适用于Unity3d Android ValueChanged的Firebase数据库取消订阅问题 [英] Firebase Database for Unity3d Android ValueChanged unsubscribe issues

问题描述

我对Unity3d SDK有问题. 我订阅ValueChanged事件，并在第一次调用它时取消订阅处理程序. 在Unity中，一切正常. 但是，当我为Android构建项目时，取消订阅失败:取消订阅后，我仍然在处理程序中处理事件. 这是代码:

I have problem with Unity3d SDK. I subscribe to ValueChanged event and when first time it invokes I unsubscribe from the handler. In Unity everything works fine. But when I build project for Android, unsubscribe fails: after unsubscribe I still handle events in handler. Here is the code:

public void CheckUserExists()
{
    FirebaseDatabase.DefaultInstance
        .GetReference("users").Child(primary_key)
        .ValueChanged += CheckUserExistsHadler;
}

void CheckUserExistsHadler(object sender, ValueChangedEventArgs e)
{
    FirebaseDatabase.DefaultInstance
        .GetReference("users").Child(primary_key)
        .ValueChanged -= CheckUserExistsHadler;

    if (e.Snapshot == null || e.Snapshot.Value == null)
    {
        print("user_exists");
    }
    else
    {
        print("user_not_exists");
    }
}

推荐答案

感谢小费.我改为

user_reference = FirebaseDatabase.DefaultInstance.GetReference("users").Child(primary_key); 
...
user_reference.ValueChanged += CheckUserExistsHadler; 
...
user_reference.ValueChanged -= CheckUserExistsHadler; 

效果很好

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