小编Max*_*nik的帖子

我想在Xamarin Studio中使用.net 4.5.2框架编译c＃项目。当我打开项目并寻找目标框架时，有.NET Framework 4.5.2（未安装）。因此它不会编译。有没有办法在Mac OS X上安装.net Framework 4.5.2或更高版本？

我是 RxJava2 的新手。

我有下一个代码：

fun signIn(): Completable = getCredentials() // get saved token
        .onErrorResumeNext { makeLockSignInRequest() } // if token not saved then get it
        .flatMap { refreshToken(it) } // refresh token
        .doOnSuccess { credentialsManager.saveCredentials(it) } // save updated token
        .doFinally { lock?.onDestroy(context) }!!
        .toCompletable()

private fun getCredentials() = Single.create(SingleOnSubscribe<Credentials> {
    credentialsManager.getCredentials(object : BaseCallback<Credentials, CredentialsManagerException> {
        override fun onSuccess(payload: Credentials?) = it.onSuccess(payload!!)
        override fun onFailure(error: CredentialsManagerException?) = it.onError(error!!)
    })
})

private fun makeLockSignInRequest() = Single.create(SingleOnSubscribe<Credentials> {
    lock = Lock.newBuilder(auth0, object …