立即触发 addTextChangedListener

Question

我对 addTextChangedListener 有疑问。当我启动应用程序时（触摸屏幕后）立即触发 addTextChangedListener。

addTextChangedListener 在带有自定义适配器的回收视图中的 ViewHolder Class 中。

我尝试将 setOnClickListener1() 和 setOnClickListener2() 从 onBindViewHolder 移动到 onCreateViewHolder 但最糟糕的是（启动应用程序后立即触发）。

这是我的适配器代码

import android.text.Editable
import android.text.TextWatcher
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.EditText
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView

open class CustomAdapter(private val data: DataClass, private val activity: MainActivity) :
        RecyclerView.Adapter<CustomAdapter.ViewHolder>() {

    init {
        setHasStableIds(true)
    }


    override fun onCreateViewHolder(
            parent: ViewGroup,
            viewType: Int
    ): ViewHolder {

        val rowItem: View =
                LayoutInflater.from(parent.context).inflate(com.example.essai2.R.layout.list_item_view, parent, false)

        var myview= ViewHolder(rowItem)

      //myview.setOnClickListener1()
      //myview.setOnClickListener2()

        return myview


    }

    override fun onBindViewHolder(
            holder: ViewHolder,
            position: Int
    ) {

        holder.editText.setText(data.list1[position])
        holder.editText2.setText(data.list2[position])
        holder.textview.setText(data.list3[position])
        holder.setOnClickListener1()
        holder.setOnClickListener2()
    }

    override fun getItemId(position: Int): Long {
        return position.toLong()
    }

    override fun getItemCount(): Int {
        return data.list1.size
    }

   inner class ViewHolder(rowItem: View) : RecyclerView.ViewHolder(rowItem) {

        val textview : TextView = rowItem.findViewById(com.example.essai2.R.id.textview)
        val editText : EditText= rowItem.findViewById(com.example.essai2.R.id.editText)
        val editText2 : EditText= rowItem.findViewById(com.example.essai2.R.id.editText2)


        fun fonction3(position: Int)
        {
              if (position >=1 && position <=98) {
                  data.list3[position] = (0.5 * (data.list2[position - 1].toDouble() + data.list2[position + 1].toDouble())).toString()
                  //activity.Update()
              }
        }

        fun setOnClickListener1() {

            editText.addTextChangedListener(object : TextWatcher {

                override fun afterTextChanged(p0: Editable?) {
                   data.list1[getAdapterPosition()]= editText.text.toString()
                  // activity.fonction()
                }
                override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
                }
                override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
                }
            })
        }

        fun setOnClickListener2() {
            editText2.addTextChangedListener(object : TextWatcher {

                override fun afterTextChanged(p0: Editable?) {
                    data.list2[getAdapterPosition()] = editText2.text.toString()
                    activity.fonction2()
                    fonction3(getAdapterPosition())

                }
                override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
                }
                override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
                }
            })
        }
    }

}

这是我的 activity 代码

import android.os.Bundle
import android.widget.EditText
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.DividerItemDecoration
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val recyclerView = findViewById<RecyclerView>(R.id.recycler_view)
        recyclerView.layoutManager = LinearLayoutManager(this)

        recyclerView.adapter = CustomAdapter(DataClass(),this)

        recyclerView.addItemDecoration(DividerItemDecoration(this, DividerItemDecoration.VERTICAL))

        var textView2: TextView
        textView2 = findViewById(R.id.textView)
        var editText : EditText
    }

    fun Update()
    {
       // findViewById<RecyclerView>(R.id.recycler_view).getAdapter()?.notifyDataSetChanged()
        val recyclerView = findViewById<RecyclerView>(R.id.recycler_view)
        recyclerView.adapter=CustomAdapter(DataClass(),this)
        (recyclerView.adapter as CustomAdapter).notifyDataSetChanged()
    }


    fun fonction ()
    {
        var textView2: TextView
        textView2 = findViewById(R.id.textView)
        textView2.text="!!!!!!"
    }


    fun fonction2 ()
    {
        var textView2: TextView
        textView2 = findViewById(R.id.textView)
        textView2.text="?????"
    }

    private fun generateData(): List<String> {
        val data: MutableList<String> = ArrayList()
        for (i in 0..99) {
            data.add(i.toString() + "th Element")
        }
        return data
    }
}

class DataClass(){
    var list1: MutableList<String> = generateData2() as MutableList<String>
    var list2: MutableList<String> = generateData3() as MutableList<String>
    var list3: MutableList<String> = generateData4() as MutableList<String>

