intent传对象

intent还有一个很好用的地方，就是传输对象，但要注意的是这里的传输只是将对象复制了一份通过intent进行传递，并不能达到实时更新的效果，也就是这个对象等偏重于“读”。intent对这个对象有着严格的要求----Parcel。

android提供了一种新的类型：Parcel。本类被用作封装数据的容器，封装后的数据可以通过Intent或IPC传递。 除了基本类型以

外，只有实现了Parcelable接口的类才能被放入Parcel中。

 

Parcelable实现要点：需要实现三个东西

1）writeToParcel 方法。该方法将类的数据写入外部提供的Parcel中.声明如下：

writeToParcel (Parcel dest, int flags) 具体参数含义见javadoc

2）describeContents方法。没搞懂有什么用，反正直接返回0也可以

3）静态的Parcelable.Creator接口，本接口有两个方法：

createFromParcel(Parcel in) 实现从in中创建出类的实例的功能

newArray(int size) 创建一个类型为T，长度为size的数组，仅一句话（return new T[size])即可。估计本方法是供外部类反序列化本类数组使用。

 

 package com.yingjie.jzlfapp.model.local;

 import android.os.Parcel;
 import android.os.Parcelable;

 /**
  * 类名称: Dede_MemberAnswer 功能描述：回答的视图 作者： chrizz00 创建日期： 2014-1-23 下午2:04:50
  */
 public class PersonCenterAnswer implements Parcelable {

     private Integer tid;
     // 回答问题类型
     private String tidname;

     // 回答者id
     private Integer replierid;
     // 回答者
     private String replier;

     //问题的id
     private Integer questionid;
     //问题
     private String title;

     //提问者的id
     private Integer askerid;
     //提问者
     private String asker;

     //提问的时间
     private long asktime;
     //回答的时间
     private long answertime;
     //解决的时间
     private long solvetime;

     // 被采纳的回答的id
     private Integer bestanswer;

     //回答的id
     private Integer answerid;
     //回答的内容
     private String content;

     public PersonCenterAnswer() {

     }

     public PersonCenterAnswer(Integer tid, String tidname, Integer replierid,
             String replier, Integer questionid, String title, Integer askerid,
             String asker, long asktime, long answertime, long solvetime,
             Integer bestanswer, Integer answerid, String content) {
         super();
         this.tid = tid;
         this.tidname = tidname;
         this.replierid = replierid;
         this.replier = replier;
         this.questionid = questionid;
         this.title = title;
         this.askerid = askerid;
         this.asker = asker;
         this.asktime = asktime;
         this.answertime = answertime;
         this.solvetime = solvetime;
         this.bestanswer = bestanswer;
         this.answerid = answerid;
         this.content = content;
     }

     public Integer getTid() {
         return tid;
     }

     public void setTid(Integer tid) {
         this.tid = tid;
     }

     public String getTidname() {
         return tidname;
     }

     public void setTidname(String tidname) {
         this.tidname = tidname;
     }

     public Integer getReplierid() {
         return replierid;
     }

     public void setReplierid(Integer replierid) {
         this.replierid = replierid;
     }

     public String getReplier() {
         return replier;
     }

     public void setReplier(String replier) {
         this.replier = replier;
     }

     public Integer getQuestionid() {
         return questionid;
     }

     public void setQuestionid(Integer questionid) {
         this.questionid = questionid;
     }

     public String getTitle() {
         return title;
     }

     public void setTitle(String title) {
         this.title = title;
     }

     public Integer getAskerid() {
         return askerid;
     }

     public void setAskerid(Integer askerid) {
         this.askerid = askerid;
     }

     public String getAsker() {
         return asker;
     }

     public void setAsker(String asker) {
         this.asker = asker;
     }

     public long getAsktime() {
         return asktime;
     }

     public void setAsktime(long asktime) {
         this.asktime = asktime;
     }

     public long getAnswertime() {
         return answertime;
     }

     public void setAnswertime(long answertime) {
         this.answertime = answertime;
     }

     public long getSolvetime() {
         return solvetime;
     }

     public void setSolvetime(long solvetime) {
         this.solvetime = solvetime;
     }

     public Integer getBestanswer() {
         return bestanswer;
     }

     public void setBestanswer(Integer bestanswer) {
         this.bestanswer = bestanswer;
     }

     public Integer getAnswerid() {
         return answerid;
     }

     public void setAnswerid(Integer answerid) {
         this.answerid = answerid;
     }

     public String getContent() {
         return content;
     }

     public void setContent(String content) {
         this.content = content;
     }

     public PersonCenterAnswer(Parcel source) {
185
186         this.tid = source.readInt();
187         this.tidname = source.readString();
188         this.replierid = source.readInt();
189         this.replier = source.readString();
190         this.questionid =source.readInt();
191         this.title = source.readString();
192         this.askerid = source.readInt();
193         this.asker = source.readString();
194         this.asktime = source.readLong();
195         this.answertime =  source.readLong();
196         this.solvetime =  source.readLong();
197         this.bestanswer = source.readInt();
198         this.answerid =source.readInt();
199         this.content = source.readString();
200     }

     @Override
     public int describeContents() {
         return 0;
     }

     @Override
209     public void writeToParcel(Parcel dest, int flags) {
210         dest.writeInt(tid);
211         dest.writeString(tidname);
212         dest.writeInt(replierid);
213         dest.writeString(replier);
214         dest.writeInt(questionid);
215         dest.writeString(title);
216         dest.writeInt(askerid);
217         dest.writeString(asker);
218         dest.writeLong(asktime);
219         dest.writeLong(answertime);
220         dest.writeLong(solvetime);
221         dest.writeInt(bestanswer);
222         dest.writeInt(answerid);
223         dest.writeString(content);
224     }

       public static final Parcelable.Creator<PersonCenterAnswer> CREATOR = new Parcelable.Creator<PersonCenterAnswer>(){

         @Override
         public PersonCenterAnswer createFromParcel(Parcel source) {

             return new PersonCenterAnswer(source);
         }

         @Override
         public PersonCenterAnswer[] newArray(int size) {

             return new PersonCenterAnswer[size];
         }

       };

     @Override
     public String toString() {
         return "PersonCenterAnswer [tid=" + tid + ", tidname=" + tidname
                 + ", replierid=" + replierid + ", replier=" + replier
                 + ", questionid=" + questionid + ", title=" + title
                 + ", askerid=" + askerid + ", asker=" + asker + ", asktime="
                 + asktime + ", answertime=" + answertime + ", solvetime="
                 + solvetime + ", bestanswer=" + bestanswer + ", answerid="
                 + answerid + ", content=" + content + "]";
     }

 }

writeToParcel (Parcel dest, int flags) 和PersonCenterAnswer(Parcel source)方法体里面的write和read的顺序要一一对应，不能出错！！切记！！

传输的时候直接intent.putExtra("answers", answerss);    (answers=PersonCenterAnswer)

在接收端直接  PersonCenterAnswer person =（PersonCenterAnswer） getIntent().getParcelableExtra("answers");

再次注意：这个person只是一个复制品，并不是传输前的那个对象。

如果需要同步，可以考虑将这个对象回传回去，在替换成先前的那个对象，试过可行，稍麻烦。