle);}} catch (Exception e){e.printStackTrace();} finally{if (mCanvas ! null)mHolder.unlockCanvasAndPost(mCanvas);}}/*** 根据当前旋转的mStartAngle计算当前滚动到的区域 绘制背景不重要完全为了美观*/private void drawBg(){mCanvas.drawColor(0xFFFFFFFF);mCanvas.drawBitmap(mBgBitmap, null, new Rect(mPadding / 2,mPadding / 2, getMeasuredWidth() - mPadding / 2,getMeasuredWidth() - mPadding / 2), null);}/*** 根据当前旋转的mStartAngle计算当前滚动到的区域* * param startAngle*/public void calInExactArea(float startAngle){// 让指针从水平向右开始计算float rotate startAngle 90;rotate % 360.0;for (int i 0; i mItemCount; i){// 每个的中奖范围float from 360 - (i 1) * (360 / mItemCount);float to from 360 - (i) * (360 / mItemCount);if ((rotate from) (rotate to)){Log.d(TAG, mStrs[i]);return;}}}/*** 绘制图片* * param startAngle* param sweepAngle* param i*/private void drawIcon(float startAngle, int i){// 设置图片的宽度为直径的1/8int imgWidth mRadius / 8;float angle (float) ((30 startAngle) * (Math.PI / 180));int x (int) (mCenter mRadius / 2 / 2 * Math.cos(angle));int y (int) (mCenter mRadius / 2 / 2 * Math.sin(angle));// 确定绘制图片的位置Rect rect new Rect(x - imgWidth / 2, y - imgWidth / 2, x imgWidth/ 2, y imgWidth / 2);mCanvas.drawBitmap(mImgsBitmap[i], null, rect, null);}/*** 绘制文本* * param rect* param startAngle* param sweepAngle* param string*/private void drawText(float startAngle, float sweepAngle, String string){Path path new Path();path.addArc(mRange, startAngle, sweepAngle);float textWidth mTextPaint.measureText(string);// 利用水平偏移让文字居中float hOffset (float) (mRadius * Math.PI / mItemCount / 2 - textWidth / 2);// 水平偏移float vOffset mRadius / 2 / 6;// 垂直偏移mCanvas.drawTextOnPath(string, path, hOffset, vOffset, mTextPaint);}/*** 点击开始旋转* * param luckyIndex*/public void luckyStart(int luckyIndex){// 每项角度大小float angle (float) (360 / mItemCount);// 中奖角度范围因为指针向上所以水平第一项旋转到指针指向需要旋转210-270float from 270 - (luckyIndex 1) * angle;float to from angle;// 停下来时旋转的距离float targetFrom 4 * 360 from;/*** pre* (v1 0) * (v11) / 2 target ;* v1*v1 v1 - 2target 0 ;* v1-1(1*1 8 *1 * target)/2;* /pre*/float v1 (float) (Math.sqrt(1 * 1 8 * 1 * targetFrom) - 1) / 2;float targetTo 4 * 360 to;float v2 (float) (Math.sqrt(1 * 1 8 * 1 * targetTo) - 1) / 2;mSpeed (float) (v1 Math.random() * (v2 - v1));isShouldEnd false;}public void luckyEnd(){mStartAngle 0;isShouldEnd true;}public boolean isStart(){return mSpeed ! 0;}public boolean isShouldEnd(){return isShouldEnd;}}代码下载 源代码 参考链接 Android SurfaceView实战 打造抽奖转盘 - Hongyang - 博客频道 - CSDN.NET 实战 flabby bird 效果图 分析 仔细观察游戏需要绘制的有背景、地板、鸟、管道、分数 游戏开始时 地板给人一种想左移动的感觉 管道与地板同样的速度向左移动 鸟默认下落 当用户touch屏幕时鸟上升一段距离后下落 运动过程中需要判断管道和鸟之间的位置关系是否触碰是否穿过等需要计算分数。 可以分为 piple类bird类floor类Game类等来实现 GameFlabbyBird类代码 package com.zhy.view;import java.util.ArrayList;
import java.util.List;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;import com.zhy.surfaceViewDemo.R;public class GameFlabbyBird extends SurfaceView implements Callback, Runnable
{private SurfaceHolder mHolder;/*** 与SurfaceHolder绑定的Canvas*/private Canvas mCanvas;/*** 用于绘制的线程*/private Thread t;/*** 线程的控制开关*/private boolean isRunning;private Paint mPaint;/*** 当前View的尺寸*/private int mWidth;private int mHeight;private RectF mGamePanelRect new RectF();/*** 背景*/private Bitmap mBg;/*** *********鸟相关***********************/private Bird mBird;private Bitmap mBirdBitmap;/*** 地板*/private Floor mFloor;private Bitmap mFloorBg;/*** *********管道相关***********************//*** 管道*/private Bitmap mPipeTop;private Bitmap mPipeBottom;private RectF mPipeRect;private int mPipeWidth;/*** 