ブログ

<com.google.android.material.textfield.TextInputLayout
    android:id="@+id/cost_of_service"
    android:layout_width="160dp"
    android:layout_height="wrap_content"
    android:hint="@string/cost_of_service"
    android:inputType="numberDecimal"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" >

    <com.google.android.material.textfield.TextInputEditText
        android:id="@+id/cost_of_service_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal" />

</com.google.android.material.textfield.TextInputLayout>

    private fun setErrorTextField(error: Boolean) {
        if (error) {
            binding.textField.isErrorEnabled = true
            binding.textField.error = getString(R.string.try_again)
        } else {
            binding.textField.isErrorEnabled = false
            binding.textInputEditText.text = null
        }
    }