【正文】 specific position in the ArrayList. Both Remove and RemoveAt dissect only one element from the ArrayList at a time. We can remove a chunk of elements in one fell swoop by using the RemoveRange method. This method expects two parameters: an index to start at and a count of total elements to remove. Finally, to remove all the contents of an ArrayList, use the Clear method . Working with the Hashtable Class The type of collection most developers are used to working with is the hash table collection. Whereas the ArrayList indexes each element numerically, a hash table indexes each element by an alphanumeric key. The Collection data type in Visual Basic is a hash table。 各 集合類型的異同 因?yàn)槊總€(gè)集合有相同的基本功能，作為一個(gè)可變大小的存儲(chǔ)介質(zhì)對(duì)象的集合類型彼此有很多共同點(diǎn)，這并不奇怪。 添加，刪除和訪問隊(duì)列中的元素 隊(duì)列 的 先進(jìn)先出（ FIFO）的數(shù)據(jù)結(jié)構(gòu)通常被稱為第一，因?yàn)榈?n 個(gè) 元素插入刪除或訪問將是第n 個(gè)元素 ， 它有助于覺得作為一個(gè)人行隊(duì)列數(shù)據(jù)結(jié)構(gòu)。數(shù)組列表 的指標(biāo) 以 每個(gè)元素的數(shù)值 索引 ，而 哈希表 的每個(gè)元素用一個(gè)字母鍵索引。我們可以 使用移除 方法從一個(gè) 數(shù)組列表 刪除特定元素。與所有的集合 相比 ，我們將在這一章探討 的已 不再是一個(gè)問題。事實(shí)上 ,整個(gè)的命名空間系統(tǒng)集合是專門從事集合類型和輔助課程。 這些類型的集合都可以存儲(chǔ)對(duì)象類型的元素。 將元素添加到一個(gè) 數(shù)組列表 我們創(chuàng)建兩個(gè) 數(shù)組 類的實(shí)例， aTerritories 和 aStates，上線分別為 5 和 6。如果 你 嘗試刪除一個(gè)元素不存在，將拋出 路徑 異 常問題。適用于 數(shù)組列表 的每個(gè)元 素的順序，根據(jù)其數(shù)值指標(biāo) 。 有兩部分到隊(duì)列中有任何線兩部分組成 :尾部的隊(duì)列，在新的路線的人開始等待，隊(duì)列的頭，線下的人在那里等待被送達(dá)。 他們 都從集合中添加和刪除元素的方法。 6 原文： Common Code Techniques : Tips, Tutorials,and Code— Scott Mitchell Using Collections Most modern programming languages provide support for some type of object that can hold a variable number of elements. These objects are referred to as collections, and they can have elements added and removed with ease without having to worry about proper memory you’ve programmed with classic ASP before, you’re probably familiar with the object, a collection object that references each element with a textual key. A collection that stores objects in this fashion is known as a hash table. There are many types of collections in addition to the hash table. Each type of collection is similar in purpose: it serves as a means to store a varying number of elements, providing an easy way, at a minimum, to add and remove elements. Each different type of collection is unique in its method of storing, retrieving, and referencing its various elements. The .NET Framework provides a number of collection types for the developer to use. In fact, an entire namespace, , is dedicated to collection types and helper classes. Each of these collection types can store elements of type Object. Because in .NET all primitive data types—string, integers, date/times, arrays, and so on—are derived from the Object class, these collections can literally store anything! For example, you could use a single collection to store a couple of integers, an instance of a classic COM ponent, a string, a date/time, and two instances of a customwritten .NET ponent. Most of the examples in this section use collections to house primitive data types (strings, integers, doubles). However, Illustrates a collection of collections—that is, a collection type that stores entire collections as each of its elements! Throughout this section we’ll examine five collections the .NET Framework offers developers: the ArrayList, the Hashtable, the SortedList, the Queue, and the Stack. As you study each of these collections, realize that they all have many similarities. For example, each type of collection can be iterated through elementbyelement using a For Each ... Next loop in VB (or a foreach loop in C). Each collection type has a number of similarly named functions that perform the same tasks. For example, each collection type