Parcelable和Parcel

Parcelable   传递对象时候用

Android序列化对象主要有两种方法，实现Serializable接口、或者实现Parcelable接口。实现Serializable接口是JavaSE本身就支持的，而Parcelable是Android特有的功能，效率比实现Serializable接口高，而且还可以用在进程间通信(IPC)中

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。

 

Intent中的运用如下：

bundle.putParcelable("key", passObject);

ParcelableObject passObject = this.getIntent()
				.getParcelableExtra("key");


 
简单实例

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

public class FilmInfo implements Parcelable {

private String filmName;
private String director;
private String starring;
private String produce;
private String summary;
private String actionTime;
private String imgUrl;

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

@SuppressWarnings("unchecked")
public FilmInfo createFromParcel(Parcel source) {
FilmInfo filmInfo = new FilmInfo();
filmInfo.filmName = source.readString();
filmInfo.director = source.readString();
filmInfo.starring = source.readString();
filmInfo.produce = source.readString();
filmInfo.summary = source.readString();
filmInfo.actionTime = source.readString();
filmInfo.imgUrl = source.readString();
return filmInfo;
}

public FilmInfo[] newArray(int size) {
return new FilmInfo[size];
}

};

@Override
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
// 按顺序写 否则数据错位
dest.writeString(filmName);
dest.writeString(director);
dest.writeString(starring);
dest.writeString(produce);
dest.writeString(summary);
dest.writeString(actionTime);
dest.writeString(imgUrl);
}

public String getDirector() {
return director;
}

public void setDirector(String director) {
this.director = director;
}

public String getStarring() {
return starring;
}

public void setStarring(String starring) {
this.starring = starring;
}

public String getSummary() {
return summary;
}

public void setSummary(String summary) {
this.summary = summary;
}

public String getImgUrl() {
return imgUrl;
}

public void setImgUrl(String imgUrl) {
this.imgUrl = imgUrl;
}

public String getFilmName() {
return filmName;
}

public void setFilmName(String filmName) {
this.filmName = filmName;
}

public String getProduce() {
return produce;
}

public void setProduce(String produce) {
this.produce = produce;
}

public String getActionTime() {
return actionTime;
}

public void setActionTime(String actionTime) {
this.actionTime = actionTime;
}

}