优化plus

app/src/main/java/com/example/myapplication/MainActivity.kt

@@ -6,6 +6,7 @@ import android.view.View
 import android.widget.Toast
 import androidx.activity.OnBackPressedCallback
 import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.NavController
 import androidx.navigation.fragment.NavHostFragment
@@ -28,6 +29,8 @@ class MainActivity : AppCompatActivity() {
 
     private var currentTabTag = TAB_HOME
     private var pendingTabAfterLogin: String? = null
+    private var isSwitchingTab = false
+    private var pendingTabSwitchTag: String? = null
 
     private val protectedTabs = setOf(
         R.id.shop_graph,
@@ -360,32 +363,58 @@ class MainActivity : AppCompatActivity() {
 
         val fm = supportFragmentManager
         if (fm.isStateSaved) return
+        if (isSwitchingTab) {
+            pendingTabSwitchTag = targetTag
+            return
+        }
+
+        val targetHost = when (targetTag) {
+            TAB_SHOP -> shopHost
+            TAB_MINE -> mineHost
+            else -> homeHost
+        }
+        val currentHost = currentTabHost
 
         currentTabTag = targetTag
+        isSwitchingTab = true
 
-        fm.beginTransaction()
+        val transaction = fm.beginTransaction()
             .setReorderingAllowed(true)
-            .hide(homeHost)
-            .hide(shopHost)
-            .hide(mineHost)
-            .also { ft ->
-                when (targetTag) {
-                    TAB_SHOP -> ft.show(shopHost)
-                    TAB_MINE -> ft.show(mineHost)
-                    else -> ft.show(homeHost)
+
+        if (force) {
+            transaction
+                .hide(homeHost)
+                .hide(shopHost)
+                .hide(mineHost)
+                .show(targetHost)
+        } else if (currentHost != targetHost) {
+            transaction
+                .hide(currentHost)
+                .show(targetHost)
+        }
+
+        transaction
+            .setMaxLifecycle(homeHost, if (targetHost == homeHost) Lifecycle.State.RESUMED else Lifecycle.State.STARTED)
+            .setMaxLifecycle(shopHost, if (targetHost == shopHost) Lifecycle.State.RESUMED else Lifecycle.State.STARTED)
+            .setMaxLifecycle(mineHost, if (targetHost == mineHost) Lifecycle.State.RESUMED else Lifecycle.State.STARTED)
+            .setPrimaryNavigationFragment(targetHost)
+            .runOnCommit {
+                isSwitchingTab = false
+                updateBottomNavVisibility()
+
+                if (!force) {
+                    currentTabNavController.currentDestination?.id?.let { destId ->
+                        reportPageView(source = "switch_tab", destId = destId)
+                    }
+                }
+
+                val pendingTag = pendingTabSwitchTag
+                pendingTabSwitchTag = null
+                if (pendingTag != null && pendingTag != currentTabTag) {
+                    switchTab(pendingTag)
                 }
             }
             .commit()
-
-        // ✅ 关键：hide/show 切 tab 不会触发 destinationChanged，所以手动刷新
-        bottomNav.post { updateBottomNavVisibility() }
-
-        // ✅ 新增：切 tab 后补一次路由上报（不改变其它逻辑）
-        if (!force) {
-            currentTabNavController.currentDestination?.id?.let { destId ->
-                reportPageView(source = "switch_tab", destId = destId)
-            }
-        }
     }
 
     /** 打开全局页（login/recharge等） */