• C# 与 VB.NET 对比


    Table of Contents

    1.0       Introduction

    1.1   Purpose & Scope

    2.0       Comparison

    2.1   Program Structure

    2.2   Comments

    2.3   Data Types

    2.4   Constants

    2.5   Enumerations

    2.6   Operators

    2.7   Choices

    2.8   Loops

    2.9   Arrays

    2.10Functions

    2.11Strings

    2.12Exception Handling

    2.13Namespaces

    2.14Classes / Interfaces

    2.15Constructors / Destructors

    2.16Using Objects

    2.17Structs

    2.18Properties

    2.19Delegates / Events

    2.20Console I/O

    2.21File I/O

    3.0       References


    1.0     Introduction

    1.1      Purpose & Scope

    This document is to compare the syntax between the VB.Net and C#.Net for various coding concepts.

    2.0     Comparison

    2.1      Program Structure

    VB.NET

    C#.NET

    Imports System

    Namespace Hello
       Class HelloWorld
          Overloads Shared Sub Main(ByVal args() As String)
             Dim name As String = "VB.NET"

             'See if an argument was passed from the command line
              If args.Length = 1 Then name = args(0)

              Console.WriteLine("Hello, " & name & "!")
          End Sub
       End Class
    End Namespace

    using System;

    namespace Hello {
       public class HelloWorld {
          public static void Main(string[] args) {
             string name = "C#";

             // See if an argument was passed from the command line
             if (args.Length == 1)
                name = args[0];

             Console.WriteLine("Hello, " + name + "!");
          }
       }
    }

     

    2.2      Comments

    VB.NET

    C#.NET

    ' Single line only
    REM Single line only
    ''' <summary>XML comments</summary>

    // Single line
    /* Multiple
        line  */
    /// <summary>XML comments on single line</summary>
    /** <summary>XML comments on multiple lines</summary> */

    2.3      Data Types

    VB.NET

    C#.NET

    Value Types
    Boolean
    Byte, SByte
    Char
    Short, UShort, Integer, UInteger, Long, ULong
    Single, Double
    Decimal
    Date

    Reference Types
    Object
    String

    Initializing
    Dim correct As Boolean = True
    Dim b As Byte = &H2A   'hex
    Dim o As Byte = &O52   'octal
    Dim person As Object = Nothing
    Dim name As String = "Dwight"
    Dim grade As Char = "B"c
    Dim today As Date = #12/31/2007 12:15:00 PM#
    Dim amount As Decimal = 35.99@
    Dim gpa As Single = 2.9!
    Dim pi As Double = 3.14159265
    Dim lTotal As Long = 123456L
    Dim sTotal As Short = 123S
    Dim usTotal As UShort = 123US
    Dim uiTotal As UInteger = 123UI
    Dim ulTotal As ULong = 123UL

    Type Information
    Dim x As Integer
    Console.WriteLine(x.
    GetType())          ' Prints System.Int32
    Console.WriteLine(GetType(Integer))   ' Prints System.Int32
    Console.WriteLine(
    TypeName(x))        ' Prints Integer

    Type Conversion
    Dim d As Single = 3.5
    Dim i As Integer =
    CType(d, Integer)   ' set to 4 (Banker's rounding)
    i =
    CInt(d)  ' same result as CType
    i =
    Int(d)    ' set to 3 (Int function truncates the decimal)

    Value Types
    bool
    byte, sbyte
    char
    short, ushort, int, uint, long, ulong
    float, double
    decimal
    DateTime   (not a built-in C# type)

    Reference Types
    object
    string

    Initializing
    bool correct = true;
    byte b = 0x2A;   // hex

    object person = null;
    string name = "Dwight";
    char grade = 'B';
    DateTime today = DateTime.Parse("12/31/2007 12:15:00");
    decimal amount = 35.99m;
    float gpa = 2.9f;
    double pi = 3.14159265;
    long lTotal = 123456L;
    short sTotal = 123;
    ushort usTotal = 123;
    uint uiTotal = 123;
    ulong ulTotal = 123;