    private fun generateData2(): List<String> {
        val data: MutableList<String> = mutableListOf()
        for (i in 0..99) {
            data.add(i.toString())
        }
        return data
    }

    private fun generateData3(): List<String> {
        val data: MutableList<String> =mutableListOf()
        for (i in 0..99) {
            data.add((10*i).toString())
        }
        return data
    }

    private fun generateData4(): List<String> {
        val data: MutableList<String> = mutableListOf()
        for (i in 0..99) {
            data.add("none")
        }

        return data
    }

}

在此先感谢您的帮助

编辑：这里是 list_item_view.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        app:layout_constraintBottom_toBottomOf="parent"

        tools:ignore="MissingConstraints">

        <TextView
            android:id="@+id/textview2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="TextView"
            android:textSize="16dp" />

        <TextView
            android:id="@+id/textview"
            android:layout_width="wrap_content"
            android:layout_height="35dp"
            android:text="TextView"
            android:textSize="16dp" />


        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/editText2"
            android:layout_width="196dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:focusableInTouchMode="true"
            android:focusedByDefault="false"
            android:hint="hint" />

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/editText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:focusedByDefault="false"
            android:hint="hint" />

    </LinearLayout>



</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

您不应该在 onBindViewHolder 中添加 TextWatcher，因为每次 onBindViewHolder 调用时您都会向小部件添加多个侦听器。

在 onCreateViewHolder 中设置您的监听器以仅添加一个监听器，然后当您希望将 setText 设置为 EditText 时，您可以通过 setTag 来查看

editText.setTag("system input");

然后在侦听器中检查视图的标签以确定它是用户输入还是系统输入如果 tag=="system input" 完成你的工作并最终删除标签

view.setTag(null)

Answer 2

我刚刚根据下面的对话更改了我的答案。

首先，这是您的 XML 文件（我只是更改了视图的 ID，没有其他任何内容）：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        app:layout_constraintBottom_toBottomOf="parent"
        tools:ignore="MissingConstraints">

        <TextView
            android:id="@+id/tv2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="TextView2"
            android:textSize="16dp" />

        <TextView
            android:id="@+id/tv1"
            android:layout_width="wrap_content"
            android:layout_height="35dp"
            android:text="TextView1"
            android:textSize="16dp" />
        
        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/et2"
            android:layout_width="196dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:focusableInTouchMode="true"
            android:focusedByDefault="false"
            android:hint="hint" />

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/et1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:focusedByDefault="false"
            android:hint="hint" />

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

这是你的适配器（我检查了一切，没有错误）：

import android.content.Context
import android.text.Editable
import android.text.TextWatcher
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.list_item_view.view.*

class CustomAdapter(private val data : DataClass, private val context : Context) :
    RecyclerView.Adapter<CustomAdapter.ViewHolder>() {

    init {
        setHasStableIds(true)
    }


    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {

        val rowItem: View = LayoutInflater.from(context).inflate(R.layout.list_item_view, parent, false)

        return ViewHolder(rowItem)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {

        holder.itemView.tv1.setText(data.list3[position])

        holder.itemView.et1.setText(data.list1[position])
        holder.itemView.et2.setText(data.list2[position])

        holder.itemView.et1.addTextChangedListener(object : TextWatcher {

            override fun afterTextChanged(p0: Editable?) {
                data.list1[position]= holder.itemView.et1.text.toString()
                // activity.fonction()
            }
            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }
            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            }
        })
        holder.itemView.et2.addTextChangedListener(object : TextWatcher {

            override fun afterTextChanged(p0: Editable?) {
                data.list2[position] = holder.itemView.et2.text.toString()

                //this is instead of `fonction2()`
                holder.itemView.tv2.text = "?????"
                //fonction2()

                fonction3(position)
            }

            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            }
        })
    }

    override fun getItemId(position: Int): Long {
        return position.toLong()
    }

    override fun getItemCount(): Int {
        return data.list1.size
    }

    inner class ViewHolder(rowItem: View) : RecyclerView.ViewHolder(rowItem) {

    }

    fun fonction3(position: Int) {
        if (position in 1..98) {
            data.list3[position] = (0.5 * (data.list2[position - 1].toDouble() + data.list2[position + 1].toDouble())).toString()
            //activity.Update()
        }
    }
}

立即触发 addTextChangedListener

addTextChangedListener is triggered immediately

android

listener

textwatcher

kotlin

android-recyclerview