Java 如何检测用户'；在RecyclerView中输入EditText的值完成了吗？

我有一个包含编辑文本的recyclerview。只有在用户在任何编辑文本中输入金额后，我才能获得每个编辑文本的值，这样我才能更新总金额

我试图实现的是添加EditText的值并将其发送到活动。在活动中，我有“继续”按钮（我将在其中对总量执行一些验证）和总量文本视图（使用侦听器从recyclerview适配器检索）

我尝试使用

setOnEditorActionListener

，但如果用户单击“上一步”按钮而不是按enter键，这将不会有帮助

此外，我尝试使用焦点更改侦听器，但问题是即使在页面外部单击，EditText也不会失去焦点

当然，TextWatcher不是一个理想的解决方案，因为它在OnBindViewHolder中可能非常昂贵

我需要确保每当用户单击“继续”按钮时，总金额都会在之前更新。

Idea 最好的方法是添加两个通信（通过接口）：

• 在

  活动

  和

  适配器

• 在

  适配器

  和单个

  视窗夹之间的第二个
  
  

在添加此类通信后，您可以计算“实时”总数

解决方案 步骤#1 创建第一个

接口

，例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

并在活动中实现它或创建新变量（作为匿名类）

第2步 在创建适配器时传递您的活动（或上述接口的实例），例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

步骤3 创建第二个

接口

，例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

并在适配器中实现它或创建新变量（匿名类）-与步骤1中的相同

步骤4 绑定viewHolder时，传递适配器（或变量）和

位置（项目的），例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

步骤5
在
bind（）

在
PostTextChanged（）
方法（来自
TextWatcher
）中，从接口调用方法并传递新值。例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

要从
EditText
计算值，可以使用以下方法：

private fun getNumber(): Int =
    try {
        itemView.edit_text.text.toString().toInt()
    } catch (e: Exception) {
        0
    }

步骤6
在方法内更改文本时，您必须：


更新列表的内容


通知适配器“某些内容已更改”



例如：

interface AdapterContentChanged {
    fun valuesChanged()
}

private val ownAdapter = OwnAdapter(
    items,    // elements inside list
    this      // interface implementation
)

interface OwnViewHolderTextChanged {
    fun onTextChanged(position: Int, newValue: Int)
}

override fun onBindViewHolder(holder: OwnViewHolder, position: Int) {
    val number = list[position]
    holder.bind(number, position, this)
}

fun bind(
    // TODO - add here more information which you need,
    position: Int,
    listener: OwnViewHolderTextChanged
) {
    itemView.edit_text.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(s: Editable?) {
            // Get EditText content
            val newValue = getNumber()

            // Call method from interface
            listener.onTextChanged(position = position, newValue = newValue)
        }

        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            // Not used
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
            // Not used
        }

    })
}

override fun onTextChanged(position: Int, newValue: Int) {
    list[position] = newValue
    listener.valuesChanged()
}

步骤7
当某些内容发生变化时（Activty会知道这一点），您可以计算新的总和：

override fun valuesChanged() {
    val sum: Int = ownAdapter.getCurrentSum()
    text_view.text = "Sum:  $sum"
}

演示
Apt！很详细。我的解决方案有效吗？：）是的，博肯，你的解决方案正在发挥作用。谢谢