    Type Information
    int x;
    Console.WriteLine(x.
    GetType());              // Prints System.Int32
    Console.WriteLine(
    typeof(int));               // Prints System.Int32
    Console.WriteLine(x.GetType().Name);   // prints Int32

    Type Conversion
    float d = 3.5f;
    int i =
    (int)d;   // set to 3  (truncates decimal)

    2.4      Constants

    VB.NET

    C#.NET

    Const MAX_STUDENTS As Integer = 25

    ' Can set to a const or var; may be initialized in a constructor
    ReadOnly MIN_DIAMETER As Single = 4.93

    const int MAX_STUDENTS = 25;

    // Can set to a const or var; may be initialized in a constructor
    readonly float MIN_DIAMETER = 4.93f;

    2.5      Enumerations

    VB.NET

    C#.NET

    Enum Action
      Start 
      [Stop]   ' Stop is a reserved word
      Rewind
      Forward
    End Enum

    Enum Status
      Flunk = 50
      Pass = 70
      Excel = 90
    End Enum
    Dim a As Action = Action.Stop
    If a <> Action.Start Then _
       Console.WriteLine(a.ToString & " is " & a)     ' Prints "Stop is 1"

    Console.WriteLine(Status.Pass)     ' Prints 70
    Console.WriteLine(Status.Pass.ToString())     ' Prints Pass

    enum Action {Start, Stop, Rewind, Forward};
    enum Status {Flunk = 50, Pass = 70, Excel = 90};

    Action a = Action.Stop;
    if (a != Action.Start)
      Console.WriteLine(a + " is " + (int) a);    // Prints "Stop is 1"

    Console.WriteLine((int) Status.Pass);    // Prints 70
    Console.WriteLine(Status.Pass);      // Prints Pass

    2.6      Operators

    VB.NET

    C#.NET

    Comparison
    =  <  >  <=  >=  <>

    Arithmetic
    +  -  *  /
    Mod
    "  (integer division)
    ^  (raise to a power)

    Assignment
    =  +=  -=  *=  /=  "=  ^=  <<=  >>=  &=

    Bitwise
    And   Or   Xor   Not   <<   >>

    Logical
    AndAlso   OrElse   And   Or   Xor   Not

    Note: AndAlso and OrElse perform short-circuit logical evaluations

    String Concatenation
    &

    Comparison
    ==  <  >  <=  >=  !=

    Arithmetic
    +  -  *  /
    %  (mod)
    /  (integer division if both operands are ints)
    Math.Pow(x, y)

    Assignment
    =  +=  -=  *=  /=   %=  &=  |=  ^=  <<=  >>=  ++  --

    Bitwise
    &   |   ^   ~   <<   >>

    Logical
    &&   ||   &   |   ^   !

    Note: && and || perform short-circuit logical evaluations

    String Concatenation
    +

    2.7      Choices

    VB.NET

    C#.NET

    greeting = IIf(age < 20, "What's up?", "Hello")

    ' One line doesn't require "End If"
    If age < 20 Then greeting = "What's up?"
    If age < 20 Then greeting = "What's up?" Else greeting = "Hello"

    ' Use : to put two commands on same line
    If x <> 100 And y < 5 Then x *= 5 : y *= 2  

    ' Preferred
    If x <> 100 And y < 5 Then
      x *= 5
      y *= 2
    End If

    ' To break up any long single line use _
    If whenYouHaveAReally < longLine And _
      itNeedsToBeBrokenInto2 > Lines 
    Then _
      UseTheUnderscore(charToBreakItUp)

    'If x > 5 Then
      x *= y
    ElseIf x = 5 Then
      x += y
    ElseIf x < 10 Then
      x -= y
    Else
      x /= y
    End If

    Select Case color   ' Must be a primitive data type
     
    Case "pink", "red"
        r += 1
     
    Case "blue"
        b += 1
     
    Case "green"
        g += 1
     
    Case Else
        other += 1
    End Select

    greeting = age < 20 ? "What's up?" : "Hello";

    if (age < 20)
      greeting = "What's up?";
    else
      greeting = "Hello";

    // Multiple statements must be enclosed in {}
    if (x != 100 && y < 5) {   
      x *= 5;
      y *= 2;
    }

