java.lang.IllegalStateException：活动已被销毁（替换片段时）

Question

我在LoginActivity中使用两个片段登录片段和寄存器片段

在活动加载时，调用登录片段并且没有问题 当我尝试将loginFragment替换为registerFragment时，我遇到了以下崩溃：

Process: symphony.vnet.acube.com.symphonyupdated, PID: 28073
    java.lang.IllegalStateException: Activity has been destroyed
        at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:2087)
        at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:678)
        at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:632)
        at com.vnet.acube.com.vnetinc.acitivity.helper.AcitivityExtensionsKt.addFragment(AcitivityExtensions.kt:16)
        at com.vnet.acube.com.vnetinc.acitivity.loginRegister.LoginActivity.openRegisterFragment(LoginActivity.kt:38)
        at com.vnet.acube.com.vnetinc.acitivity.loginRegister.LoginFragment.onClick(LoginFragment.kt:27)
        at android.view.View.performClick(View.java:5265)
        at android.view.View$PerformClick.run(View.java:21534)
        at android.os.Handler.handleCallback(Handler.java:815)
        at android.os.Handler.dispatchMessage(Handler.java:104)
        at android.os.Looper.loop(Looper.java:207)
        at android.app.ActivityThread.main(ActivityThread.java:5737)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679)

这是我的代码：

登录活动：

class LoginActivity : AppCompatActivity() {



    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        if(savedInstanceState==null)
        {
            addFragment(LoginFragment.newInstance(),R.id.details_fragment)
        }
    }

    public fun openLoginFragment() {
        replaceFragment(LoginFragment.newInstance(),R.id.details_fragment)
    }


    override fun onBackPressed()
    {
    }

    public fun openRegisterFragment(){
      replaceFragment(RegisterFragment.newInstance(),R.id.details_fragment)
    }
}

登录片段：

class LoginFragment : Fragment(),View.OnClickListener  {

    override fun onClick(p0: View?) {
        if(p0!!.id == R.id.tvNewUser)
        {
            var loginActivity:LoginActivity = LoginActivity()
            loginActivity.openRegisterFragment()
        }
    }
    companion object {
        fun newInstance():LoginFragment{
            return LoginFragment()
        }
    }
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        // Inflate the layout for this fragment

        var view:View =  inflater.inflate(R.layout.fragment_login, container, false)
        return view
    }
}

注册片段

class RegisterFragment : Fragment() {
        companion object {
            fun newInstance(): RegisterFragment
            {
                return RegisterFragment()
            }
        }
        override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                                  savedInstanceState: Bundle?): View? {
            // Inflate the layout for this fragment
            return inflater.inflate(R.layout.fragment_register, container, false)
        }


    }

能力扩展

inline fun FragmentManager.inTransaction(func: FragmentTransaction.()->FragmentTransaction)
{
    beginTransaction().func().commit()
}

fun AppCompatActivity.addFragment(fragment: Fragment, frameId:Int)
{
    supportFragmentManager.inTransaction { add(frameId,fragment) }
}
fun AppCompatActivity.replaceFragment(fragment: Fragment,frameId: Int)
{
    supportFragmentManager.inTransaction { replace(frameId,fragment) }
}