Android:Activity+Fragment及它们之间的数据交换（一）

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我是靠谱客的博主安详黑裤，最近开发中收集的这篇文章主要介绍Android:Activity+Fragment及它们之间的数据交换（一），觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

2014-05-18 我来说两句来源：Android:Activity+Fragment及它们之间的数据交换（一）收藏我要投稿简介：为什么要用Fragment？使用Fragment可以在一个Activity中实现不同的界面。Fragment与Fragment之间的动画切换，远比Activity与Activity之间的动画切换变化方式多。很多时候，我们通过使用一个Activity，切换多个Fragment。本次博客，主要列举一下Fragment与它的Activity之间进行数据交换的方式。

1.Fragment中通过getActivity()然后进行强制转化，调用Activity中的公有方法((XXXXActivity)getActivity()).fun();2.Activity在切换Fragment的时候，通过setArguments向Fragment传递参数，Fragment通过getArguments();获得从activity中传递过来的值3.Activity实现一个接口，Fragment在onAttach方法中，将该Activity转化为该接口，在需要调用的时候回调。注意：本Demo是通过FragmentManager来管理Fragment的，通过FragmentManager管理，我们创建Fragment和销毁Fragment的时候，可以通过栈的方式：a.FragmentTransaction的add方法，添加一个Fragmentb.FragmentTransaction的popBackStack()弹出该Fragment演示实例：fragment1.xml?1234 MyFragment1.java?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051/* * $filename: MyFragment.java,v $ * $Date: 2014-5-16 $ * Copyright (C) ZhengHaibo, Inc. All rights reserved. * This software is Made by Zhenghaibo. */package com.example.testfragment; import android.app.Activity;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.Button; /* *@author: ZhengHaibo *web: http://blog.csdn.net/nuptboyzhb *mail: zhb931706659@126.com *2014-5-16 Nanjing,njupt,China */public class MyFragment1 extends Fragment { FragmentCallBack fragmentCallBack = null; Button btn; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment1, container, false); btn = (Button)rootView.findViewById(R.id.btn); btn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub fragmentCallBack.callbackFun1(null); } }); return rootView; } @Override public void onAttach(Activity activity) { // TODO Auto-generated method stub super.onAttach(activity); fragmentCallBack = (MainActivity)activity; }}fragment2.xml?123456 MyFragment2.java?12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364/* * $filename: MyFragment.java,v $ * $Date: 2014-5-16 $ * Copyright (C) ZhengHaibo, Inc. All rights reserved. * This software is Made by Zhenghaibo. */package com.example.testfragment; import android.app.Activity;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.Button;import android.widget.Toast; /* *@author: ZhengHaibo *web: http://blog.csdn.net/nuptboyzhb *mail: zhb931706659@126.com *2014-5-16 Nanjing,njupt,China */public class MyFragment2 extends Fragment { FragmentCallBack fragmentCallBack = null; Button btn1; Button btn2; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment2, container, false); Bundle data = getArguments();//获得从activity中传递过来的值 Toast.makeText(getActivity(), data.getString("TEXT"), Toast.LENGTH_SHORT).show(); btn1 = (Button)rootView.findViewById(R.id.btn1); btn1.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 直接调用Activity中的方法 ((MainActivity)getActivity()).changeButtonColor(); } }); btn2 = (Button)rootView.findViewById(R.id.btn2); btn2.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 回调的方式 fragmentCallBack.callbackFun2(null); } }); return rootView; } @Override public void onAttach(Activity activity) { // TODO Auto-generated method stub super.onAttach(activity); fragmentCallBack = (MainActivity)activity; }}回调接口：?123456789101112131415161718192021/* * $filename: FragmentCallBack.java,v $ * $Date: 2014-5-16 $ * Copyright (C) ZhengHaibo, Inc. All rights reserved. * This software is Made by Zhenghaibo. */package com.example.testfragment; import android.os.Bundle; /* *@author: ZhengHaibo *web: http://blog.csdn.net/nuptboyzhb *mail: zhb931706659@126.com *2014-5-16 Nanjing,njupt,China */public interface FragmentCallBack { public void callbackFun1(Bundle arg); public void callbackFun2(Bundle arg);}main.xml?1234 MainActivity.java?12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485package com.example.testfragment; import android.graphics.Color;import android.os.Bundle;import android.support.v4.app.Fragment;import android.support.v4.app.FragmentManager;import android.support.v4.app.FragmentTransaction;import android.support.v7.app.ActionBarActivity;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button; public class MainActivity extends ActionBarActivity implements FragmentCallBack{ private Button btn; private MyFragment1 fragment1; private MyFragment2 fragment2; private FragmentManager fragmentManager; private Fragment currentFragment; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); fragmentManager = getSupportFragmentManager(); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragmentTransaction.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out); fragment1 = new MyFragment1(); Bundle data = new Bundle(); data.putString("TEXT", "这是Activiy通过Bundle传递过来的值"); fragment1.setArguments(data);//通过Bundle向Activity中传递值 fragmentTransaction.add(R.id.rl_container,fragment1);//将fragment1设置到布局上 fragmentTransaction.addToBackStack(null); fragmentTransaction.commitAllowingStateLoss(); currentFragment = fragment1; //初始化button控件 btn = (Button)findViewById(R.id.btn); btn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if(currentFragment instanceof MyFragment1){ switchFragment(); }else{//当前是fragment2，因此，只需要将fragment2出栈即可变成fragment1 fragmentManager.popBackStack(); currentFragment = fragment1; } } }); } /** * 切换Fragment */ private void switchFragment(){ if(null == fragment2){//可以避免切换的时候重复创建 fragment2 = new MyFragment2(); } Bundle data = new Bundle(); data.putString("TEXT", "传递给fragment2"); fragment2.setArguments(data); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragmentTransaction.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out); fragmentTransaction.add(R.id.rl_container,fragment2); fragmentTransaction.addToBackStack(null); fragmentTransaction.commitAllowingStateLoss(); currentFragment = fragment2; } public void changeButtonColor(){ btn.setBackgroundColor(Color.RED); } @Override public void callbackFun1(Bundle arg) { // TODO Auto-generated method stub switchFragment();//通过回调方式切换 } @Override public void callbackFun2(Bundle arg) { // TODO Auto-generated method stub changeButtonColor();//通过回调方式调用Activity中的方法 } }初始画面切换到第二个Fragment之后，通过Fragment2回调，改变按钮背景后的截图。注意：1.直接在Fragment中通过getActivity然后强转Activity的方式调用Activity的方法，这个方式不推荐！因为这会使Fragment的适配性变差。解决方法：在使用之前，使用instanceof 判断一下Activity的类型2.FragmentTransaction通过使用setCustomAnimations方法，可以为Fragment的切换增添各种不同的动画。变化方式远比Activity与Activity之间的切换动画要多。3.多个Fragment之间，可以通过Activity复用很多代码，提高效率。4.我们还可以通过ViewPager来管理Fragment，通过Adapter添加多个Fragment，然后通过setcurrentitem进行切换。我们同样可以通过setArguments向Fragment传递数据。