    No need for _ or : since ; is used to terminate each statement.



    if (x > 5)
      x *= y;
    else if (x == 5)
      x += y;
    else if (x < 10)
      x -= y;
    else
      x /= y;


    // Every case must end with break or goto case
    switch (color) {                          // Must be integer or string
     
    case "pink":
     
    case "red":    r++;    break;
     
    case "blue":   b++;   break;
     case "green": g++;   break;
     default:    other++;   break;       // break necessary on default
    }

    2.8      Loops

    VB.NET

    C#.NET

    Pre-test Loops:

    While c < 10
      c += 1
    End While

    Do Until c = 10 
      c += 1
    Loop

    Do While c < 10
      c += 1
    Loop

    For c = 2 To 10 Step 2
      Console.WriteLine(c)
    Next

    Post-test Loops:

    Do 
      c += 1
    Loop While c < 10

    Do 
      c += 1
    Loop Until c = 10

    '  Array or collection looping
    Dim names As String() = {"Fred", "Sue", "Barney"}
    For Each s As String In names
      Console.WriteLine(s)
    Next

    ' Breaking out of loops
    Dim i As Integer = 0
    While (True)
      If (i = 5) Then Exit While
      i += 1
    End While

    ' Continue to next iteration
    For i = 0 To 4
      If i < 4 Then Continue For
      Console.WriteLine(i)   ' Only prints 4
    Next

    Pre-test Loops: 

    // no "until" keyword
    while (c < 10)
      c++;

    for (c = 2; c <= 10; c += 2)
      Console.WriteLine(c);



     Post-test Loop:

    do
      c++;
    while (c < 10);




    // Array or collection looping
    string[] names = {"Fred", "Sue", "Barney"};
    foreach (string s in names)
      Console.WriteLine(s);

    // Breaking out of loops
    int i = 0;
    while (true) {
      if (i == 5)
        break;
      i++;
    }

    // Continue to next iteration
    for (i = 0; i < 5; i++) {
      if (i < 4)
        continue;
      Console.WriteLine(i);   // Only prints 4
    }

    2.9      Arrays

    VB.NET

    C#.NET

    Dim nums() As Integer = {1, 2, 3} 
    For i As Integer = 0 To nums.Length - 1
      Console.WriteLine(nums(i))
    Next

    ' 4 is the index of the last element, so it holds 5 elements
    Dim names(4) As String
    names(0) = "David"
    names(5) = "Bobby"  ' Throws System.IndexOutOfRangeException

    ' Resize the array, keeping the existing values (Preserve is optional)
    ReDim Preserve names(6)



    Dim twoD(rows-1, cols-1) As Single
    twoD(2, 0) = 4.5

    Dim jagged
    ()() As Integer = { _
      New Integer(4) {}, New Integer(1) {}, New Integer(2) {} }
    jagged(0)(4) = 5

    int[] nums = {1, 2, 3};
    for (int i = 0; i < nums.Length; i++)
      Console.WriteLine(nums[i]);


    // 5 is the size of the array
    string[] names = new string[5];
    names[0] = "David";
    names[5] = "Bobby";   // Throws System.IndexOutOfRangeException


    // C# can't dynamically resize an array.  Just copy into new array.
    string[] names2 = new string[7];
    Array.Copy(names, names2, names.Length);   // or names.CopyTo(names2, 0); 

    float[,] twoD = new float[rows, cols];
    twoD[2,0] = 4.5f; 

    int[][] jagged = new int[3][] {
      new int[5], new int[2], new int[3] };
    jagged[0][4] = 5;

    2.10 Functions

    VB.NET

    C#.NET

    ' Pass by value (in, default), reference (in/out), and reference (out) 
    Sub TestFunc(ByVal x As Integer, ByRef y As Integer, ByRef z As Integer)
      x += 1
      y += 1
      z = 5
    End Sub

    Dim a = 1, b = 1, c As Integer   ' c set to zero by default 
    TestFunc(a, b, c)
    Console.WriteLine("{0} {1} {2}", a, b, c)   ' 1 2 5

