在我的internal Game class中，我既有a)定义了另一个嵌套的internal GamerTags class，又有b)定义了GamerTags[] _array变量。

在我的internal GamerTags class(嵌套类，为简单起见，我省略了它)中，我有一个readonly Hashtable。初始化后，当我尝试分配值时，仍然会收到null ref exception。我不是在更改指针，而是仅更改值，是否需要为Hastable添加另一个初始化？

internal class GamerTags
    {
        private readonly Hashtable _privateReadonlyHashTable;
        private string _json;
        private string _hash;

        internal IDictionary privateReadonlyHashTable
        {
            get
            {
                return this._privateReadonlyHashTable;
            }
        }

        internal string Hash
        {
            get
            {
                this.EnsureHash();
                return this._hash;
            }
        }           

        internal object this[string key]
        {
            get
            {
                return this._privateReadonlyHashTable[key];
            }
            set //throws an exception
            {
                this._privateReadonlyHashTable[key] = value;
            }
        }

        internal string Json
        {
            get
            {
                if (string.IsNullOrEmpty(this._json))
                {
                    this._json = myJsonSerializer.Serialize(this._privateReadonlyHashTable);
                }
                return this._json;
            }
        }

        internal int X
        {
            get;
            private set;
        }

        internal int Y
        {
            get;
            private set;
        }

        internal GamerTags(int x, int y)
        {
            this.X = x;
            this.Y = y;
        }

        private void EnsureHash()
        {
            bool flag = false;
            if (string.IsNullOrEmpty(this._hash))
            {
                if (flag)
                {
                    if (this.Json.Length < 100)
                    {
                        this._hash = this.Json;
                        return;
                    }
                    byte[] bytes = Encoding.ASCII.GetBytes(this.Json);
                    byte[] numArray = (new SHA1CryptoServiceProvider()).ComputeHash(bytes);
                    this._hash = Convert.ToBase64String(numArray);
                    return;
                }
                this._hash = this.FastHash();
            }
        }

        private string FastHash()
        {
            StringBuilder stringBuilder = new StringBuilder();
            foreach (string key in this._privateReadonlyHashTable.Keys)
            {
                stringBuilder.Append(key);
                stringBuilder.Append("_");
                stringBuilder.Append(this._privateReadonlyHashTable[key]);
                stringBuilder.Append("_");
            }
            return stringBuilder.ToString();
        }
    }
}

        int a = 2; int b = 0;
        GamerTags GamerTag = new Game.GamerTags(a, b);
        GamerTag["Fuel"] = "Loaded";              //throws an exception
        GamerTag["EngineStatus"] = (boolIsItOn ? 1 : 0); //throw an exception too

最佳答案

实际上，您需要实例化_privateReadonlyHashTable字段。

internal class GamerTags
{
    private readonly Hashtable _privateReadonlyHashTable =  new Hashtable();

    ..
    ..
}

https://stackoverflow.com/questions/29862688/