管道的宽度 60dp*/private static final int PIPE_WIDTH 60;private ListPipe mPipes new ArrayListPipe();/*** 分数*/private final int[] mNums new int[] { R.drawable.n0, R.drawable.n1,R.drawable.n2, R.drawable.n3, R.drawable.n4, R.drawable.n5,R.drawable.n6, R.drawable.n7, R.drawable.n8, R.drawable.n9 };private Bitmap[] mNumBitmap;private int mGrade 0;private int mRemovedPipe 0;private static final float RADIO_SINGLE_NUM_HEIGHT 1 / 15f;private int mSingleGradeWidth;private int mSingleGradeHeight;private RectF mSingleNumRectF;private int mSpeed Util.dp2px(getContext(), 2);/***********************************/private enum GameStatus{WAITTING, RUNNING, STOP;}/*** 记录游戏的状态*/private GameStatus mStatus GameStatus.WAITTING;/*** 触摸上升的距离因为是上升所以为负值*/private static final int TOUCH_UP_SIZE -16;/*** 将上升的距离转化为px这里多存储一个变量变量在run中计算* */private final int mBirdUpDis Util.dp2px(getContext(), TOUCH_UP_SIZE);private int mTmpBirdDis;/*** 鸟自动下落的距离*/private final int mAutoDownSpeed Util.dp2px(getContext(), 2);/*** 两个管道间距离*/private final int PIPE_DIS_BETWEEN_TWO Util.dp2px(getContext(), 300);/*** 记录移动的距离达到 PIPE_DIS_BETWEEN_TWO 则生成一个管道*/private int mTmpMoveDistance;/*** 记录需要移除的管道*/private ListPipe mNeedRemovePipe new ArrayListPipe();/*** 处理一些逻辑上的计算*/private void logic(){switch (mStatus){case RUNNING:mGrade 0;// 更新我们地板绘制的x坐标地板移动mFloor.setX(mFloor.getX() - mSpeed);logicPipe();// 默认下落点击时瞬间上升mTmpBirdDis mAutoDownSpeed;mBird.setY(mBird.getY() mTmpBirdDis);// 计算分数mGrade mRemovedPipe;for (Pipe pipe : mPipes){if (pipe.getX() mPipeWidth mBird.getX()){mGrade;}}checkGameOver();break;case STOP: // 鸟落下// 如果鸟还在空中先让它掉下来if (mBird.getY() mFloor.getY() - mBird.getWidth()){mTmpBirdDis mAutoDownSpeed;mBird.setY(mBird.getY() mTmpBirdDis);} else{mStatus GameStatus.WAITTING;initPos();}break;default:break;}}/*** 重置鸟的位置等数据*/private void initPos(){mPipes.clear();//立即增加一个mPipes.add(new Pipe(getContext(), getWidth(), getHeight(), mPipeTop,mPipeBottom));mNeedRemovePipe.clear();// 重置鸟的位置// mBird.setY(mHeight * 2 / 3);mBird.resetHeigt();// 重置下落速度mTmpBirdDis 0;mTmpMoveDistance 0 ;mRemovedPipe 0;}private void checkGameOver(){// 如果触碰地板ggif (mBird.getY() mFloor.getY() - mBird.getHeight()){mStatus GameStatus.STOP;}// 如果撞到管道for (Pipe wall : mPipes){// 已经穿过的if (wall.getX() mPipeWidth mBird.getX()){continue;}if (wall.touchBird(mBird)){mStatus GameStatus.STOP;break;}}}private void logicPipe(){// 管道移动for (Pipe pipe : mPipes){if (pipe.getX() -mPipeWidth){mNeedRemovePipe.add(pipe);mRemovedPipe;continue;}pipe.setX(pipe.getX() - mSpeed);}// 移除管道mPipes.removeAll(mNeedRemovePipe);mNeedRemovePipe.clear();// Log.e(TAG, 现存管道数量 mPipes.size());// 管道mTmpMoveDistance mSpeed;// 生成一个管道if (mTmpMoveDistance PIPE_DIS_BETWEEN_TWO){Pipe pipe new Pipe(getContext(), getWidth(), getHeight(),mPipeTop, mPipeBottom);mPipes.add(pipe);mTmpMoveDistance 0;}}Overridepublic boolean onTouchEvent(MotionEvent event){int action event.getAction();if (action MotionEvent.ACTION_DOWN){switch (mStatus){case WAITTING:mStatus GameStatus.RUNNING;break;case RUNNING:mTmpBirdDis mBirdUpDis;break;}}return true;}public GameFlabbyBird(Context context){this(context, null);}public GameFlabbyBird(Context context, AttributeSet attrs){super(context, attrs);mHolder getHolder();mHolder.addCallback(this);setZOrderOnTop(true);// 设置画布 背景透明mHolder.setFormat(PixelFormat.TRANSLUCENT);// 设置可获得焦点setFocusable(true);setFocusableInTouchMode(true);// 设置常亮this.setKeepScreenOn(true);mPaint new Paint();mPaint.setAntiAlias(true);mPaint.setDither(true);initBitmaps();// 