Kotlin相当于检查是否为空

Question

以下代码段可以使用!或?运营商在Kotlin中以较短的形式编写:

val acct: GoogleSignInAccount?  = result.signInAccount
if (acct != null && acct.displayName != null)
    MagicToast.showSuccess(this, "Account Name: " + acct.displayName)

Answer 1

acct?.displayName?.let {
    MagicToast.showSuccess(this, "Account Name: $it")
}

根据您的使用情况,acct可能会被替换result.signInAccount.