data-binding - Kotlin 2路绑定(bind)自定义 View

Question

我有 1 个自定义 View ，它扩展了 ConstraintLayout 并包含 1 个 EditText 和 2 个 TextViews

在我的自定义 View 中，我定义了这个 attr (和其他):

<attr name="Text" format="string" />

我像这样使用它:

app:Text="@={login.email}"

在我的自定义 View 中，我定义:

  companion object {
    @JvmStatic @BindingAdapter("Text")
    fun setText(nMe : View, nText: String) {
        nMe.nInput.setText(nText)
    }
    @InverseBindingAdapter(attribute = "Text")
    fun getText(nMe : View) : String {
      return  nMe.nInput.text.toString()
    }

女巫在单向绑定(bind)中工作正常

app:Text="@{login.email}"

但是当我尝试在双向绑定(bind)中使用它时，我得到指向 ActivityLoginBinding.java java.lang.String callbackArg_0 = mBindingComponent.null.getText(mEmail); 的错误。

怎么做才能获得2路绑定(bind)？

乐 :经过一些研究，我最终得到了这个:

@InverseBindingMethods(InverseBindingMethod(type = 
CustomInput::class,attribute = "bind:Text",event = 
"bind:textAttrChanged",method = "bind:getText"))
class CustomEditTextBinder {
companion object {
    @JvmStatic
    @BindingAdapter(value = ["textAttrChanged"])
    fun setListener(editText: CustomInput, listener: InverseBindingListener?) {
        if (listener != null) {
            editText.nInput.addTextChangedListener(object : TextWatcher {
                override fun beforeTextChanged(charSequence: CharSequence, i: Int, i1: Int, i2: Int) {

                }

                override fun onTextChanged(charSequence: CharSequence, i: Int, i1: Int, i2: Int) {

                }

                override fun afterTextChanged(editable: Editable) {
                    listener.onChange()
                }
            })
        }
    }

    @JvmStatic
    @InverseBindingAdapter(attribute = "Text")
    fun getText(nMe: CustomInput): String {
        return nMe.nInput.text.toString()
    }

    @JvmStatic
    @BindingAdapter("Text")
    fun setText(editText: CustomInput, text: String?) {
        text?.let {
            if (it != editText.nInput.text.toString()) {
                editText.nInput.setText(it)
            }
        }
    }
}

}

但现在我得到:
找不到事件 TextAttrChanged

Answer 1

我想你只需要event = "android:textAttrChanged" .
这对我有用(将文本设置为空 String 如果它是 0):

object DataBindingUtil {
    @BindingAdapter("emptyIfZeroText")
    @JvmStatic
    fun setText(editText: EditText, text: String?) {
        if (text == "0" || text == "0.0") editText.setText("") else editText.setText(text)
    }

    @InverseBindingAdapter(attribute = "emptyIfZeroText", event = "android:textAttrChanged")
    @JvmStatic
    fun getText(editText: EditText) = editText.text.toString()
}