点击按钮时setOnClickListener不起作用

Question

所以我尝试使用 Kotlin 在 Android Studio 中构建一个小型计算器应用程序。 当用户按下添加按钮时，应该计算两个数字并将其显示在文本视图中，但是当我按下按钮时什么也没有发生。请帮忙

fun addition()
    {
 val num1 = findViewById<EditText>(R.id.numberFirst)
 val num2 = findViewById<EditText>(R.id.numberSecond)
 val buttonAdd = findViewById<Button>(R.id.addButton)
 val result = findViewById<TextView>(R.id.resultView)

 buttonAdd.setOnClickListener {
 val addNum1 = num1.text.toString().toInt()
 val addNum2 = num2.text.toString().toInt()
 val sum = addNum1 + addNum2
 result.setText("$sum")
  }
   }

Answer 1

试试这个>

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main) 

    addButton.setOnClickListener {
        addition() 
    }
}

fun addition() {
    val num1Text = numberFirst.text.toString()  
    val num2Text = numberSecond.text.toString() 

    // Check if the input is empty
    if (num1Text.isEmpty() || num2Text.isEmpty()) {
        resultView.text = "Please enter valid numbers" 
        return
    }

    // Convert the input to integers and perform addition
    val num1 = num1Text.toInt()
    val num2 = num2Text.toInt()
    val sum = num1 + num2

    resultView.text = "Result: $sum" // Display the result in the TextView
  }
}