FragmentHelper-白红宇

FragmentHelper

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发布时间：2019-06-18

本文共 6085 字，大约阅读时间需要 20 分钟。

1 package com.icitymobile.anda.util;  2   3 import java.lang.ref.SoftReference;  4 import java.util.ArrayList;  5 import java.util.HashMap;  6 import java.util.Iterator;  7 import java.util.Map;  8 import java.util.Map.Entry;  9  10 import android.content.Context; 11 import android.content.Intent; 12 import android.os.Bundle; 13 import android.support.v4.app.Fragment; 14 import android.support.v4.app.FragmentManager; 15 import android.support.v4.app.FragmentTransaction; 16  17 import com.hualong.framework.log.Logger; 18  19 /** 20  * Fragment帮助类 21  */ 22 public class FragmentHelper { 23  24     public static final String TAG = "FragmentHelper"; 25  26     private static final String STATE_IDS = "fragment_ids"; 27     private static final String STATE_CURRENT_FRAGMENT_ID = "current_fragment_id"; 28     private static final String STATE_LAST_FRAGMENT = "last_fragment"; 29  30     private Context mContext; 31     private FragmentManager mManager; 32     private int mContainerId; 33  34     private Map
     
      > mFragments = new HashMap
      
       >(); 35     private String mCurrentFragmentId = null; 36     private Fragment mLastFragment; 37  38     public FragmentHelper(Context context, FragmentManager manager, int containerId) { 39         mContext = context; 40         mManager = manager; 41         mContainerId = containerId; 42     } 43  44     public Fragment getFragment(String fragmentId) { 45         Fragment fragment = null; 46         SoftReference
       
         reference = mFragments.get(fragmentId); 47         if (reference != null) { 48             fragment = reference.get(); 49         } 50         return fragment; 51     } 52  53     public String getCurrentFragmentId() { 54         return mCurrentFragmentId; 55     } 56  57     public Fragment getCurrentFragment() { 58         return getFragment(getCurrentFragmentId()); 59     } 60  61     public void switchFragment(String id, Intent intent) { 62         switchFragment(id, intent, -1); 63     } 64  65     public void switchFragment(String id, Intent intent, int transition) { 66         if (intent == null) { 67             return; 68         } 69         Fragment newFragment = getFragment(id); 70         if (mLastFragment == null || mLastFragment != newFragment) { 71             FragmentTransaction ft = mManager.beginTransaction(); 72             if (mLastFragment != null) { 73                 ft.hide(mLastFragment); 74             } 75             if (newFragment == null) { 76                 Logger.i(TAG, TAG + ": Instantiate a new fragment " + id); 77                 String fname = intent.getComponent().getClassName(); 78                 Bundle args = intent.getExtras(); 79                 newFragment = Fragment.instantiate(mContext, fname); 80                 if (args != null) { 81                     newFragment.setArguments(args); 82                 } 83                 mFragments.put(id, new SoftReference
        
         (newFragment)); 84                 ft.add(mContainerId, newFragment, id); 85             } else { 86                 Logger.i(TAG, TAG + ": Load an old fragment " + id); 87                 ft.show(newFragment); 88             } 89             if (transition != -1) { 90                 ft.setTransition(transition); 91             } 92             mLastFragment = newFragment; 93             mCurrentFragmentId = id; 94             ft.commit(); 95 //            mManager.executePendingTransactions(); 96         } 97     } 98  99     /**100      * 在Bundle中保存状态101      *102      * @param bundle103      */104     public void saveInBundle(Bundle bundle) {105         if (bundle == null) {106             return;107         }108         Logger.i(TAG, TAG + ": saving in bundle");109         ArrayList
         
           idList = new ArrayList
          
           (mFragments.keySet());110 bundle.putStringArrayList(STATE_IDS, idList);111 112 Iterator
           
            
             >> iter = mFragments.entrySet().iterator();113 Entry
             
              > entry;114 SoftReference
              
                reference;115 Fragment fragment;116 while (iter.hasNext()) {117 entry = iter.next();118 reference = entry.getValue();119 if (reference != null) {120 fragment = reference.get();121 if (fragment != null) {122 mManager.putFragment(bundle, entry.getKey(), fragment);123 }124 }125 }126 127 if (mCurrentFragmentId != null) {128 bundle.putString(STATE_CURRENT_FRAGMENT_ID, mCurrentFragmentId);129 }130 131 if (mLastFragment != null) {132 mManager.putFragment(bundle, STATE_LAST_FRAGMENT, mLastFragment);133 }134 }135 136 /**137 * 在Bundle中保存状态，只保存当前的fragment138 *139 * @param bundle140 */141 public void saveStateSimple(Bundle bundle) {142 if (bundle == null) {143 return;144 }145 Logger.i(TAG, TAG + ": saving in bundle simple");146 147 if (mCurrentFragmentId != null) {148 bundle.putString(STATE_CURRENT_FRAGMENT_ID, mCurrentFragmentId);149 150 ArrayList
               
                 idList = new ArrayList
                
                 (1);151 idList.add(mCurrentFragmentId);152 bundle.putStringArrayList(STATE_IDS, idList);153 154 Fragment currentFragment = getCurrentFragment();155 if (currentFragment != null) {156 mManager.putFragment(bundle, mCurrentFragmentId, currentFragment);157 }158 }159 160 if (mLastFragment != null) {161 mManager.putFragment(bundle, STATE_LAST_FRAGMENT, mLastFragment);162 }163 }164 165 /**166 * 从Bundle中恢复状态167 *168 * @param bundle169 */170 public void restoreFromBundle(Bundle bundle) {171 if (bundle == null) {172 return;173 }174 Logger.i(TAG, TAG + ": restoring from bundle");175 ArrayList
                 
                   idList = bundle.getStringArrayList(STATE_IDS);176 if (idList != null) {177 Fragment fragment;178 for (String id : idList) {179 fragment = mManager.getFragment(bundle, id);180 if (fragment != null) {181 mFragments.put(id, new SoftReference
                  
                   (fragment));182 }183 }184 }185 186 String currentId = bundle.getString(STATE_CURRENT_FRAGMENT_ID);187 if (currentId != null) {188 mCurrentFragmentId = currentId;189 }190 191 Fragment lastFragment = mManager.getFragment(bundle, STATE_LAST_FRAGMENT);192 if (lastFragment != null) {193 mLastFragment = lastFragment;194 }195 }196 }