1 变量声明
int x;
String s;
String s1, s2;
Object o;
Object obj = new Object();
public String name;
Dim x As Integer
Dim s As String
Dim s1, s2 As String
Dim o 'Implicitly Object
Dim obj As New Object()
Public name As String
2 语句
Response.Write("foo");
Response.Write("foo")
3 注释
// This is a comment
/*
This
is
a
multiline
comment
*/
' This is a comment
' This
' is
' a
' multiline
' comment
4 访问索引属性
String s = Request.QueryString["Name"];
String value = Request.Cookies["key"];
Dim s, value As String
s = Request.QueryString("Name")
value = Request.Cookies("Key").Value
'Note that default non-indexed properties
'must be explicitly named in VB
5 声明索引属性
// Default Indexed Property
public String this[String name] {
get {
return (String) lookuptable[name];
}
}
' Default Indexed Property
Public Default ReadOnly Property DefaultProperty(Name As String) As String
Get
Return CStr(lookuptable(name))
End Get
End Property
6 声明简单属性
public String name {
get {
...
return ...;
}
set {
... = value;
}
}
Public Property Name As String
Get
...
Return ...
End Get
Set
... = Value
End Set
End Property
7 声明和使用枚举
// Declare the Enumeration
public enum MessageSize {
Small = 0,
Medium = 1,
Large = 2
}
// Create a Field or Property
public MessageSize msgsize;
// Assign to the property using the Enumeration values
msgsize = Small;
' 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
8 枚举集合
foreach ( String s in coll ) {
...
}
Dim S As String
For Each S In Coll
...
Next
9 声明和使用方法
// Declare a void return function
void voidfunction() {
...
}
// Declare a function that returns a value
String stringfunction() {
...
return (String) val;
}
// Declare a function that takes and returns values
String parmfunction(String a, String b) {
...
return (String) (a + b);
}
// Use the Functions
voidfunction();
String s1 = stringfunction();
String s2 = parmfunction("Hello", "World!");
' 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!")
10 自定义属性
// Stand-alone attribute
[STAThread]
// Attribute with parameters
[DllImport("ADVAPI32.DLL")]
// Attribute with named parameters
[DllImport("KERNEL32.DLL", CharSet=CharSet.Auto)]
' Stand-alone attribute
<STAThread>
' Attribute with parameters
<DllImport("ADVAPI32.DLL")>
' Attribute with named parameters
<DllImport("KERNEL32.DLL", CharSet:=CharSet.Auto)>
11 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(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"
12 初始化
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 }
13 If 语句
if (Request.QueryString != null) {
...
}
If Not (Request.QueryString = Nothing)
...
End If
14 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
15 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
16 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
17 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
18 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(" !!!")
19 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
20 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
21 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
22 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)
23 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(...), ...
24 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
25 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
26 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
27 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
28 .....省略~~
请不要把帖子发到VB区~谢谢~
[此贴子已经被作者于2006-10-19 8:53:18编辑过]
