简单的贪吃蛇源码分析

念和操作方式。具体细节先卖一个关子，作品准备参加这次第二届大学生android应用开Snake*TileView是基于AndroidView类实现的方块图类，用来支撑上层类的调用，绘制方块图的显示界面。通过这些代码，能打之了解如何扩展View*SnakeViewTileView，实现了游戏逻辑和具体的*SnakeActivity类。PS:android2.2下左右按键操作，现在大多数android机是没有方向键的吧。[java]view</pre><p></p><p><strong></strong></p><prename="code"class="java">packagecom.example.android.snake;importimportimportimportimportimportimportimport*TileView:aView-variantdesignedforhandlingarraysof"icons"or**publicclassTileViewextendsView{*Parameterscontrollingthesizeofthetilesandtheirrangewithin*Width/Heightareinpixels,andDrawableswillbescaledtofitto*dimensions.X/YTileCountsarethenumberoftilesthatwillbeprotectedstaticintmTileSizetileprotectedstaticintmXTileCountX量protectedstaticintmYTileCount;//Y量privatestaticintmXOffsetpixelprivatestaticint*Ahashthatmapsintegerhandlesspecifiedbythesubclasserto*drawablethatwillbeusedforthat*着不同种类的bitmap图。通过resetTiles，loadTile，将游戏中* privateBitmap[]mTileArray;*Adimensionalarrayofintegersinwhichthenumberrepresents*indexofthetilethatshouldbedrawnatthat*整个界面内每个tile位置应该绘制的tile**setTile、clearTile*privateint[][]mTileGrid;privatefinalPaintmPaint=newPaint();publicTileView(Contextcontext,AttributeSetattrs,intdefStyle)super(context,attrs,tileSize。参考： TypedArraya=context.obtainStyledAttributes(attrs,R.styleable.TileVimTileSize=a.getInt(R.styleable.TileView_tileSize, publicTileView(Contextcontext,AttributeSetattrs)super(context, TypedArraya=context.obtainStyledAttributes(attrs,R.styleable.TileVimTileSize=a.getInt(R.styleable.TileView_tileSize, *ReststheinternalarrayofBitmapsusedfordrawingtiles,*setstheumindexoftilestobe*重置mTileArray，在游戏初始的时候使用**@parampublicvoidresetTiles(inttilecount)mTileArray=new protectedvoidonSizeChanged(intw,inth,intoldw,intoldh)mXTileCount=(int)Math.floor(w/mYTileCount=(int)Math.floor(h/mTileSize);//mXOffsetmYOffsetmXOffset=((w-(mTileSize*mXTileCount))/mYOffset=((h-(mTileSize*mYTileCount))/2);mTileGrid=new *FunctiontosetthespecifiedDrawableasthetilefora*integer*加载具体的砖块到砖块字典*即将对应的砖块的对应的加载到mTileArray数组*@param*@parampublicvoidloadTile(intkey,Drawabletile)//Drawablebitmap的转换。由于外部程序使用的//drawable格式，而我们的数组是bitmap格式，方便最终的绘bitmap的转换。Bitmapbitmap=Bitmap.createBitmap(mTileSize,mTileSize,BitmCanvascanvas=newtile.setBounds(0,0,mTileSize,mTileArray[key]= *Usedtoindicatethataparticulartile(setwithloadTileandreferen*byaninteger)shouldbedrawnatthegivenx/ycoordinatesduring*nextinvalidate/draw**@param*@param*@parampublicvoidsetTile(inttileindex,intx,inty)mTileGrid[x][y]=}*Resetsalltilesto0***setTile()publicvoidclearTiles()for(intx=0;x<mXTileCount;x++)for(inty=0;y<mYTileCount;y++)setTile(0,x, *@seepublicvoidonDraw(Canvascanvas)for(intx=0;x<mXTileCount;x+=1)for(inty=0;y<mYTileCount;y+=1)if(mTileGrid[x][y]>0)mXOffset+x*mYOffset+y*}}}}}[java]viewpackageimportimportimportimportimportimportimportimportimportimportimportimport*SnakeView:implementationofasimplegameofpublicclassSnakeViewextendsTileView{ privatestaticfinalStringTAG="SnakeView"; *Currentmodeofapplication:READYtorun,RUNNING,oryouhaveal*lost.staticfinalintsareusedinsteadofanenumfor*privateintmMode=publicstaticfinalintPAUSE0;//publicstaticfinalintREADY1;//publicstaticfinalintRUNNING2;//publicstaticfinalintLOSE3;//结束,输了游戏*Currentdirectionthesnakeis*privateintmDirection=privateintmNextDirection=privatestaticfinalintNORTH=privatestaticfinalintSOUTH=privatestaticfinalintEAST=privatestaticfinalintWEST=4;*LabelsforthedrawablesthatwillbeloadedintotheTileView*privatestaticfinalintRED_STAR=privatestaticfinalintYELLOW_STAR=privatestaticfinalintGREEN_STAR=3; *mScore:usedtotrackthenumberofapplescapturedmMoveDelay:numberof *millisecondsbetweensnakemovements.Thiswilldecreaseasapples*privatelongmScore0;// privatelongmMoveDelay600;//每移动一步的延时。