android涂鸦版手写版代码

1、一、概述这次要做一个简单的涂鸦板应用，以前在Qt上实现过，突然想到要把它在Android上实现，呵呵，既简单又有趣。二、实现新建工程MyWall,修改/res/layout/main.xml文件，在里面添加一个SurfaceView和两个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开发实例篇（1）简易涂鸦板232431323940复制代码接着，修改MyWallActivity.java文件，最主要是覆写了onTouchEvent()函数，在这个函数里过滤出触屏拖动事件，然后获取其相应的坐标和画线，关于SurfaceView的用法在基础篇里有讲到。完整的内容如下：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 /用来记录当前是哪一种颜色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/画笔的颜色4546/画笔的粗细47/按钮监听cleanButton.setOnClickListener(newView.OnClickListener()(OverridepublicvoidonClick(Viewv)(/TODOAuto-generat

7、edmethodstub/锁定整个 SurfaceViewCanvasmCanvas=mSurfaceHolder.lockCanvas();mCanvas.drawC010r(Color.BLACK);/绘制完成，提交修改mSurfaceHolder.unlockCanvasAndPost(mCanvas);/重新锁一次mSurfaceHolder.lockCanvas(newRect(0,0,0,0);mSurfaceHolder.unlockCanvasAndPost(mCanvas););colorButton=(Button)this.findViewById(R.id.colorb

8、utton);/按钮监听colorButton.setOnClickListener(newView.OnClickListener()(OverridepublicvoidonClick(Viewv)(/TODOAuto-generatedmethodstubDialogmDialog=newAlertDialog.Builder(MyWallActivity.this).setTitle(颜色设置).setSingleChoiceItems(newString红色,绿色,蓝色,whicnewDialogInterface.OnClickListener()Overridepublicvoi

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

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

11、itch(which)which)mDialog.show();)；)OverridepublicbooleanonTouchEvent(MotionEventevent)/获取 x 坐标floatx=event.getX();/获取 y 坐标(不知道为什么要减去一个偏移值才对得准屏幕)floaty=event.getY()-50;/第一次进来先不管 if(canDraw)/获取触屏事件switch(event.getAction()/如果是拖动事件caseMotionEvent.ACTION_MOVE:/锁定整个 SurfaceViewCanvasmCanvas=mSurfaceHolder

12、.lockCanvas();mCanvas.drawLine(x,y,oldX,oldY,mPaint);mSurfaceHolder.unlockCanvasAndPost(mCanvas);/重新锁一次mSurfaceHolder.lockCanvas(newRect(0,0,0,0);mSurfaceHolder.unlockCanvasAndPost(mCanvas);break;/保存目前的 x 坐标值124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162oldX=x;163/保存目前的