Merge pull request #5 from iamsee/master

修复从视频详情页跳转到主页面重复添加fragment的问题，及由此导致的fragment不断累加重叠问题

Author: git-xuhao

app/src/main/java/com/hazz/kotlinmvp/ui/activity/MainActivity.kt

@@ -84,23 +84,73 @@ class MainActivity : BaseActivity() {
     private fun switchFragment(position: Int) {
         val transaction = supportFragmentManager.beginTransaction()
         hideFragments(transaction)
+//        showToast(supportFragmentManager.fragments.size.toString())
+        /*重复进入退出视频详情页会导致fragment不断增加*/
+//        when (position) {
+//            0 //首页
+//            -> if (mHomeFragment == null) {
+//
+//                mHomeFragment = HomeFragment.getInstance(mTitles[position])
+//                transaction.add(R.id.fl_container, mHomeFragment, "home")
+//            } else {
+//                transaction.show(mHomeFragment)
+//            }
+//            1 //发现
+//            -> if (mDiscoveryFragment == null) {
+//                mDiscoveryFragment = DiscoveryFragment.getInstance(mTitles[position])
+//                transaction.add(R.id.fl_container, mDiscoveryFragment, "discovery")
+//            } else {
+//                transaction.show(mDiscoveryFragment)
+//            }
+//            2 //热门
+//            -> if ( mHotFragment == null) {
+//                mHotFragment = HotFragment.getInstance(mTitles[position])
+//                transaction.add(R.id.fl_container, mHotFragment, "hot")
+//            }
+//            else {
+//                transaction.show(mHotFragment)
+//            }
+//
+//            3 //我的
+//            -> if (mMineFragment == null) {
+//                mMineFragment = MineFragment.getInstance(mTitles[position])
+//                transaction.add(R.id.fl_container, mMineFragment, "mine")
+//            } else {
+//                transaction.show(mMineFragment)
+//            }
+//            else -> {
+//
+//            }
+//        }
         when (position) {
             0 //首页
             -> if (mHomeFragment == null) {
+                var cacheMHomeFragment = supportFragmentManager.findFragmentByTag("home")
+                if(cacheMHomeFragment != null){
+                    transaction.remove(cacheMHomeFragment)
+                }
                 mHomeFragment = HomeFragment.getInstance(mTitles[position])
                 transaction.add(R.id.fl_container, mHomeFragment, "home")
             } else {
                 transaction.show(mHomeFragment)
             }
             1 //发现
             -> if (mDiscoveryFragment == null) {
+                var cacheMDiscoveryFragment = supportFragmentManager.findFragmentByTag("discovery")
+                if(cacheMDiscoveryFragment != null){
+                    transaction.remove(cacheMDiscoveryFragment)
+                }
                 mDiscoveryFragment = DiscoveryFragment.getInstance(mTitles[position])
                 transaction.add(R.id.fl_container, mDiscoveryFragment, "discovery")
             } else {
                 transaction.show(mDiscoveryFragment)
             }
             2 //热门
             -> if ( mHotFragment == null) {
+                var cacheMHotFragment = supportFragmentManager.findFragmentByTag("hot")
+                if(cacheMHotFragment != null){
+                    transaction.remove(cacheMHotFragment)
+                }
                 mHotFragment = HotFragment.getInstance(mTitles[position])
                 transaction.add(R.id.fl_container, mHotFragment, "hot")
             }
@@ -110,6 +160,10 @@ class MainActivity : BaseActivity() {
 
             3 //我的
             -> if (mMineFragment == null) {
+                var cacheMMineFragment = supportFragmentManager.findFragmentByTag("mine")
+                if(cacheMMineFragment != null){
+                    transaction.remove(cacheMMineFragment)
+                }
                 mMineFragment = MineFragment.getInstance(mTitles[position])
                 transaction.add(R.id.fl_container, mMineFragment, "mine")
             } else {
@@ -130,29 +184,54 @@ class MainActivity : BaseActivity() {
      * @param transaction transaction
      */
     private fun hideFragments(transaction: FragmentTransaction) {
-        if (null != mHomeFragment) {
-            transaction.hide(mHomeFragment)
+        /*mHomeFragment 丢失问题应该用全局查找替代*/
+//        if (null != mHomeFragment) {
+//            transaction.hide(mHomeFragment)
+//        }
+//        if (null != mDiscoveryFragment) {
+//            transaction.hide(mDiscoveryFragment)
+//        }
+//        if (null != mHotFragment) {
+//            transaction.hide(mHotFragment)
+//        }
+//        if (null != mMineFragment) {
+//            transaction.hide(mMineFragment)
+//        }
+        var cacheMHomeFragment = supportFragmentManager.findFragmentByTag("home")
+
+        var cacheMDiscoveryFragment = supportFragmentManager.findFragmentByTag("discovery")
+        var cacheMMineFragment = supportFragmentManager.findFragmentByTag("hot")
+        var cacheMHotFragment = supportFragmentManager.findFragmentByTag("mine")
+        if (null != cacheMHomeFragment) {
+            transaction.hide(cacheMHomeFragment)
         }
-        if (null != mDiscoveryFragment) {
-            transaction.hide(mDiscoveryFragment)
+        if (null != cacheMDiscoveryFragment) {
+            transaction.hide(cacheMDiscoveryFragment)
         }
-        if (null != mHotFragment) {
-            transaction.hide(mHotFragment)
+        if (null != cacheMMineFragment) {
+            transaction.hide(cacheMMineFragment)
         }
-        if (null != mMineFragment) {
-            transaction.hide(mMineFragment)
+        if (null != cacheMHotFragment) {
+            transaction.hide(cacheMHotFragment)
         }
 
+
     }
 
 
     override fun onSaveInstanceState(outState: Bundle) {
+//        showToast("onSaveInstanceState->"+mIndex)
         super.onSaveInstanceState(outState)
         //记录fragment的位置,防止崩溃 activity被系统回收时，fragment错乱
         if (tab_layout != null) {
             outState.putInt("currTabIndex", mIndex)
         }
     }
+    override fun onRestoreInstanceState(savedInstanceState: Bundle?) {
+//        showToast("onRestoreInstanceState->"+mIndex)
+//        switchFragment(savedInstanceState!!.getInt( mIndex.toString() ));
+//        super.onRestoreInstanceState(savedInstanceState)
+    }
 
     override fun initView() {