初始化速度// mSpeed Util.dp2px(getContext(), 2);mPipeWidth Util.dp2px(getContext(), PIPE_WIDTH);}/*** 初始化图片*/private void initBitmaps(){mBg loadImageByResId(R.drawable.bg1);mBirdBitmap loadImageByResId(R.drawable.b1);mFloorBg loadImageByResId(R.drawable.floor_bg2);mPipeTop loadImageByResId(R.drawable.g2);mPipeBottom loadImageByResId(R.drawable.g1);mNumBitmap new Bitmap[mNums.length];for (int i 0; i mNumBitmap.length; i){mNumBitmap[i] loadImageByResId(mNums[i]);}}Overridepublic void surfaceCreated(SurfaceHolder holder){Log.e(TAG, surfaceCreated);// 开启线程isRunning true;t new Thread(this);t.start();}Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height){Log.e(TAG, surfaceChanged);// TODO Auto-generated method stub}Overridepublic void surfaceDestroyed(SurfaceHolder holder){Log.e(TAG, surfaceDestroyed);// 通知关闭线程isRunning false;}Overridepublic void run(){while (isRunning){long start System.currentTimeMillis();logic();draw();long end System.currentTimeMillis();try{if (end - start 50){Thread.sleep(50 - (end - start));}} catch (InterruptedException e){e.printStackTrace();}}}private void draw(){try{// 获得canvasmCanvas mHolder.lockCanvas();if (mCanvas ! null){// drawSomething..drawBg();drawBird();drawPipes();drawFloor();drawGrades();}} catch (Exception e){} finally{if (mCanvas ! null)mHolder.unlockCanvasAndPost(mCanvas);}}private void drawFloor(){mFloor.draw(mCanvas, mPaint);}/*** 绘制背景*/private void drawBg(){mCanvas.drawBitmap(mBg, null, mGamePanelRect, null);}private void drawBird(){mBird.draw(mCanvas);}/*** 绘制管道*/private void drawPipes(){for (Pipe pipe : mPipes){// pipe.setX(pipe.getX() - mSpeed);pipe.draw(mCanvas, mPipeRect);}}/*** 初始化尺寸相关*/Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh){super.onSizeChanged(w, h, oldw, oldh);mWidth w;mHeight h;mGamePanelRect.set(0, 0, w, h);// 初始化mBirdmBird new Bird(getContext(), mWidth, mHeight, mBirdBitmap);// 初始化地板mFloor new Floor(mWidth, mHeight, mFloorBg);// 初始化管道范围mPipeRect new RectF(0, 0, mPipeWidth, mHeight);Pipe pipe new Pipe(getContext(), w, h, mPipeTop, mPipeBottom);mPipes.add(pipe);// 初始化分数mSingleGradeHeight (int) (h * RADIO_SINGLE_NUM_HEIGHT);mSingleGradeWidth (int) (mSingleGradeHeight * 1.0f/ mNumBitmap[0].getHeight() * mNumBitmap[0].getWidth());mSingleNumRectF new RectF(0, 0, mSingleGradeWidth, mSingleGradeHeight);}/*** 绘制分数*/private void drawGrades(){String grade mGrade ;mCanvas.save(Canvas.MATRIX_SAVE_FLAG);mCanvas.translate(mWidth / 2 - grade.length() * mSingleGradeWidth / 2,1f / 8 * mHeight);// draw single num one by onefor (int i 0; i grade.length(); i){String numStr grade.substring(i, i 1);int num Integer.valueOf(numStr);mCanvas.drawBitmap(mNumBitmap[num], null, mSingleNumRectF, null);mCanvas.translate(mSingleGradeWidth, 0);}mCanvas.restore();}/*** 根据resId加载图片* * param resId* return*/private Bitmap loadImageByResId(int resId){return BitmapFactory.decodeResource(getResources(), resId);}
} MainActivity代码 package com.zhy.surfaceViewDemo;import com.zhy.view.GameFlabbyBird;import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;public class MainActivity extends Activity
{GameFlabbyBird mGame;Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);requestWindowFeature(Window.FEATURE_NO_TITLE);mGame new GameFlabbyBird(this);setContentView(mGame);}}代码下载 代码下载 参考链接 Android SurfaceView实战 带你玩转flabby bird 上 - Hongyang - 博客频道 - CSDN.NET Android SurfaceView实战 带你玩转flabby bird 下 - Hongyang - 博客频道 - CSDN.NET 转载于:https://www.cnblogs.com/jjx2013/p/6223641.html