初始时设置为600ms9折 *mLastMove:trackstheabsolutetimewhenthesnakelastmoved,andisused*todetermineifamoveshouldbemadebasedon*privatelongmLastMove;*mStatusText:textshowstotheuserinsomerun*privateTextViewmStatusText;*mSnakeTrail:alistofCoordinatesthatmakeupthesnake's*mAppleList:thesecretlocationofthejuicyapplesthesnake*两个链表，分别用来蛇体和果子的坐标 *每次蛇体的运动，蛇体的增长，产生新的苹果，被苹果，都会在这privateArrayList<Coordinate>mSnakeTrail=newprivateArrayList<Coordinate>mAppleList=new*EveryoneneedsalittlerandomnessintheirprivatestaticfinalRandomRNG=new*Createasimplehandlerthatwecanusetocauseanimationto*setourselvesasatargetandwecanusethe*functiontocauseanupdate/invalidatetooccuratalater*Handler*Handlerandroid的线程模型（注意privateRefreshHandlermRedrawHandler=newRefreshHandler(); classRefreshHandlerextendsHandler{//publicvoidhandleMessage(Messagemsg) //定时发送消息给UIpublicvoidsleep(longdelayMillis)this.removeMessages(0清空消息队列，Handler进入对新消sendMessageDelayed(obtainMessage(0delayMillis定时发送新消息,激活handler}publicSnakeView(Contextcontext,AttributeSetattrs)super(context,initSnakeView();//构造函数中，别忘了，初始化游戏 publicSnakeView(Contextcontext,AttributeSetattrs,intdefStyle)super(context,attrs, privatevoidinitSnakeView()setFocusable(truefocus是不可或缺的。Resourcesr=loadTile(RED_STAR,loadTile(YELLOW_STAR,}privatevoidinitNewGame()//Fornowwe'rejustgoingtoloadupashortdefaulteastbound//that'sjustturnedmSnakeTrail.add(newCoordinate(7,mSnakeTrail.add(newCoordinate(6,mSnakeTrail.add(newCoordinate(5,mSnakeTrail.add(newCoordinate(4,mSnakeTrail.add(newCoordinate(3,mSnakeTrail.add(newCoordinate(2,mNextDirection=//TwoapplestostartmMoveDelay=mScore=}*GivenaArrayListofcoordinates,weneedtoflattenthemintoanarrayof*intsbeforewecanstuffthemintoamapforflatteningand**@paramcvec:aArrayListofCoordinate*@return:asimplearraycontainingthex/yvaluesofthecoordinat*asx1,y1,x2,y2,x3,y3...*Bundle*所以需要将我们的部分数据结构，如蛇体和苹果位置的数组，转换int数组。privateint[]coordArrayListToArray(ArrayList<Coordinate>cvec)intcount=int[]rawArray=newint[count*for(intindex=0;index<count;index++)Coordinatec=rawArray[2*index]=rawArray[2*index+1]=}return}*Savegamestatesothattheuserdoesnotlose*ifthegameprocessiskilledwhilewearein* *@returnaBundlewiththisview'spublicBundlesaveState()Bundlemap=newBundle();map.putInt("mDirection",map.putLong("mScore",map.putIntArray("mSnakeTrail",coordArrayListToArray(mSnakeTrreturn *Givenaflattenedarrayofordinatepairs,wereconstitutetheminto*ArrayListofCoordinate*@paramrawArray:*@returnaArrayListof{ArrayList<Coordinate>coordArrayList=newArrayList<CoordinatintcoordCount=for(intindex=0;index<coordCount;index+=2)Coordinatec=newCoordinate(rawArray[index],rawArray[index+1]); return *Restoregamestateifourprocessisbeing*@paramicicleaBundlecontainingthegamepublicvoidrestoreState(Bundleicicle)mAppleList=coordArrayToArrayList(icicle.getIntArray("mAppleLismDirection=mNextDirection=mMoveDelay=mScore=mSnakeTrail=coordArrayToArrayList(icicle.getIntArray("mSnake}*handleskeyeventsinthegame.Updatethedirectionoursnake*basedontheDPAD.Ignoreeventsthatwouldcausethesnaketoi*turnbackon*按键的*现在大多数的android都没有按键了**@seeandroid.view.View#onKeyDown(int,publicbooleanonKeyDown(intkeyCode,KeyEventmsg)if(keyCode==KeyEvent.KEYCODE_DPAD_UP)if(mMode==READY|mMode==LOSE)*Atthebeginningofthegame,ortheendofaprevious*weshouldstartanew();//return}if(mMode==PAUSE) *Ifthegameismerelypaused,weshouldjustcontinuewhe*weleftreturn} ifmDirectionSOUTH){//mNextDirection=}return}if(keyCode==KeyEvent.KEYCODE_DPAD_DOWN)if(mDirection!