如何在安卓中为动态多于编辑文本设置一个文本观察器

Question

我想为动态而不是编辑文本设置一个文本观察器.如果我正在创建动态编辑文本，我想对所有动态编辑文本使用一个文本观察器.如果有人知道告诉我

Answer 1

您可以为编辑文本创建自定义文本观察程序类

class DynamicTextWatcher(private val editText: EditText, private val type: String) :
TextWatcher {
var beforeText : String = ""
override fun beforeTextChanged(p0: CharSequence?, start: Int, before: Int, count: Int) {
    beforeText = p0.toString()
}
override fun onTextChanged(p0: CharSequence?, start: Int, before: Int, count: Int) {
    if (p0 == null)
        return
    // 1. get cursor position : p0 = start + before
    val initialCursorPosition = start + before
    //2. get digit count after cursor position : c0
    val numOfDigitsToRightOfCursor = getNumberOfDigits(beforeText.substring(initialCursorPosition,
        beforeText.length))
    try {
        editText.removeTextChangedListener(this)
        val value = editText.text.toString().trimStart(' ')
        if (value != "") {
            when(type){
                Constants.FORM_INPUT_NAME -> {
                    //editText.setText(value.replaceFirstChar { it.uppercase() })
                    val fc = value[0]
                    if (fc == ' '){
                        editText.setText(value.drop(1))
                    }else{
                        if (value.contains("  ")){
                            editText.setText(value.replace("  ", " "))
                        }
                        else {
                            editText.setText(value)
                        }
                    }
                }
                Constants.FORM_INPUT_NO_SPACE -> editText.setText(value.removeWhitespaces())
                Constants.FORM_INPUT_MOBILE -> {
                    val cs = value.removeWhitespaces()
                    val cleanString = cs.replace("[^0-9]".toRegex(), "")
                    editText.setText(cleanString)
                }
                //Constants.FORM_INPUT_PASSWORD -> editText.setText(value.removeWhitespaces())
            }
        }else{
            editText.setText(value)
        }
        editText.setSelection(getNewCursorPosition(numOfDigitsToRightOfCursor, value,type))
        editText.addTextChangedListener(this)
    } catch (ex: Exception) {
        ex.printStackTrace()
        editText.addTextChangedListener(this)
    }
}
override fun afterTextChanged(s: Editable) {
}
private fun getNewCursorPosition(digitCountToRightOfCursor : Int, numberString : String, type : String) : Int{
    Log.v("getNewCursorPosition","hello"+numberString+"hello")
    var position = 0
    var c = digitCountToRightOfCursor
    var value =  numberString
    when(type){
        Constants.FORM_INPUT_NAME -> {
            if (numberString.contains("  ")){
                value =  numberString.replace("  ", " ")
            }
        }
        Constants.FORM_INPUT_NO_SPACE -> value = numberString.removeWhitespaces()
        Constants.FORM_INPUT_MOBILE -> { }
    }
    for (i in value.reversed()) {
        if (c == 0)
            break
        else
            c --
        position ++
    }
    return value.length - position
}
private fun getNumberOfDigits(@NonNull text : String) : Int{
    var count = 0
    for (i in text)
            count++
    return count
}

}

活动中显示的代码

registerSheetBinding.etPassword.addTextChangedListener(
        DynamicTextWatcher(
            registerSheetBinding.etPassword,
            Constants.FORM_INPUT_NO_SPACE
        )
    )
    registerSheetBinding.etEmail.addTextChangedListener(
        DynamicTextWatcher(
            registerSheetBinding.etEmail,
            Constants.FORM_INPUT_NO_SPACE
        )
    )
    registerSheetBinding.etFullName.addTextChangedListener(
        DynamicTextWatcher(
            registerSheetBinding.etFullName,
            Constants.FORM_INPUT_NAME
        )
    )

我希望这段代码对您有所帮助。#Android 开发者

Answer 2

您可以

创建自定义的TextWatcher类，如下所示。

private class CustomTextWatcher implements TextWatcher{
        private EditText et;
        private CustomTextWatcher (EditText et){
            this.et = et;
        }
        @Override
        public void afterTextChanged(Editable s) {
        }
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
        }
        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {

        }
    }

要设置文本观察器，您可以执行以下操作

yourdynamicedittext.addTextChangedListener(new CustomTextWatcher(yourdynamicedittext));

在 CustomTextWatcher 类中，您可以处理分配给 TextChangedListener 的每个编辑文本的相对大小写。为了识别不同的编辑文本，您可以在CustomTextWatcher类中设置标签并检索它。

yourdynamicedittext.setTag（1， 2， ...n）;