DictionaryBase.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Collections / DictionaryBase.cs / 1 / DictionaryBase.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
//------------------------------------------------------------------------------
//----------------------------------------------------------------------------- 
 
namespace System.Collections {
 
    using System;
    using System.Security.Permissions;

    // Useful base class for typed read/write collections where items derive from object 
    [Serializable]
[System.Runtime.InteropServices.ComVisible(true)] 
    public abstract class DictionaryBase : IDictionary { 
        Hashtable hashtable;
 
        protected Hashtable InnerHashtable {
            get {
                if (hashtable == null)
                    hashtable = new Hashtable(); 
                return hashtable;
            } 
        } 

        protected IDictionary Dictionary { 
            get { return (IDictionary) this; }
        }

        public int Count { 
            // to avoid newing inner list if no items are ever added
            get { return hashtable == null ? 0 : hashtable.Count; } 
        } 

        bool IDictionary.IsReadOnly { 
            get { return InnerHashtable.IsReadOnly; }
        }

        bool IDictionary.IsFixedSize { 
            get { return InnerHashtable.IsFixedSize; }
        } 
 
        bool ICollection.IsSynchronized {
            get { return InnerHashtable.IsSynchronized; } 
        }

        ICollection IDictionary.Keys {
            get { 
                return InnerHashtable.Keys;
            } 
        } 

        Object ICollection.SyncRoot { 
            get { return InnerHashtable.SyncRoot; }
        }

        ICollection IDictionary.Values { 
            get {
                return InnerHashtable.Values; 
            } 
        }
 
        public void CopyTo(Array array, int index) {
            InnerHashtable.CopyTo(array, index);
        }
 
        object IDictionary.this[object key] {
            get { 
                object currentValue = InnerHashtable[key]; 
                OnGet(key, currentValue);
                return currentValue; 
            }
            set {
                OnValidate(key, value);
                bool keyExists = true; 
                Object temp = InnerHashtable[key];
                if( temp == null) { 
                    keyExists = InnerHashtable.Contains(key); 
                }
 
                OnSet(key, temp, value);
                InnerHashtable[key] = value;
                try {
                    OnSetComplete(key, temp, value); 
                }
                catch { 
                   if( keyExists) { 
                       InnerHashtable[key] = temp;
                   } 
                   else {
                       InnerHashtable.Remove(key);
                   }
                   throw; 
                }
            } 
        } 

        bool IDictionary.Contains(object key) { 
            return InnerHashtable.Contains(key);
        }

        void IDictionary.Add(object key, object value) { 
            OnValidate(key, value);
            OnInsert(key, value); 
            InnerHashtable.Add(key, value); 
            try {
                OnInsertComplete(key, value); 
            }
            catch {
                InnerHashtable.Remove(key);
                throw; 
            }
        } 
 
        public void Clear() {
            OnClear(); 
            InnerHashtable.Clear();
            OnClearComplete();
        }
 
        void IDictionary.Remove(object key) {
            if(InnerHashtable.Contains(key)) { 
                Object temp = InnerHashtable[key]; 
                OnValidate(key, temp);
                OnRemove(key, temp); 

                InnerHashtable.Remove(key);
                try {
                    OnRemoveComplete(key, temp); 
                }
                catch { 
                    InnerHashtable.Add(key, temp); 
                    throw;
                } 
            }
        }

        public IDictionaryEnumerator GetEnumerator() { 
            return InnerHashtable.GetEnumerator();
        } 
 
        IEnumerator IEnumerable.GetEnumerator() {
            return InnerHashtable.GetEnumerator(); 
        }

        protected virtual object OnGet(object key, object currentValue) {
            return currentValue; 
        }
 
        protected virtual void OnSet(object key, object oldValue, object newValue) { 
        }
 
        protected virtual void OnInsert(object key, object value) {
        }

        protected virtual void OnClear() { 
        }
 
        protected virtual void OnRemove(object key, object value) { 
        }
 
        protected virtual void OnValidate(object key, object value) {
        }

        protected virtual void OnSetComplete(object key, object oldValue, object newValue) { 
        }
 
        protected virtual void OnInsertComplete(object key, object value) { 
        }
 
        protected virtual void OnClearComplete() {
        }

        protected virtual void OnRemoveComplete(object key, object value) { 
        }
 
    } 

}

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