Android Fragment间对象传递

时间:2023-03-09 01:12:53
Android Fragment间对象传递

  由于Activity相对较为笨重,因而在日常的开发中很多时候会用到Fragment。然而Activity之间是通过Intent进行数据的传递,那Fragment是通过什么来进行传递的呢?Fragment之间又是通过什么方式来进行对象的传递呢?

  Android控件之间传递(Activity和Activity间传递对象、Fragment和Fragment间传递对象)对象有两种实现方式。一种是实现Java提供的Serializable接口,另一种是实现android提供的Parcelable接口。两者之间各有优势;实现Serializable接口的话最简单,直接添加接口的实现即可,但是效率较低;实现Parcelable的话效率较高,但需要自己实现Parcelable的方法。下面看下两种方法的具体实现:

  原有Article类

package com.example.news.andoridnewsapp;

public class Article {
private String title;
private String linkmd5;
private String link;
private String desc; public String getLinkmd5() {
return linkmd5;
} public void setLinkmd5(String linkmd5) {
this.linkmd5 = linkmd5;
} public String getLink() {
return link;
} public void setLink(String link) {
this.link = link;
} public String getDesc() {
return desc;
} public void setDesc(String desc) {
this.desc = desc;
} public String getTitle() { return title;
} public void setTitle(String title) {
this.title = title;
}
}

  一、实现Serializable,只要在public class Article后面添加接口的实现(implements Serializable)即可

package com.example.news.andoridnewsapp;

public class Article implements Serializable {
private String title;
private String linkmd5;
private String link;
private String desc; public String getLinkmd5() {
return linkmd5;
} public void setLinkmd5(String linkmd5) {
this.linkmd5 = linkmd5;
} public String getLink() {
return link;
} public void setLink(String link) {
this.link = link;
} public String getDesc() {
return desc;
} public void setDesc(String desc) {
this.desc = desc;
} public String getTitle() { return title;
} public void setTitle(String title) {
this.title = title;
}
}

  Fragment1进行参数传递

ArticleConententFragment fragment = new ArticleConententFragment();
Bundle args = new Bundle();
args.putSerializable(ARG_ARTICLE, article); fragment.setArguments(args);

  Fragment2进行参数的接收

(Article) getArguments().getSerializable(ARG_ARTICLE);

  二、实现Parcelable,如果通过Parcelable的方式进行实现的话,需要实现Parcelable接口的方法describeContents(此方法一般不用修改)、writeToParcel(主要是此方法)和创建一个Creator属性。

package com.example.news.andoridnewsapp;

import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable; //public class Article implements Serializable {
public class Article implements Parcelable {
private String title;
private String linkmd5;
private String link;
private String desc; public String getLinkmd5() {
return linkmd5;
} public void setLinkmd5(String linkmd5) {
this.linkmd5 = linkmd5;
} public String getLink() {
return link;
} public void setLink(String link) {
this.link = link;
} public String getDesc() {
return desc;
} public void setDesc(String desc) {
this.desc = desc;
} public String getTitle() { return title;
} public void setTitle(String title) {
this.title = title;
} @Override
public String toString() {
return this.title;
} @Override
public int describeContents() {
return 0;
} @Override
public void writeToParcel(Parcel dest, int flags) {
Bundle bundle = new Bundle();
bundle.putString("title", getTitle());
bundle.putString("desc", getDesc());
bundle.putString("link", getLink());
bundle.putString("linkmd5", getLinkmd5());
dest.writeBundle(bundle);
} public static final Creator<Article> CREATOR = new Creator<Article>() {
@Override
public Article createFromParcel(Parcel source) {
Bundle bundle = source.readBundle();
Article article = new Article();
article.setTitle(bundle.getString("title"));
article.setDesc(bundle.getString("desc"));
article.setLink(bundle.getString("link"));
article.setLinkmd5(bundle.getString("linkmd5"));
return article;
} @Override
public Article[] newArray(int size) {
return new Article[size];
}
};
}

  Fragment1进行参数传递

ArticleConententFragment fragment = new ArticleConententFragment();
Bundle args = new Bundle();
//args.putSerializable(ARG_ARTICLE, article);
args.putParcelable(ARG_ARTICLE, article); fragment.setArguments(args);

  Fragment2进行参数接收

//            mArticle = (Article) getArguments().getSerializable(ARG_ARTICLE);
mArticle = (Article) getArguments().getParcelable(ARG_ARTICLE);

  这样便可方便地实现对象参数的传递。其实传递的是一个Bundle对象,如果实现的是Serializable接口,则通过Bundle的putSerializable和getSerializable进行设置和获取;如果实现的是Parceable接口,则通过putParceable和getParceable进行设置和获取。