Question

我正在尝试使用Swift代码进行简单的DNS查找。到目前为止，我有

    if  host != "\0" {
        let hostRef = CFHostCreateWithName(kCFAllocatorDefault, host.bridgeToObjectiveC()).takeRetainedValue()
        var resolved = CFHostStartInfoResolution(hostRef, CFHostInfoType.Addresses, nil)
        let addresses = CFHostGetAddressing(hostRef, &resolved).takeRetainedValue() as NSArray

        for address: AnyObject in addresses {
            println(address)  // address is of type NSData.
        }
    }

根据Convert NSData to sockaddr struct in swift。（host是NSString。）

但是，在执行<10020000 4a7de064 00000000 00000000>语句并打印EXC_BAD_ACCESS (code=EXC_I386_GPFLT)数据后，我的调试器日志在第一行退出if之前打印address。我试图获取的是一个带有IP地址的字符串，或者如果主机不存在，则为空字符串。

Answer 1

我已经测试过，发现AnyObject已经崩溃了。你不需要AnyObject因为swift会从数组addresses中推断出类型

var host = "192.168.103.13"
    if  host != "\0" {
        let hostRef = CFHostCreateWithName(kCFAllocatorDefault, host.bridgeToObjectiveC()).takeRetainedValue()
        var resolved = CFHostStartInfoResolution(hostRef, CFHostInfoType.Addresses, nil)
        let addresses = CFHostGetAddressing(hostRef, &resolved).takeRetainedValue() as NSArray

        println(addresses)
        //Remove `AnyObject` as there is no need.Swift will infrence from array addresses
        for address in addresses {
            println(address)  // address is of type NSData.
        }
    }

在Swift中进行简单的DNS查找

1 个答案: