I have code:
package com.example.admin.maytinh
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import com.example.admin.maytinh.R.id.button
import com.example.admin.maytinh.R.id.editText
import com.example.admin.maytinh.R.id.editText2
import com.example.admin.maytinh.R.id.editText3
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
button.setOnClickListener(View.OnClickListener{xuly()})
}
public fun xuly(){
val a:Int = editText.text.ToString().ToInt()
val b:Int = editText2.text.ToString().ToInt()
val c:Int = a + b
editText3.text = c.ToString()
}
}
When i run it, i receive errors:
Anyone can explain for me why this is so and fix it Thank you
You importing ids, not views. Instead of:
import com.example.admin.maytinh.R.id.button
import com.example.admin.maytinh.R.id.editText
import com.example.admin.maytinh.R.id.editText2
import com.example.admin.maytinh.R.id.editText3
use this:
import kotlinx.android.synthetic.main.activity_main.*
and add plugin in app gradle file:
apply plugin: 'kotlin-android-extensions'
You got unresolved
error because you have not imported view. Instead of view you have imported ids.
There import To import single view
import kotlinx.android.synthetic.main.<layout_name>.<view_name>;
or
To import all widget properties for a specific layout
import kotlinx.android.synthetic.main.<layout>.*
Also you need is to enable the Android Extensions Gradle plugin in your module's build.gradle file:
apply plugin: 'kotlin-android-extensions'
It looks like you're trying to use Kotlin Android Extensions . To do so import:
import kotlinx.android.synthetic.main.activity_main.*
instead of
import com.example.admin.maytinh.R.id.button
import com.example.admin.maytinh.R.id.editText
import com.example.admin.maytinh.R.id.editText2
import com.example.admin.maytinh.R.id.editText3
Spend few minutes on reading how KAE work - it will help you a lot.
Moreover, there are no such methods as ToString()
and ToInt()
. What you're looking for is this: toString()
and toInt()
.
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