使用Kotlin的简单出生年份计算器

Question

我开始做一个简单的android应用程序，练习用Kotlin编程语言计算年龄，错误来自34行，有人能帮我解决这个问题并修复它吗？因为我只是的初学者

package com.calcult.age.agecalcult
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
import java.util.*
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
var my_age_number =  ageText.text!!
var my_month_number =  ageText2.text!!
var my_day_number =  ageText3.text!!
var calcult_age_button = doIT
calcult_age_button.setOnClickListener {
if(my_age_number.isEmpty()){
Toast.makeText(this,"ادخل سنه ميلادك !",Toast.LENGTH_LONG).show()
}else if (my_age_number.length < 4 || my_age_number.length > 4){
Toast.makeText(this,"ادخل سنه ميلاديه صالحه الأستعمال !",Toast.LENGTH_LONG).show()
}else if (my_age_number.length == 4){
fun getAge(){
val get_the_year = Calendar.getInstance().get(Calendar.YEAR);
val calculat_the_age = my_age_number - get_the_year

}
}
}
}
}

Answer 1

my_age_number是一个字符串值，因此您应该尝试

var calculat_the_age: Int? = null
try {
calculat_the_age = my_age_number.toInt() - Calendar.getInstance().get(Calendar.YEAR)
} catch (ex: NumberFormatException) {
// my_age_number not a number
}

希望这能有所帮助！