Android事务过大异常，不知道是什么原因引起的。

Question

我不知道是什么原因导致我的一个Fragment屏幕出现了异常。

我已经使用TooLargeTool进行调试，得到以下输出：

2-19 18:20:24.317 25554 25554 D TooLargeTool: * android:support:fragments = 23.9 KB
12-19 18:20:24.317 25554 25554 D TooLargeTool: * android:view_state = 0.1 KB
12-19 18:20:24.317 25554 25554 D TooLargeTool: * android-support-nav:fragment:defaultHost = 0.1 KB
12-19 18:20:28.735 25554 25554 D TooLargeTool: MainActivity.onSaveInstanceState wrote: Bundle@264718100 contains 3 keys and measures 2,554.3 KB when serialized as a Parcel
12-19 18:20:28.735 25554 25554 D TooLargeTool: * android:fragments = 0.4 KB
12-19 18:20:28.735 25554 25554 D TooLargeTool: * android:viewHierarchyState = 4.0 KB
12-19 18:20:28.735 25554 25554 D TooLargeTool: * android:support:fragments = 2,549.9 KB
12-19 18:20:28.736 25554 25554 D TooLargeTool: BillingFragment.onSaveInstanceState wrote: Bundle@217680829 contains 0 keys and measures 0.0 KB when serialized as a Parcel
12-19 18:20:28.759 25554 25554 D TooLargeTool: NavHostFragment.onSaveInstanceState wrote: Bundle@148914 contains 4 keys and measures 25.1 KB when serialized as a Parcel
12-19 18:20:28.759 25554 25554 D TooLargeTool: * android-support-nav:fragment:navControllerState = 0.9 KB
12-19 18:20:28.759 25554 25554 D TooLargeTool: * android:support:fragments = 23.9 KB
12-19 18:20:28.759 25554 25554 D TooLargeTool: * android:view_state = 0.1 KB
12-19 18:20:28.759 25554 25554 D TooLargeTool: * android-support-nav:fragment:defaultHost = 0.1 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: MainActivity.onSaveInstanceState wrote: Bundle@143078438 contains 6 keys and measures 1,432.2 KB when serialized as a Parcel
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:fragments = 0.4 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:support:request_fragment_who = 0.1 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:support:fragments = 1,427.5 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:viewHierarchyState = 4.0 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:support:request_indicies = 0.1 KB
12-19 18:20:37.247 25554 25554 D TooLargeTool: * android:support:next_request_index = 0.1 KB
12-19 18:20:37.248 25554 25554 D TooLargeTool: BillingFragment.onSaveInstanceState wrote: Bundle@249100391 contains 0 keys and measures 0.0 KB when serialized as a Parcel
12-19 18:20:37.282 25554 25554 D TooLargeTool: NavHostFragment.onSaveInstanceState wrote: Bundle@79386132 contains 4 keys and measures 25.1 KB when serialized as a Parcel
12-19 18:20:37.282 25554 25554 D TooLargeTool: * android-support-nav:fragment:navControllerState = 0.9 KB
12-19 18:20:37.282 25554 25554 D TooLargeTool: * android:support:fragments = 23.9 KB
12-19 18:20:37.282 25554 25554 D TooLargeTool: * android:view_state = 0.1 KB
12-19 18:20:37.282 25554 25554 D TooLargeTool: * android-support-nav:fragment:defaultHost = 0.1 KB

屏幕与其他屏幕并没有太大区别，也没有什么特殊的例外。

我一直遇到这样的错误。

 java.lang.RuntimeException: android.os.TransactionTooLargeException: data parcel size 1432340 bytes
        at android.app.ActivityThread$StopInfo.run(ActivityThread.java:3781)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6119)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
     Caused by: android.os.TransactionTooLargeException: data parcel size 1432340 bytes
        at android.os.BinderProxy.transactNative(Native Method)
        at android.os.BinderProxy.transact(Binder.java:615)
        at android.app.ActivityManagerProxy.activityStopped(ActivityManagerNative.java:3636)
        at android.app.ActivityThread$StopInfo.run(ActivityThread.java:3773)

我有一个带有ImageView的自定义视图，并且我考虑过将该图像保存在Parcel中，如下所示：

internal class SavedState : ValidableTextInput.SavedState {

        var iconState : Drawable? = null

        constructor(superState: Parcelable) : super(superState) {}
        private constructor(parcel: Parcel) : super(parcel) {
            // order of reading must match order of writing
            val bitmap = parcel.readParcelable(javaClass.classLoader) as Bitmap
            this.iconState = BitmapDrawable(Resources.getSystem(), bitmap)
        }

        override fun writeToParcel(out: Parcel, flags: Int) {
            super.writeToParcel(out, flags)

            val bitmap = iconState?.toBitmap()
            out.writeParcelable(bitmap, flags)
        }

        companion object CREATOR : Parcelable.Creator<ValidableIconTextInput.SavedState> {
            override fun createFromParcel(parcel: Parcel): ValidableIconTextInput.SavedState {
                return ValidableIconTextInput.SavedState(parcel)
            }

            override fun newArray(size: Int): Array<ValidableIconTextInput.SavedState?> {
                return arrayOfNulls(size)
            }
        }
    }

- Michał Ziobro

---

是的，将位图写入保存的实例状态肯定会触发此问题。更好的策略是编写位图的标识符（文件名、URL等），然后在重新创建视图时重新加载位图。 - Ben P.

是的，但我已经尝试过删除此保存，例如将其注释掉或将视图的可见性设置为visibility="gone"，但没有任何变化。而且当ImageView中的图像更改时，最大事务的大小也不会改变。 - Michał Ziobro

这行代码难道不是导致错误的原因吗？12-19 18:20:28.735 25554 25554 D TooLargeTool: * android:support:fragments = 2,549.9 KB - Michał Ziobro

Answer 1

我发现我有SavedState的超类，然后我还将背景可绘制保存到包裹中。这明显引起了问题。

就像这里：

internal open class SavedState : View.BaseSavedState {

        var textInputState: String? = null
        var backgroundState: Drawable? = null

        constructor(superState: Parcelable) : super(superState) {}
        protected constructor(parcel: Parcel) : super(parcel) {
            // order of reading must match order of writing
            this.textInputState = parcel.readString()
            val bitmap = parcel.readParcelable(javaClass.classLoader) as Bitmap
            this.backgroundState = BitmapDrawable(Resources.getSystem(), bitmap)
        }

        override fun writeToParcel(out: Parcel, flags: Int) {
            super.writeToParcel(out, flags)
            // order of writing must match order of reading
            out.writeString(this.textInputState)
            val bitmap = backgroundState?.toBitmap()
            out.writeParcelable(bitmap, flags)
        }

        override fun describeContents(): Int {
            return 0
        }

        companion object CREATOR : Parcelable.Creator<SavedState> {
            override fun createFromParcel(parcel: Parcel): SavedState {
                return SavedState(parcel)
            }

            override fun newArray(size: Int): Array<SavedState?> {
               return arrayOfNulls(size)
            }
        }
    }

- Michał Ziobro