弹出片段后，所有Editexts都将替换为相同的值 [英] All Editexts be replace by same value after pop a Fragment

问题描述

我有一个奇怪的问题，我有2个片段，在第一个片段中，我有一些自定义EditText，还有一个按钮将其替换为第二个片段(addToBackStack = true)，然后在第二个片段中，我尝试使用popBackStack()返回第一个片段，就会出现此问题，所有自定义EditText都具有相同的值.

I have a strange issue, I have 2 fragment, in first fragment, I have some custom EditText, and a button to replace this by second fragment (addToBackStack = true), then, in second fragment, I try to using popBackStack() to back to first fragment, the issue occur, all custom EditText have same value.

下面是我的所有代码

FirstFragment

class FirstFragment : BaseFragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_first, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        btn_next.setOnClickListener {
            val transaction = requireActivity().supportFragmentManager!!.beginTransaction()
                .replace(R.id.contentFrame, SecondFragment(), "")
            commitTransaction(transaction, true, -1)
        }
    }
}

SecondFragment

class SecondFragment : BaseFragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_second, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        btn_back.setOnClickListener {
            requireActivity().supportFragmentManager.popBackStack()
        }
    }
}

fragment_first.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <com.sogia.replacefragmentdemo.CustomView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

    <com.sogia.replacefragmentdemo.CustomView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <Button
        android:id="@+id/btn_next"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="next"
        />
</LinearLayout>

fragment_second.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <Button
        android:id="@+id/btn_back"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="back"
        />
</LinearLayout>

CustomView

class CustomView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : LinearLayout(context, attrs, defStyleAttr) {
    init {
        inflate(context, R.layout.layout_custom_view, this)
    }
}

layout_custom_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    >
    <EditText
        android:id="@+id/edt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="input something"
        />
</LinearLayout>

任何答复将不胜感激.

推荐答案

最后，我找出了根本原因和解决方案， 感谢@abhradeep ghosh，@ Eselfar，@ MadScientist和另一位回复此帖子的人.

Finally I find out the root cause and the solution, Thanks @abhradeep ghosh, @Eselfar, @MadScientist and another one else who response this post.

原因:视图ID应该是唯一的！否则，您的状态将被另一个具有相同ID的视图覆盖.在我的情况下，我有2个ID为@id/edt的视图，因此我的状态容器仅包含1个实例-以状态存储过程中最后一个为准.

Cause: view IDs should be unique! Otherwise your state will be overwritten by another view with the same ID. In my case I have 2 views with id @id/edt, so my states container holds only 1 instance of it - whichever came last during state store process.

这是我的解决方法，(来自这篇文章)，

Here is my solution, (from this post),

首先，为保存视图状态创建新的类

First, create new class for save sate of view

class SavedState(superState: Parcelable) : View.BaseSavedState(superState) {
    var childrenStates: SparseArray<Any>? = null

    override fun writeToParcel(out: Parcel, flags: Int) {
        super.writeToParcel(out, flags)
        childrenStates?.let {
            out.writeSparseArray(it)
        }
    }
}

在我的CustomView

@Suppress("UNCHECKED_CAST")
    public override fun onSaveInstanceState(): Parcelable? {
        val superState = super.onSaveInstanceState()
        val ss = SavedState(superState)
        ss.childrenStates = SparseArray()
        for (i in 0 until childCount) {
            getChildAt(i).saveHierarchyState(ss.childrenStates as SparseArray<Parcelable>)
        }
        return ss
    }

    @Suppress("UNCHECKED_CAST")
    public override fun onRestoreInstanceState(state: Parcelable) {
        val ss = state as SavedState
        super.onRestoreInstanceState(ss.superState)
        for (i in 0 until childCount) {
            getChildAt(i).restoreHierarchyState(ss.childrenStates as SparseArray<Parcelable>)
        }
    }

    override fun dispatchSaveInstanceState(container: SparseArray<Parcelable>) {
        dispatchFreezeSelfOnly(container)
    }

    override fun dispatchRestoreInstanceState(container: SparseArray<Parcelable>) {
        dispatchThawSelfOnly(container)
    }

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