Question

所以我的问题是每当我尝试用一个按钮调用hostData数组时它返回null，但我知道它不是null。我甚至把一个debug.log调用update（）中的HostData数组的第一个成员，并获取当hostData！= null时它返回每一帧但是每当我从按钮调用它时它都是null，我甚至使用if（hostData） == null）来验证它。什么可能导致这种情况？

private HostData[] hostData;
private bool refreshing = false;
private Text joinServerText;
private GameObject joinServerButton;
private GameObject startServerButton;
private GameObject refreshServerButton;


void Awake()
{
    joinServerButton = GameObject.Find ("JoinServerButton");
    joinServerText = GameObject.Find("JoinServerText").GetComponent<Text>();
    startServerButton = GameObject.Find ("StartServerButton");
    refreshServerButton = GameObject.Find ("RefreshServerButton");
}

void Start()
{
    joinServerButton.SetActive (false);
}

void StartServer()
{
    bool useNat = !Network.HavePublicAddress();
    Network.InitializeServer(2,25000, !useNat);
    MasterServer.RegisterHost(gameName,"Tutorial Game Name","This is a    tutorial game");
}

void refreshHostList()
{
    MasterServer.RequestHostList(gameName);
    refreshing = true;
}

void Update()
{
    if (refreshing)
    {
        if(MasterServer.PollHostList().Length > 0)
        {
            refreshing = false;
            Debug.Log (MasterServer.PollHostList().Length);
            hostData = MasterServer.PollHostList();
        }
    }

    if(hostData != null)
    {
        joinServerButton.SetActive (true);
        joinServerText.text = hostData[0].gameName;
        Debug.Log ("hostData[0].gameName");
    }

}
//Messages
void OnServerInitialized()
{
    Debug.Log ("Server Initialized!");
}

void OnMasterServerEvent(MasterServerEvent mse)
{
    if(mse == MasterServerEvent.RegistrationSucceeded)
    {
        Debug.Log ("Registered Server");
    }
}

//UI
public void StartSeverButton()
{
    Debug.Log ("Starting Server...");
    StartServer();
}

public void RefreshHostsButton()
{
    Debug.Log ("Refreshing Hosts...");
    refreshHostList();      
}

public void JoinServerButton()
{

    //for(int i=0; i<hostData.Length; i++)
    //{ 
    if (hostData == null)  <--------- My problem
    {
        Debug.Log("hostData is null");
        //Debug.Log (hostData[0].gameName);
        //Network.Connect (hostData[0]);
    }

}
}

Answer 1

我通常通过替换它来解决神秘的错误值分配问题：

private HostData[] hostData;

有了这个：

private HostData[] _hostData;
private HostData[] hostData { get { return _hostData; } set { _hostData=value; Debug.Log("Host data set. Is null?: "+(_hostData == null), this); } }

运行它，您将立即看到变量何时设置为null。也许你会发现问题不是你想的 - 例如，它可能永远不会被设置，并且实际上有该类的多个实例，以及打印主机的实例count不是具有null变量的同一实例。

Unity HostData数组问题

1 个答案: