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。