fix: 修复了声明周期问题，以及销毁之后再次使用，由于 delegate property 会被再次初始化，出现的异常 (#31)

hi-dhl · Apr 27, 2022 · fa65b08 · fa65b08
1 parent e0a2488
commit fa65b08
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Showing 3 changed files with 32 additions and 12 deletions.
diff --git a/app/build.gradle b/app/build.gradle
@@ -47,7 +47,7 @@ dependencies {
     ext.material = "1.2.1"
     ext.appcompat = "1.2.0"
     ext.ktx = "1.3.2"
-    ext.remote = true
+    ext.remote = false
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
     implementation "androidx.core:core-ktx:${ktx}"

diff --git a/binding/src/main/java/com/hi/dhl/binding/base/FragmentDelegate.kt b/binding/src/main/java/com/hi/dhl/binding/base/FragmentDelegate.kt
@@ -1,9 +1,9 @@
 package com.hi.dhl.binding.base
 
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentManager
 import androidx.viewbinding.ViewBinding
 import com.hi.dhl.binding.observerWhenCreated
-import com.hi.dhl.binding.observerWhenDestroyed
 import kotlin.properties.ReadOnlyProperty
 
 /**
@@ -21,18 +21,21 @@ abstract class FragmentDelegate<T : ViewBinding>(
 
     init {
 
-        /**
-         * 感谢 architecture-components-samples 提供的思路
-         *
-         * 最原始的处理的方案 监听 Fragment 的生命周期，会存在 Fragment 和 Fragment 中的 View 生命周期不一致问题
-         * 详情查看 [issue][https://github.com/hi-dhl/Binding/issues/15]
-         */
+        // 详情查看 [issue][https://github.com/hi-dhl/Binding/issues/31#issuecomment-1109729949]
         fragment.lifecycle.observerWhenCreated {
-            fragment.viewLifecycleOwnerLiveData.observe(fragment) { viewOwner ->
-                viewOwner.lifecycle.observerWhenDestroyed {
-                    destroyed()
+            val fragmentManager = fragment.requireFragmentManager()
+            fragmentManager.registerFragmentLifecycleCallbacks(object :
+                FragmentManager.FragmentLifecycleCallbacks() {
+                override fun onFragmentViewDestroyed(fm: FragmentManager, f: Fragment) {
+                    super.onFragmentViewDestroyed(fm, f)
+                    // 检查 fragment 的目的，为了防止类似于加载多个 Fragment 场景销毁的时候，出现不必要的异常
+                    if (f == fragment) {
+                        destroyed()
+                        fragmentManager.unregisterFragmentLifecycleCallbacks(this)
+                    }
+
                 }
-            }
+            }, false)
         }
 
     }

diff --git a/binding/src/main/java/com/hi/dhl/binding/viewbind/FragmentViewBinding.kt b/binding/src/main/java/com/hi/dhl/binding/viewbind/FragmentViewBinding.kt
@@ -1,10 +1,12 @@
 package com.hi.dhl.binding.viewbind
 
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.Lifecycle
 import androidx.viewbinding.ViewBinding
 import com.hi.dhl.binding.base.FragmentDelegate
 import com.hi.dhl.binding.bindMethod
 import com.hi.dhl.binding.inflateMethod
+import java.lang.Exception
 import kotlin.reflect.KProperty
 
 /**
@@ -28,6 +30,21 @@ class FragmentViewBinding<T : ViewBinding>(
 
         } ?: let {
 
+            try {
+                /**
+                 * 检查目的，是为了防止在 onCreateView() or after onDestroyView() 使用 binding。
+                 * 另外在销毁之后，如果再次使用，由于 delegate property 会被再次初始化
+                 *
+                 * 捕获这个异常的原因，是为了兼容之前的版本，防止因为升级，造成崩溃，如果不正确使用，将会输出一些日志作为警告
+                 */
+                check(thisRef.viewLifecycleOwner.lifecycle.currentState.isAtLeast(Lifecycle.State.INITIALIZED)) {
+                    "cannot use binding in before onCreateView() or after onDestroyView() from 1.1.3. about [issue](https://github.com/hi-dhl/Binding/issues/31#issuecomment-1109733307)"
+                }
+            } catch (e: Exception) {
+                e.printStackTrace()
+            }
+
+
             val bind: T
             if (thisRef.view == null) {
                 // 这里为了兼容在 navigation 中使用 Fragment