=NORTH)mNextDirection= return if(keyCode==KeyEvent.KEYCODE_DPAD_LEFT)if(mDirection!=EAST)mNextDirection= return if(keyCode==KeyEvent.KEYCODE_DPAD_RIGHT)if(mDirection!=WEST)mNextDirection= return}returnsuper.onKeyDown(keyCode,}*SetstheTextViewthatwillbeusedtogiveinformation(suchas"G*Over"tothe*起初不明白这个方法有什么作用。删除了以后才发现错误。Snaketextview.publicvoidsetTextView(TextViewnewView)mStatusText=}*Updatesthecurrentmodeoftheapplication(RUNNINGorEDorthe*aswellassetsthevisibilityoftextviewfor**@parampublicvoidsetMode(intnewMode)intoldMode=mMode=if(newMode==RUNNING&oldMode!=RUNNING));//updateinitGame中也有update(),不过放心～update不会影响效果的，//mLastMovemMoveDelay来校验。这会Update()中体现。//update()似乎不会影响结 Resourcesres=CharSequencestr=if(newMode==PAUSE)str= if(newMode==READY)str= if(newMode==LOSE)str=res.getString(R.string.mode_lose_prefix)+ + *Selectsarandomlocationwithinthegardenthatisnotcurrentlyco*bythesnake.Currently_could_gointoaninfiniteloopifthe*currentlyfillsthegarden,butwe'llleavediscoveryofthisprizeto*trulyexcellentsnake-*在地图上随机的增加果子。注意苹果的位置不可以是蛇体所在噢～这里有个小bug，没有检测**新产生的果子的坐标会增加到mApplistprivatevoidaddRandomApple()CoordinatenewCoord=booleanfound=while(!found)//ChooseanewlocationforourintnewX=1+RNG.nextInt(mXTileCount-intnewY=1+RNG.nextInt(mYTileCount-newCoord=newCoordinate(newX,newY);//Makesureit'snotalreadyunderthebooleancollision=intsnakelength=for(intindex=0;index<snakelength;index++)collision= //ifwe'rehereandthere'sbeennocollision,thenwe//agoodlocationforanapple.Otherwise,we'llcircle//andtryfound= if(newCoord==null)Log.e(TAG,"Somehowendedupwithanull *Handlesthebasicupdateloop,checkingtoseeifweareintherun*state,determiningifamoveshouldbemade,updatingthesnake's*刷新游戏状态。每次游戏画面的更新、游戏数据的更新，都是依靠update()来完成的。publicvoidupdate()if(mMode==RUNNING)longnow=System.currentTimeMillis();ifnowmLastMovemMoveDelay){////mMode变化时，对update()正 updateApples();//mLastMove= mRedrawHandler.sleep(mMoveDelay);//Handler *Drawssome*setTileprivatevoidupdateWalls()for(intx=0;x<mXTileCount;x++)setTile(GREEN_STAR,x,setTile(GREEN_STAR,x,mYTileCount- for(inty=1;y<mYTileCount-1;y++) setTile(GREEN_STAR,0, setTile(GREEN_STAR,mXTileCount-1, *Drawssome*privatevoidupdateApples()for(Coordinatec:mAppleList)setTile(YELLOW_STAR,c.x, *Figureoutwhichwaythesnakeisgoing,seeifhe'srunintoanything(the *walls,himself,oranapple).Ifhe'snotgoingtodie,wethenaddto *frontandsubtractfromtherearinordertosimulatemotion.Ifwewantto*growhim,wedon'tsubtractfromthe*privatevoidupdateSnake()booleangrowSnakefalse;////grabthesnakebytheCoordinateheadmSnakeTrail.get(0);//头部很重要，只有头部CoordinatenewHeadnewCoordinate(11蛇下一步一定会前移，也就试newHead。长长只会从尾部增加。//CoordinatenewHead呢？反正肯定会给//switch语句中给mDirection=mNextDirection; switch(mDirection) caseEAST: newHead=newCoordinate(head.x+1, caseWEST: newHead=newCoordinate(head.x-1, caseNORTH: newHead=newCoordinate(head.x,head.y- caseSOUTH: newHead=newCoordinate(head.x,head.y+ //Collision//Fornowwehavea1-squarewallaroundtheentire//if((newHead.x<1)||(newHead.y<1)||(newHead.x>mXTileCount-2)||(newHead.y>mYTileCount-2)) //Lookforcollisionswith//intsnakelength={for(intsnakeindex=0;snakeindex<snakelength;Coordinatec=if(c.equals(newHead))}}//Lookfor//intapplecount=for(intappleindex=0;appleindex<applecount;appleindex++)Coordinatec=if(c.equals(newHead))mMoveDelay*=growSnake=}}//pushanewheadontotheArrayListandpulloffthe//mSnakeTrail.add(0,//exceptifwewantthesnaketoif(!growSnake)}//intindex=for(Coordinatec:mSnakeTrail)if(index==0)setTile(YELLOW_STAR,c.x,}elsesetTile(RED_STAR,c.x,}}}*Simpleclasscontaining