C#和VB语法对照表

C#和VB语法对照 ---摘自《ChinaAsp网络》(文/讨饭猫) ASP+内置支持3种语言:C#，Visual Basic(注意不是VBScript)，JScript。下面列出一个 简单的C#和VB语法，看看你到底喜欢那个, C# 语法 VB 语法 定义变量 int x; Dim x As Integer String s; Dim s As String String s1, s2; Dim s1, s2 As String Object o; Dim o 'Implicitly Object Object obj = new Object(); Dim obj As New Object() public String name; Public name As String 输出内容 Response.Write("foo"); Response.Write("foo") 注释 ' This is a comment ' This // This is a comment ' is /* This is a multi-line comment */ ' a ' multi-line ' comment 读取数据集合数组 Dim s, value As String s = Request.QueryString("Name") String s=Request.QueryString["Name"]; value = Request.Cookies("Key").Value String value=Request.Cookies["key"]; 'Note that default non-indexed properties 'must be explicitly named in VB 定义简单数据集 public String name { get { ... return ...; } set { ... = value; } } Public Property Name As String Get ... Return ...; End Get Set ... = Value; End Set End Property 数组 String[] a = new String[3]; a[0] = "1"; a[1] = "2"; a[2] = "3 String[][] a = new String[3][3]; a[0][0] = "1"; a[1][0] = "2"; a[2][0] = "3"; Dim a(3) As String a(0) = "1" a(1) = "2" a(2) = "3" Dim a(3,3) As String a(0,0) = "1" a(1,0) = "2" a(2,0) = "3" ' Array of unspecified bounds (NA in C#) Dim a() As String a(0,0) = "1" a(1,0) = "2" a(2,0) = "3" Dim a(,) As String a(0,0) = "1" a(1,0) = "2" a(2,0) = "3" 初始化变量 String s = "Hello World"; int i = 1 double[] a = { 3.00, 4.00, 5.00 }; Dim s As String = "Hello World" Dim i As Integer = 1 Dim a() As Double = { 3.00, 4.00, 5.00 } If 结构 if (Request.QueryString != null) { ... } If Not (Request.QueryString = Null) ... End If Case 结构 switch (FirstName){ case "John" : ... break; case "Paul" : ... break; case "Ringo" : ... break; } Select (FirstName) case "John" : ... case "Paul" : ... case "Ringo" : ... End Select 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 While 循环 int i = 0; while (i<3) { Console.WriteLine(i.ToString()); i += 1; } Dim I As Integer I = 0 Do While I 字符串操作 String s1; String s2 = "hello"; s2 += " world"; s1 = s2 + " !!!"; Dim s1, s2 As String s2 = "hello" s2 &= " world" s1 = s2 & " !!!" 事件处理 void MyButton_Click(Object sender, EventArgs E) { ... } Sub MyButton_Click(Sender As Object, E As EventArgs) ... End Sub 注意 ByVal 在VB中是省缺参数 对象操作 MyObject obj = (MyObject)Session["Some Value"]; IMyObject iObj = obj Dim bj As MyObject Dim iObj As IMyObject obj = Session("Some Value") iObj = CType(obj, IMyObject) 类型转换 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) ' 参见 CDbl(...), CStr(...), ... 类定义和继承 using System; namespace MySpace { public class Foo : Bar { int x; public Foo() {x = 4; } public void Add(int x) { this.x += x; } 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 Public Function GetNum() As Integer Return x End Function End Class End Namespace ' vbc /out:libraryvb.dll /t:library library.vb (也许是多年来用惯了C的缘故，一直喜欢C那种简练，个性化的风格，文字和符号混合使 用，可以让眼睛迅速找到关键所在，避免视线被淹没在复杂的字符串中，所以即使在 ASP 时 代，也是坚持使用风格类似的 JScript，现在终于……hehehe…..-讨饭猫)