    ' Accept variable number of arguments
    Function Sum(ByVal ParamArray nums As Integer()) As Integer
      Sum = 0 
      For Each i As Integer In nums
        Sum += i
      Next
    End Function   ' Or use Return statement like C#

    Dim total As Integer = Sum(4, 3, 2, 1)   ' returns 10

    ' Optional parameters must be listed last and must have a default value
    Sub SayHello(ByVal name As String,
    Optional ByVal prefix As String = "")
      Console.WriteLine("Greetings, " & prefix & " " & name)
    End Sub

    SayHello("Strangelove", "Dr.")
    SayHello("Madonna")

    // Pass by value (in, default), reference (in/out), and reference (out)
    void TestFunc(int x, ref int y, out int z) {
      x++;  
      y++;
      z = 5;
    }

    int a = 1, b = 1, c;  // c doesn't need initializing
    TestFunc(a,
    ref b, out c);
    Console.WriteLine("{0} {1} {2}", a, b, c);  // 1 2 5

    // Accept variable number of arguments
    int Sum(
    params int[] nums) {
      int sum = 0;
      foreach (int i in nums)
        sum += i;
      return sum;
    }

    int total = Sum(4, 3, 2, 1);   // returns 10

    /* C# doesn't support optional arguments/parameters.  Just create two different versions of the same function. */ 
    void SayHello(string name, string prefix) {
      Console.WriteLine("Greetings, " + prefix + " " + name);


    void SayHello(string name) {
      SayHello(name, "");
    }

    2.11 Strings

    VB.NET

    C#.NET

    Special character constants
    vbCrLf, vbCr, vbLf, vbNewLine
    vbNullString
    vbTab
    vbBack
    vbFormFeed
    vbVerticalTab
    ""

    ' String concatenation (use & or +)
    Dim school As String = "Harding"
    & vbTab
    school = school & "University" ' school is "Harding (tab) University"

    ' Chars
    Dim letter As
    Char = school.Chars(0)   ' letter is H
    letter = Convert.ToChar(65)                ' letter is A
    letter =
    Chr(65)                                 ' same thing
    Dim word() As Char = school.ToCharArray() ' word holds Harding

    ' No string literal operator 
    Dim msg As String = "File is c:"temp"x.dat" 


    ' String comparison
    Dim mascot As String = "Bisons"
    If (mascot = "Bisons") Then   ' true
    If (mascot.
    Equals("Bisons")) Then   ' true
    If (mascot.
    ToUpper().Equals("BISONS")) Then  ' true
    If (mascot.
    CompareTo("Bisons") = 0) Then   ' true

    Console.WriteLine(mascot.Substring(2, 3)) ' Prints "son"

    ' String matching
    If ("John 3:16" Like "Jo[Hh]? #:*") Then   'true

    Imports System.Text.RegularExpressions   ' More powerful than Like
    Dim r As New Regex("Jo[hH]. "d:*")
    If (r.Match("John 3:16").Success) Then   'true

    ' My birthday: Oct 12, 1973
    Dim dt As New DateTime(1973, 10, 12)
    Dim s As String = "My birthday: " & dt.ToString("MMM dd, yyyy")

    ' Mutable string
    Dim buffer As New System.Text.StringBuilder("two ")
    buffer.Append("three ")
    buffer.Insert(0, "one ")
    buffer.Replace("two", "TWO")
    Console.WriteLine(buffer)         ' Prints "one TWO three"

    Escape sequences
    "r    // carriage-return
    "n    // line-feed
    "t    // tab
    ""    // backslash
    ""    // quote


    // String concatenation
    string school = "Harding"t";
    school = school + "University";   // school is "Harding (tab) University"

    // Chars
    char letter = school[0];            // letter is H
    letter = Convert.ToChar(65);     // letter is A
    letter =
    (char)65;                    // same thing
    char[] word = school.ToCharArray();   // word holds Harding

    // String literal
    string msg = @"File is c:"temp"x.dat";
    // same as
    string msg = "File is c:""temp""x.dat";

    // String comparison
    string mascot = "Bisons";
    if (mascot == "Bisons")    // true
    if (mascot.
    Equals("Bisons"))   // true
    if (mascot.
    ToUpper().Equals("BISONS"))   // true
    if (mascot.
    CompareTo("Bisons") == 0)    // true

