android涂鴉版手寫版代碼

1、一、概述這次要做一個(gè)簡(jiǎn)單的涂鴉板應(yīng)用，以前在Qt上實(shí)現(xiàn)過(guò)，突然想到要把它在Android上實(shí)現(xiàn)，呵呵，既簡(jiǎn)單又有趣。二、實(shí)現(xiàn)新建工程MyWall,修改/res/layout/main.xml文件，在里面添加一個(gè)SurfaceView和兩個(gè)Button,用到了RelativeLayout布局，完整的main.xml文件如下：123891617 LinearLayout18 android:id=+id/line19 android:layout_width=fill_parent20 android:layout_height=wrap_content21 android:layout_alig

2、nParentBottom=trueAndroid開(kāi)發(fā)實(shí)例篇（1）簡(jiǎn)易涂鴉板232431323940復(fù)制代碼接著，修改MyWallActivity.java文件，最主要是覆寫了onTouchEvent()函數(shù)，在這個(gè)函數(shù)里過(guò)濾出觸屏拖動(dòng)事件，然后獲取其相應(yīng)的坐標(biāo)和畫線，關(guān)于SurfaceView的用法在基礎(chǔ)篇里有講到。完整的內(nèi)容如下：1packagecom.nan.wall;23importandroid.app.Activity;4importandroid.app.AlertDialog;5importandroid.app.Dialog;6importandroid.content.Di

3、alogInterface;7importandroid.graphics.Canvas;8importandroid.graphics.Color;9importandroid.graphics.Paint;10 importandroid.graphics.Rect;11 importandroid.os.Bundle;privateintwhichColor=0;32/*Calledwhentheactivityisfirstcreated.*/mSurfaceHolder=mSurfaceView.getHolder();42mPaint.setC010r(Color.RED);mPa

4、int.setStrokeWidth(2.0f);12importandroid.view.MotionEvent;13importandroid.view.SurfaceHolder;14importandroid.view.SurfaceView;15importandroid.view.View;16importandroid.widget.Button;1718publicclassMyWallActivityextendsActivity20privateSurfaceViewmSurfaceView=null;21privateSurfaceHoldermSurfaceHolder

5、=null22privateButtoncleanButton=null;23privateButtoncolorButton=null;2425privatefloatoldX=0f;26privatefloatoldY=0f;2728privatebooleancanDraw=false;29privatePaintmPaint=null;19 /用來(lái)記錄當(dāng)前是哪一種顏色3049cleanButton=(Button)this.findViewById(R.id.flushbutton);313334Override35publicvoidonCreate(BundlesavedInsta

6、nceState)3637super.onCreate(savedInstanceState);38setContentView(R.layout.main);3940mSurfaceView=(SurfaceView)this.findViewById(R.id.surfaceview);4143mPaint=newPaint();44/畫筆的顏色4546/畫筆的粗細(xì)47/按鈕監(jiān)聽(tīng)cleanButton.setOnClickListener(newView.OnClickListener()(OverridepublicvoidonClick(Viewv)(/TODOAuto-generat

7、edmethodstub/鎖定整個(gè) SurfaceViewCanvasmCanvas=mSurfaceHolder.lockCanvas();mCanvas.drawC010r(Color.BLACK);/繪制完成，提交修改mSurfaceHolder.unlockCanvasAndPost(mCanvas);/重新鎖一次mSurfaceHolder.lockCanvas(newRect(0,0,0,0);mSurfaceHolder.unlockCanvasAndPost(mCanvas););colorButton=(Button)this.findViewById(R.id.colorb

8、utton);/按鈕監(jiān)聽(tīng)colorButton.setOnClickListener(newView.OnClickListener()(OverridepublicvoidonClick(Viewv)(/TODOAuto-generatedmethodstubDialogmDialog=newAlertDialog.Builder(MyWallActivity.this).setTitle(顏色設(shè)置).setSingleChoiceItems(newString紅色,綠色,藍(lán)色,whicnewDialogInterface.OnClickListener()Overridepublicvoi

9、donClick(DialogInterfacedialog,intwhich)/TODOAuto-generatedmethodstub50515253545556575859606162636465666768697071727374757677787980hColor,81828384858688(89case0:90(91/畫筆的顏色92mPaint.setColor(Color.RED);93whichColor=0;94break;9596case1:97(98/畫筆的顏色99mPaint.setColor(Color.GREEN);100whichColor=1;101break

10、;102103case2:104(105/畫筆的顏色106mPaint.setColor(Color.BLUE);107whichColor=2;108break;109110111112)113.setPositiveButton(確定，newDialogInterface.OnClickListener()114(115116Override117publicvoidonClick(DialogInterfacedialog,int118(119/TODOAuto-generatedmethodstub120dialog.dismiss();121122)123.create();87sw

11、itch(which)which)mDialog.show();)；)OverridepublicbooleanonTouchEvent(MotionEventevent)/獲取 x 坐標(biāo)floatx=event.getX();/獲取 y 坐標(biāo)(不知道為什么要減去一個(gè)偏移值才對(duì)得準(zhǔn)屏幕)floaty=event.getY()-50;/第一次進(jìn)來(lái)先不管 if(canDraw)/獲取觸屏事件switch(event.getAction()/如果是拖動(dòng)事件caseMotionEvent.ACTION_MOVE:/鎖定整個(gè) SurfaceViewCanvasmCanvas=mSurfaceHolder

12、.lockCanvas();mCanvas.drawLine(x,y,oldX,oldY,mPaint);mSurfaceHolder.unlockCanvasAndPost(mCanvas);/重新鎖一次mSurfaceHolder.lockCanvas(newRect(0,0,0,0);mSurfaceHolder.unlockCanvasAndPost(mCanvas);break;/保存目前的 x 坐標(biāo)值124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162oldX=x;163/保存目前的