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7.声明和使用枚举 ' Declare the Enumeration Public Enum MessageSize Small = 0 Medium = 1 Large = 2 End Enum ' Create a Field or Property Public MsgSize As MessageSize ' Assign to the property using the Enumeration values MsgSize = small // Declare the Enumeration public enum MessageSize { Small = 0, Medium = 1, Large = 2 } // Create a Field or Property public var msgsize:MessageSize; // Assign to the property using the Enumeration values msgsize = Small; 8.声明和使用方法 ' Declare a void return function Sub VoidFunction() ... End Sub ' Declare a function that returns a value Function StringFunction() As String ... Return CStr(val) End Function ' Declare a function that takes and returns values Function ParmFunction(a As String, b As String) As String ... Return CStr(A & B) End Function ' Use the Functions VoidFunction() Dim s1 As String = StringFunction() Dim s2 As String = ParmFunction("Hello", "World!") // Declare a void return function function voidfunction() : void { ... } // Declare a function that returns a value function stringfunction() : String { ... return String(val); } // Declare a function that takes and returns values function parmfunction(a:String, b:String) : String { ... return String(a + b); } // Use the Functions voidfunction(); var s1:String = stringfunction(); var s2:String = parmfunction("Hello", "World!"); 9.数组 Dim a(2) As String a(0) = "1" a(1) = "2" a(2) = "3" Dim a(2,2) As String a(0,0) = "1" a(1,0) = "2" a(2,0) = "3" var a : String[] = new String[3]; a[0] = "1"; a[1] = "2"; a[2] = "3"; var a : String[][] = new String[3][3]; a[0][0] = "1"; a[1][0] = "2"; a[2][0] = "3"; 10.初始化 Dim s As String = "Hello World" Dim i As Integer = 1 Dim a() As Double = { 3.00, 4.00, 5.00 } var s : String = "Hello World"; var i : int = 1; var a : double[] = [ 3.00, 4.00, 5.00 ]; 11.If 语句 if (Request.QueryString != null) { ... } If Not (Request.QueryString = Nothing) ... End If if (Request.QueryString != null) { ... } 12.Case 语句 switch (FirstName) { case "John" : ... break; case "Paul" : ... break; case "Ringo" : ... break; default: ... break; } Select Case FirstName Case "John" ... Case "Paul" ... Case "Ringo" ... Case Else ... End Select switch (FirstName) { case "John" : ... break; case "Paul" : ... break; case "Ringo" : ... break; default: ... break; }

13.For 循环 for (int i=0; i<3; i++) a(i) = "test"; Dim I As Integer For I = 0 To 2 a(I) = "test" Next for (var i : int = 0; i < 3; i++) a[i] = "test"; 14.While 循环 int i = 0; while (i<3) { Console.WriteLine(i.ToString()); i += 1; } Dim I As Integer I = 0 Do While I < 3 Console.WriteLine(I.ToString()) I += 1 Loop var i : int = 0; while (i < 3) { Console.WriteLine(i); i += 1; } 15.异常处理 try { // Code that throws exceptions } catch(OverflowException e) { // Catch a specific exception } catch(Exception e) { // Catch the generic exceptions } finally { // Execute some cleanup code } Try ' Code that throws exceptions Catch E As OverflowException ' Catch a specific exception Catch E As Exception ' Catch the generic exceptions Finally ' Execute some cleanup code End Try try { // Code that throws exceptions } catch(e:OverflowException) { // Catch a specific exception } catch(e:Exception) { // Catch the generic exceptions } finally { // Execute some cleanup code } 16.字符串连接 // Using Strings String s1; String s2 = "hello"; s2 += " world"; s1 = s2 + " !!!"; // Using StringBuilder class for performance StringBuilder s3 = new StringBuilder(); s3.Append("hello"); s3.Append(" world"); s3.Append(" !!!"); ' Using Strings Dim s1, s2 As String s2 = "hello" s2 &= " world" s1 = s2 & " !!!" ' Using StringBuilder class for performance Dim s3 As New StringBuilder() s3.Append("hello") s3.Append(" world") s3.Append(" !!!") // Using Strings var s1 : String; var s2 : String = "hello"; s2 += " world"; s1 = s2 + " !!!"; // Using StringBuilder class for performance var s3:StringBuilder = new StringBuilder(); s3.Append("hello"); s3.Append(" world"); s3.Append(" !!!"); 17.事件处理程序委托 void MyButton_Click(Object sender, EventArgs E) { ... } Sub MyButton_Click(Sender As Object, E As EventArgs) ... End Sub function MyButton_Click(sender : Object, E : EventArgs) { ... } 18.声明事件 // Create a public event public event EventHandler MyEvent; // Create a method for firing the event protected void OnMyEvent(EventArgs e) { MyEvent(this, e); } ' Create a public event Public Event MyEvent(Sender as Object, E as EventArgs) ' Create a method for firing the event Protected Sub OnMyEvent(E As EventArgs) RaiseEvent MyEvent(Me, E) End Sub JScript does not support the creation of events. JScript can only consume events by declaring event handler delegates and adding those delegates to the events of another control.

