在回收器视图适配器android Kotlin之外更新ProgressBar

// 在Activity或Fragment中
class MyActivity : AppCompatActivity() {
    private lateinit var progressBar: ProgressBar
    private val handler = Handler(Looper.getMainLooper())

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

        progressBar = findViewById(R.id.progressBar)

        // 启动耗时操作
        startLongRunningTask()
    }

    private fun startLongRunningTask() {
        // 显示进度条
        progressBar.visibility = View.VISIBLE

        // 在后台线程进行耗时操作
        Thread {
            // 模拟耗时操作
            Thread.sleep(5000)

            // 更新UI线程的ProgressBar
            handler.post {
                progressBar.visibility = View.GONE
            }
        }.start()
    }
}