    Console.WriteLine(mascot.Substring(2, 3));    // Prints "son"

    // String matching
    // No Like equivalent - use regular expressions


    using System.Text.RegularExpressions;
    Regex r = new Regex(@"Jo[hH]. "d:*");
    if (r.Match("John 3:16").Success)   // true

    // My birthday: Oct 12, 1973
    DateTime dt = new DateTime(1973, 10, 12);
    string s = "My birthday: " + dt.ToString("MMM dd, yyyy");

    // Mutable string
    System.Text.
    StringBuilder buffer = new System.Text.StringBuilder("two ");
    buffer.
    Append("three ");
    buffer.
    Insert(0, "one ");
    buffer.
    Replace("two", "TWO");
    Console.WriteLine(buffer);     // Prints "one TWO three"

    2.12 Exception Handling

    VB.NET

    C#.NET

    ' Throw an exception
    Dim ex As New Exception("Something is really wrong.")
    Throw  ex 

    ' Catch an exception
    Try 
      y = 0
      x = 10 / y
    Catch ex As Exception When y = 0 ' Argument and When is optional
      Console.WriteLine(ex.Message)
    Finally
      Beep()
    End Try

    ' Deprecated unstructured error handling
    On Error GoTo MyErrorHandler
    ...
    MyErrorHandler: Console.WriteLine(Err.Description)

    // Throw an exception
    Exception up = new Exception("Something is really wrong.");
    throw up;  // ha ha

    // Catch an exception
    try
      y = 0;
      x = 10 / y;
    }
    catch (Exception ex) {   // Argument is optional, no "When" keyword 
      Console.WriteLine(ex.Message);
    }
    finally {
      // Requires reference to the Microsoft.VisualBasic.dll
      // assembly (pre .NET Framework v2.0)

      Microsoft.VisualBasic.Interaction.Beep();
    }

    2.13 Namespaces

    VB.NET

    C#.NET

    Namespace Harding.Compsci.Graphics 
      ...
    End Namespace

    ' or

    Namespace Harding
     
    Namespace Compsci
       
    Namespace Graphics 
          ...
       
    End Namespace
     
    End Namespace
    End Namespace

    Imports Harding.Compsci.Graphics

    namespace Harding.Compsci.Graphics {
      ...
    }

    // or

    namespace Harding {
     
    namespace Compsci {
       
    namespace Graphics {
          ...
        }
      }
    }

    using Harding.Compsci.Graphics;

    2.14 Classes / Interfaces

    VB.NET

    C#.NET

    Accessibility keywords
    Public
    Private
    Friend                   
    Protected
    Protected Friend
    Shared

    ' Inheritance
    Class FootballGame
     
    Inherits Competition
      ...
    End Class 

    ' Interface definition
    Interface IAlarmClock 
      ...
    End Interface

    // Extending an interface 
    Interface IAlarmClock
     
    Inherits IClock
      ...
    End Interface

    // Interface implementation
    Class WristWatch 
     
    Implements IAlarmClock, ITimer 
       ...
    End Class 

    Accessibility keywords
    public
    private
    internal
    protected
    protected internal
    static

    // Inheritance
    class FootballGame : Competition {
      ...
    }


    // Interface definition

    interface IAlarmClock {
      ...
    }

    // Extending an interface 
    interface IAlarmClock : IClock {
      ...
    }


    // Interface implementation

    class WristWatch : IAlarmClock, ITimer {
       ...
    }

    2.15 Constructors / Destructors

    VB.NET

    C#.NET

    Class SuperHero
      Private _powerLevel As Integer

      Public Sub New()
        _powerLevel = 0
      End Sub

      Public Sub New(ByVal powerLevel As Integer)
        Me._powerLevel = powerLevel
      End Sub

      Protected Overrides Sub Finalize() 
       ' Desctructor code to free unmanaged resources
        MyBase.Finalize()
      End Sub
    End Class

    class SuperHero {
      private int _powerLevel;

      public SuperHero() {
         _powerLevel = 0;
      }

      public SuperHero(int powerLevel) {
        this._powerLevel= powerLevel; 
      }