19.向事件添加事件处理程序或从事件移除事件处理程序 Control.Change += new EventHandler(this.ChangeEventHandler); Control.Change -= new EventHandler(this.ChangeEventHandler); AddHandler Control.Change, AddressOf Me.ChangeEventHandler RemoveHandler Control.Change, AddressOf Me.ChangeEventHandler Control.Change += this.ChangeEventHandler; Control.Change -= this.ChangeEventHandler; 20.强制类型转换 MyObject obj = (MyObject)Session["Some Value"]; IMyObject iObj = obj; Dim obj As MyObject Dim iObj As IMyObject obj = Session("Some Value") iObj = CType(obj, IMyObject) var obj : MyObject = MyObject(Session("Some Value")); var iObj : IMyObject = obj; 21.转换 int i = 3; String s = i.ToString(); double d = Double.Parse(s); Dim i As Integer Dim s As String Dim d As Double i = 3 s = i.ToString() d = CDbl(s) ' See also CDbl(...), CStr(...), ... var i : int = 3; var s : String = i.ToString(); var d : double = Number(s); 22.带继承的类定义 using System; namespace MySpace { public class Foo : Bar { int x; public Foo() { x = 4; } public void Add(int x) { this.x += x; } override public int GetNum() { return x; } } } // csc /out:librarycs.dll /t:library // library.cs Imports System Namespace MySpace Public Class Foo : Inherits Bar Dim x As Integer Public Sub New() MyBase.New() x = 4 End Sub Public Sub Add(x As Integer) Me.x = Me.x + x End Sub Overrides Public Function GetNum() As Integer Return x End Function End Class End Namespace ' vbc /out:libraryvb.dll /t:library ' library.vb import System; package MySpace { class Foo extends Bar { private var x : int; function Foo() { x = 4; } function Add(x : int) { this.x += x; } override function GetNum() : int { return x; } } } // jsc /out:libraryjs.dll library.js 23.实现接口 public class MyClass : IEnumerable { ... IEnumerator IEnumerable.GetEnumerator() { ... } } Public Class MyClass : Implements IEnumerable ... Function IEnumerable_GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator ... End Function End Class public class MyClass implements IEnumerable { ... function IEnumerable.GetEnumerator() : IEnumerator { ... } } 24.带 Main 方法的类定义 using System; public class ConsoleCS { public ConsoleCS() { Console.WriteLine("Object Created"); } public static void Main (String[] args) { Console.WriteLine("Hello World"); ConsoleCS ccs = new ConsoleCS(); } } // csc /out:consolecs.exe /t:exe console.cs Imports System Public Class ConsoleVB Public Sub New() MyBase.New() Console.WriteLine("Object Created") End Sub Public Shared Sub Main() Console.WriteLine("Hello World") Dim cvb As New ConsoleVB End Sub End Class ' vbc /out:consolevb.exe /t:exe console.vb class ConsoleCS { function ConsoleCS() { print("Object Created"); } static function Main (args : String[]) { print("Hello World"); var ccs : ConsoleCS = new ConsoleCS(); } } // jsc /out:consolejs.exe /exe console.js

25.标准模块 using System; public class Module { public static void Main (String[] args) { Console.WriteLine("Hello World"); } } // csc /out:consolecs.exe /t:exe console.cs Imports System Public Module ConsoleVB Public Sub Main() Console.WriteLine("Hello World") End Sub End Module ' vbc /out:consolevb.exe /t:exe console.vb print("Hello World"); // jsc /out:consolejs.exe /exe console.js