android 浅复制和深复制-clone篇

有关java中的 浅复制和深复制

，这里不详细讨论。相关知识请参考以下帖子：

浅复制和深复制http://blog.csdn.net/yang_hui1986527/article/details/7029777
浅析Java中的深拷贝与浅拷贝http://blog.csdn.net/yang_hui1986527/article/details/7012428

android中的 浅复制和深复制，具体可能于java中的有一点不同。下面，我们来探讨下在这个问题。

主要思路：

1、创建TextBox，然后根据TextBox复制出一个对象TextBox2（点击屏幕，进行复制）；

2、改变TextBox2的位置，方便观察比较差异。

3、改变TextBox2内部文本的位置。如果是浅复制，那么TextBox2内部文本改变位置的同时，TextBox内部文本的位置会随着改变。否则，如果是深度复制，TextBox内部文本的位置不会改变。

效果如下：

注：请注意文本“test”在文本框内的位置。

浅复制：

                                      

深复制：

                                           

源程序：

(点击下载：http://download.csdn.net/detail/yang_hui1986527/3874905)

CloneActivity.java

package com.clone;import android.app.Activity;import android.os.Bundle;public class CloneActivity extends Activity {    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        //setContentView(R.layout.main);        CloneView mCloneView = new CloneView(this);        setContentView(mCloneView);    }}

CloneView.java

package com.clone;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.PointF;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;public class CloneView extends View {private Document mDocument = null;public Paint mPaint= null;public TextBox mTextBox = null;public TextBox mTextBox2 = null;public CloneView(Context context) {super(context);mDocument = new Document();mPaint = new Paint();initData();}public CloneView(Context context, AttributeSet attrs) {super(context, attrs);mDocument = new Document();mPaint = new Paint();initData();}public CloneView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);mDocument = new Document();}public void initData(){PointF textpos = new PointF(30,30);String text = new String("test");mTextBox = new TextBox(50, 50, 100, 100, textpos, text);mDocument.add(mTextBox);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);canvas.drawColor(Color.WHITE);mDocument.draw(canvas, mPaint);}@Overridepublic boolean onTouchEvent(MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:{try {mTextBox2 = (TextBox)mTextBox.clone();mTextBox2.moveBound();mTextBox2.changeData();} catch (CloneNotSupportedException e) {e.printStackTrace();}if(mTextBox2 != null)mDocument.add(mTextBox2);}invalidate();break;case MotionEvent.ACTION_MOVE:break;case MotionEvent.ACTION_UP:break;default:break;}return super.onTouchEvent(event);}}

Document.java

package com.clone;import java.util.Vector;import android.graphics.Canvas;import android.graphics.Paint;public class Document {private Vector<Object> objs = null;public Document() {objs = new Vector<Object>();}public void add(Object obj){objs.add(obj);}void draw(Canvas canvas, Paint paint) {canvas.save();for (int i = 0; i < objs.size(); i++) {Object obj = objs.get(i);obj.draw(canvas, paint);}canvas.restore();}}

Object.java

package com.clone;import android.graphics.Canvas;import android.graphics.Paint;public abstract class Object implements Cloneable{protected float posx = 0;protected float posy =0;protected float width = 0;protected float height = 0;public Object() {posx = 0;posy =0;width = 0;height = 0;}public Object(float posx,float posy,float width,float height){this.posx = posx;this.posy = posy;this.width = width;this.height = height;}public void moveBound() {this.posx += 100;this.posy += 100;}abstract  void draw(Canvas canvas,Paint paint);abstract  void changeData();    public Object clone() throws CloneNotSupportedException {          return (Object) super.clone();      }  }

TextBox.java

package com.clone;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Paint.Style;import android.graphics.PointF;public class TextBox extends Object implements Cloneable{private PointF mtextpos = null;private String mtextString = null;public TextBox() {posx = 0;posy =0;width = 0;height = 0;mtextpos = new PointF();mtextString = new String();}public TextBox(float posx, float posy, float width, float height,PointF textpos,String text) {this.posx = posx;this.posy = posy;this.width = width;this.height = height;mtextpos = new PointF(textpos.x,textpos.y);mtextString = new String(text);}@Overridevoid draw(Canvas canvas, Paint paint) {canvas.save();paint.setColor(Color.BLUE);paint.setStyle(Style.STROKE);canvas.drawRect(posx, posy, posx+width, posy+height, paint);canvas.translate(posx, posy);paint.setColor(Color.BLACK);paint.setTextSize(20);canvas.drawText(mtextString, mtextpos.x, mtextpos.y, paint);canvas.restore();}//////浅克隆//    public TextBox clone() throws CloneNotSupportedException {  //        return (TextBox) super.clone();  //    }      //深克隆    public TextBox clone() throws CloneNotSupportedException {          TextBox o =  (TextBox) super.clone();                   //对于string，int等基本类型，用上面一句就可以        //对于复杂类型，例如PointF等还需要手动实现拷贝        if(mtextpos != null)        o.mtextpos = new PointF(mtextpos.x,mtextpos.y);                return o;    }@Overridevoid changeData() {        if(mtextpos != null)        mtextpos.offset(20, 50);} }