Android 在Kotlin中，如何将片段传递给FragmentManager.replace

在最后一种方法中，我得到

Type mismatch: inferred type is android.support.v4.app.Fragment 
but android.app.Fragment! was expected

我不确定如何在科特林解决这个问题

var fragment: Fragment = null
var fragmentClass: Class<*>? = null
fragmentClass = CardBackFragment::class.java
try {
    fragment = fragmentClass!!.newInstance() as Fragment
} catch (e: Exception) {
    e.printStackTrace()
}

fragmentManager
        .beginTransaction()
        .replace(R.id.flContent, fragment)

---

您需要使用supportFragmentManager，而不是使用fragmentManager