     
    ~SuperHero() {
        // Destructor code to free unmanaged resources.
        // Implicitly creates a Finalize method

      }
    }

    2.16 Using Objects

    VB.NET

    C#.NET

    Dim hero As SuperHero = New SuperHero
    ' or
    Dim hero As New SuperHero

    With hero
      .Name = "SpamMan"
      .PowerLevel = 3
    End With

    hero.Defend("Laura Jones")
    hero.Rest()     ' Calling Shared method
    ' or
    SuperHero.Rest()

    Dim hero2 As SuperHero = hero  ' Both reference the same object
    hero2.Name = "WormWoman"
    Console.WriteLine(hero.Name)   ' Prints WormWoman

    hero = Nothing    ' Free the object

    If hero IsNothing Then _
      hero = New SuperHero

    Dim obj As Object = New SuperHero
    If
    TypeOf obj Is SuperHero Then _
      Console.WriteLine("Is a SuperHero object.")

    ' Mark object for quick disposal
    Using reader As StreamReader = File.OpenText("test.txt")
      Dim line As String = reader.ReadLine()
      While Not line Is Nothing
        Console.WriteLine(line)
        line = reader.ReadLine()
      End While
    End Using

    SuperHero hero = new SuperHero();


    // No "With" construct
    hero.Name = "SpamMan";
    hero.PowerLevel = 3;

    hero.Defend("Laura Jones");
    SuperHero.Rest();   // Calling static method



    SuperHero hero2 = hero;   // Both reference the same object
    hero2.Name = "WormWoman";
    Console.WriteLine(hero.Name);   // Prints WormWoman

    hero = null ;   // Free the object

    if (hero == null)
      hero = new SuperHero();

    Object obj = new SuperHero(); 
    if (obj
    is SuperHero)
      Console.WriteLine("Is a SuperHero object.");

    // Mark object for quick disposal
    using (StreamReader reader = File.OpenText("test.txt")) {
      string line;
      while ((line = reader.ReadLine()) != null)
        Console.WriteLine(line);
    }

    2.17 Structs

    VB.NET

    C#.NET

    Structure StudentRecord
      Public name As String
      Public gpa As Single

      Public Sub New(ByVal name As String, ByVal gpa As Single)
        Me.name = name
        Me.gpa = gpa
      End Sub
    End Structure

    Dim stu As StudentRecord = New StudentRecord("Bob", 3.5)
    Dim stu2 As StudentRecord = stu  

    stu2.name = "Sue"
    Console.WriteLine(stu.name)    ' Prints Bob
    Console.WriteLine(stu2.name)  ' Prints Sue

    struct StudentRecord {
      public string name;
      public float gpa;

      public StudentRecord(string name, float gpa) {
        this.name = name;
        this.gpa = gpa;
      }
    }

    StudentRecord stu = new StudentRecord("Bob", 3.5f);
    StudentRecord stu2 = stu;  

    stu2.name = "Sue";
    Console.WriteLine(stu.name);    // Prints Bob
    Console.WriteLine(stu2.name);   // Prints Sue

    2.18 Properties

    VB.NET

    C#.NET

    Private _size As Integer

    Public
    Property Size() As Integer
     
    Get
        Return _size
     
    End Get
     
    Set (ByVal Value As Integer)
        If Value < 0 Then
          _size = 0
        Else
          _size = Value
        End If
     
    End Set
    End Property

    foo.Size += 1

    private int _size;

    public int Size {
      get {
        return _size;
      }
      set {
        if (value < 0)
          _size = 0;
        else
          _size = value;
      }
    }


    foo.Size++;

    2.19 Delegates / Events

    VB.NET

    C#.NET

    Delegate Sub MsgArrivedEventHandler(ByVal message As String)

    Event MsgArrivedEvent As MsgArrivedEventHandler

    ' or to define an event which declares a delegate implicitly
    Event MsgArrivedEvent(ByVal message As String)

    AddHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback
    ' Won't throw an exception if obj is Nothing
    RaiseEvent MsgArrivedEvent("Test message")
    RemoveHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback

    Imports System.Windows.Forms

    Dim WithEvents MyButton As Button   ' WithEvents can't be used on local variable
    MyButton = New Button

    Private Sub MyButton_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs)
    Handles MyButton.Click
      MessageBox.Show(Me, "Button was clicked", "Info", _
        MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub

    delegate void MsgArrivedEventHandler(string message);

    event MsgArrivedEventHandler MsgArrivedEvent;

    // Delegates must be used with events in C#


    MsgArrivedEvent
    += new MsgArrivedEventHandler(My_MsgArrivedEventCallback);
    MsgArrivedEvent("Test message");    // Throws exception if obj is null
    MsgArrivedEvent
    -= new MsgArrivedEventHandler(My_MsgArrivedEventCallback);



    using System.Windows.Forms;

    Button MyButton = new Button(); 
    MyButton.Click += new System.EventHandler(MyButton_Click);

    private void MyButton_Click(object sender, System.EventArgs e) {
      MessageBox.Show(this, "Button was clicked", "Info",
        MessageBoxButtons.OK, MessageBoxIcon.Information);
    }

    2.20 Console I/O

    VB.NET

    C#.NET

    Console.Write("What's your name? ")
    Dim name As String = Console.ReadLine()
    Console.Write("How old are you? ")
    Dim age As Integer = Val(Console.ReadLine())
    Console.WriteLine("{0} is {1} years old.", name, age) 
    ' or
    Console.WriteLine(name & " is " & age & " years old.")

    Dim c As Integer
    c = Console.Read()    ' Read single char
    Console.WriteLine(c)   ' Prints 65 if user enters "A"

    Console.Write("What's your name? ");
    string name = Console.ReadLine();
    Console.Write("How old are you? ");
    int age = Convert.ToInt32(Console.ReadLine());
    Console.WriteLine("{0} is {1} years old.", name, age);
    // or
    Console.WriteLine(name + " is " + age + " years old.");


    int c = Console.Read();  // Read single char
    Console.WriteLine(c);    // Prints 65 if user enters "A"

    2.21 File I/O

    VB.NET

    C#.NET

    Imports System.IO

    ' Write out to text file
    Dim writer As
    StreamWriter = File.CreateText("c:"myfile.txt")
    writer.WriteLine("Out to file.")
    writer.Close()

    ' Read all lines from text file
    Dim reader As
    StreamReader = File.OpenText("c:"myfile.txt")
    Dim line As String = reader.ReadLine()
    While Not line Is Nothing
      Console.WriteLine(line)
      line = reader.ReadLine()
    End While
    reader.Close()

    ' Write out to binary file
    Dim str As String = "Text data"
    Dim num As Integer = 123
    Dim binWriter As New
    BinaryWriter(File.OpenWrite("c:"myfile.dat")) 
    binWriter.Write(str) 
    binWriter.Write(num) 
    binWriter.Close()

    ' Read from binary file
    Dim binReader As New
    BinaryReader(File.OpenRead("c:"myfile.dat"))
    str = binReader.ReadString()
    num = binReader.ReadInt32()
    binReader.Close()

    using System.IO;

    // Write out to text file
    StreamWriter writer = File.CreateText("c:""myfile.txt");
    writer.WriteLine("Out to file.");
    writer.Close();

    // Read all lines from text file
    StreamReader reader = File.OpenText("c:""myfile.txt");
    string line = reader.ReadLine();
    while (line != null) {
      Console.WriteLine(line);
      line = reader.ReadLine();
    }
    reader.Close();

    // Write out to binary file
    string str = "Text data";
    int num = 123;
    BinaryWriter binWriter = new BinaryWriter(File.OpenWrite("c:""myfile.dat"));
    binWriter.Write(str);
    binWriter.Write(num);
    binWriter.Close();

    // Read from binary file
    BinaryReader binReader = new BinaryReader(File.OpenRead("c:""myfile.dat"));
    str = binReader.ReadString();
    num = binReader.ReadInt32();
    binReader.Close();

    3.0    References

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  • 原文地址:https://www.cnblogs.com/anderslly/p/csharp_vbnet_comparision.html
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