Question

以下教程可根据按钮单击更改设置视图。

当我在 onCreate 中设置变量时，不知何故，我无法在函数中引用它们。

abstract class MainActivity : AppCompatActivity() {

    var count = 0

    fun reset(view: View) {
        count = 0
        textView.setText(count.toString())
    }

    fun plusOne(view: View) {
        count++
        textView.setText(count.toString())
    }

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

        var textView = findViewById<TextView>(R.id.textView)
        textView.text = "Hello Fam"
    }
}

Answer 1

尝试使用以下代码。

abstract class MainActivity : AppCompatActivity() {
private lateinit var textView:TextView
var count = 0

fun reset(view: View) {
count = 0
textView.setText(count.toString())
}

fun plusOne(view: View) {
count++
textView.setText(count.toString())
}

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

textView = findViewById<TextView>(R.id.textView)
textView.text = "Hello Fam"
}
}

使用 Kotlin 时函数中未解析的引用 textView

1 个答案: