1. <wbr id="m8vu6"></wbr>

      <del id="m8vu6"><center id="m8vu6"><source id="m8vu6"></source></center></del>
        <p id="m8vu6"><sub id="m8vu6"></sub></p>

        VB.net 2010 視頻教程 VB.net 2010 視頻教程 VB.net 2010 視頻教程
        SQL Server 2008 視頻教程 c#入門經典教程 Visual Basic從門到精通視頻教程
        當前位置:
        首頁 > 編程開發 > VBnet >
        • vb.net教程之VB.net & C# comparison cheat sheet

        • 2019-06-19 22:04 來源:未知
        cheat sheet

        Comments

        VB.NET

         

        'Single line only
        Rem Single line only

         

        C#

        // Single line
        /* Multiple
        line */
        /// XML comments on single line
        /** XML comments on multiple lines */

        Program Structure

        VB.NET

         

        Imports System
        Namespace MyNameSpace
          Class HelloWorld
            'Entry point which delegates to C-style main Private Function
            Public Overloads Shared Sub Main()
              Main(System.Environment.GetCommandLineArgs())
            End Sub
        
          Overloads Shared Sub Main(args() As String)
            System.Console.WriteLine("Hello World")
          End Sub 'Main
          End Class 'HelloWorld End Namespace 'MyNameSpace

         

        C#

        using System
        Namespace MyNameSpace
        {
          class HelloWorld
          {     
            static void Main(string[] args)
            {
              System.Console.WriteLine("Hello World");
            }
          }
        }

        Data Types

        VB.NET

         

        'Value Types
        Boolean
        Byte
        Char (example: "A")
        Short, Integer, Long
        Single, Double
        Decimal
        Date 
        
        
        'Reference Types
        Object
        String
        
        
        
        Dim x As Integer
        System.Console.WriteLine(x.GetType())
        System.Console.WriteLine(TypeName(x)) 
        
        
        'Type conversion
        Dim d As Single = 3.5
        Dim i As Integer = CType (d, Integer)
        i = CInt (d)
        i = Int(d)

         

        C#

         

        //Value Types
        bool
        byte, sbyte
        char (example: 'A')
        short, ushort, int, uint, long, ulong
        float, double
        decimal
        DateTime 
        
        
        //Reference Types
        object
        string
        
        
        
        int x;
        Console.WriteLine(x.GetType())
        Console.WriteLine(typeof(int)) 
        
        
        //Type conversion
        float d = 3.5;
        int i = (int) d

         

        Constants

        VB.NET

        Const MAX_AUTHORS As Integer = 25
        ReadOnly MIN_RANK As Single = 5.00

        C#

        const int MAX_AUTHORS = 25;
        readonly float MIN_RANKING = 5.00;

        Enumerations

        VB.NET

         

        Enum Action
          Start
          'Stop is a reserved word
        [Stop]
          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 _
        'Prints "Stop is 1" 
           System.Console.WriteLine(a.ToString & " is " & a)
        
        'Prints 70
        System.Console.WriteLine(Status.Pass)
        'Prints Pass
        System.Console.WriteLine(Status.Pass.ToString())
        
        
        Enum Weekdays
           Saturday
           Sunday
           Monday
           Tuesday
           Wednesday
           Thursday
           Friday
        End Enum 'Weekdays

         

        C#

         

        enum Action {Start, Stop, Rewind, Forward};
        enum Status {Flunk = 50, Pass = 70, Excel = 90};
        
        
        
        
        
        
        
        
        
        
        
        Action a = Action.Stop;
        if (a != Action.Start)
        //Prints "Stop is 1"
          System.Console.WriteLine(a + " is " + (int) a); 
        
        // Prints 70
        System.Console.WriteLine((int) Status.Pass); 
        // Prints Pass
        System.Console.WriteLine(Status.Pass);
        
        
        
        enum Weekdays
        {
          Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, Friday
        }

         

        Operators

        VB.NET

         

        'Comparison
        =  <  >  <=  >=  <> 
        
        
        'Arithmetic
        +  -  *  /
        Mod
        \  (integer division)
        ^  (raise to a power) 
        
        
        'Assignment
        =  +=  -=  *=  /=  \=  ^=  <<=  >>=  &= 
        
        
        'Bitwise
        And  AndAlso  Or  OrElse  Not  <<  >> 
        
        
        'Logical
        And  AndAlso  Or  OrElse  Not 
        
        
        'String Concatenation
        & 

         

        C#

         

        //Comparison
        ==  <  >  <=  >=  != 
        
        
        //Arithmetic
        +  -  *  /
        %  (mod)
        /  (integer division if both operands are ints)
        Math.Pow(x, y) 
        
        
        //Assignment
        =  +=  -=  *=  /=   %=  &=  |=  ^=  <<=  >>=  ++  -- 
        
        
        //Bitwise
        &  |  ^   ~  <<  >> 
        
        
        //Logical
        &&  ||   ! 
        
        
        //String Concatenation
        +

         

        Choices

        VB.NET

         

        greeting = IIf(age < 20, "What's up?", "Hello") 
        
        
        'One line doesn't require "End If", no "Else"
        If language = "VB.NET" Then langType = "verbose" 
        
        
        '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 
        
        
        
        
        'or to break up any long single command use _
        If henYouHaveAReally < 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 
        
        
        'Must be a primitive data type
        Select Case color   
          Case "black", "red"
            r += 1
          Case "blue"
            b += 1
          Case "green"
            g += 1
          Case Else
            other += 1
        End Select

         

        C#

         

        greeting = age < 20 ? "What's up?" : "Hello"; 
        
        
        
        
        
        
        
        
        
        
        
        if (x != 100 && y < 5)
        {
          // Multiple statements must be enclosed in {}
          x *= 5;
          y *= 2;
        } 
        
        
        
        
        
        
        
        
        if (x > 5) 
          x *= y; 
        else if (x == 5) 
          x += y; 
        else if (x < 10) 
          x -= y; 
        else 
          x /= y;
        
        
        
        //Must be integer or string
        switch (color)
        {
          case "black":
          case "red":    r++;
           break;
          case "blue"
           break;
          case "green": g++;  
           break;
          default:    other++;
           break;
        }

         

        Loops

        VB.NET

         

        'Pre-test Loops:
        While c < 10
          c += 1
        End While Do Until c = 10
          c += 1
        Loop 
        
        
        'Post-test Loop:
        Do While c < 10
          c += 1
        Loop 
        
        
        For c = 2 To 10 Step 2
          System.Console.WriteLine(c)
        Next 
        
        
        
        'Array or collection looping
        Dim names As String() = {"Steven", "SuOk", "Sarah"}
        For Each s As String In names
          System.Console.WriteLine(s)
        Next

         

        C#

        //Pre-test Loops: while (i < 10)
          i++;
        for (i = 2; i < = 10; i += 2)
          System.Console.WriteLine(i); 
        
        
        
        
        
        
        //Post-test Loop:
        do
          i++;
        while (i < 10);
        
        
        
        
        
        
        
        
        // Array or collection looping
        string[] names = {"Steven", "SuOk", "Sarah"};
        foreach (string s in names)
          System.Console.WriteLine(s);

         

        Arrays

        VB.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) = "Steven"
        'Throws System.IndexOutOfRangeException
        names(5) = "Sarah"
        
        
        '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

         

        C#

         

        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] = "Steven";
        // Throws System.IndexOutOfRangeException
        names[5] = "Sarah"
        
        
        // C# can't dynamically resize an array.
        //Just copy into new array.
        string[] names2 = new string[7];
        // or names.CopyTo(names2, 0);
        Array.Copy(names, names2, names.Length); 
        
        
        
        float[,] twoD = new float[rows, cols];
        twoD[2,0] = 4.5; 
        
        
        int[][] jagged = new int[3][] {
          new int[5], new int[2], new int[3] };
        jagged[0][4] = 5;

         

        Functions

        VB.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 
        
        
        'c set to zero by default
        
        Dim a = 1, b = 1, c As Integer
        TestFunc(a, b, c)
        System.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 a 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 = "")
          System.Console.WriteLine("Greetings, " & prefix
        & " " & name)
        End Sub
        
        
        SayHello("Steven", "Dr.")
        SayHello("SuOk")

         

        C#

        // 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);
        System.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) {
          System.Console.WriteLine("Greetings, " + prefix + " " + name);
        }
        
        void SayHello(string name) {
          SayHello(name, "");
        }

         

        Exception Handling

        VB.NET

         

        Class Withfinally
           Public Shared Sub Main()
              Try
                 Dim x As Integer = 5
                 Dim y As Integer = 0
                 Dim z As Integer = x / y
                 Console.WriteLine(z)
              Catch e As DivideByZeroException
                 System.Console.WriteLine("Error occurred")
              Finally
                 System.Console.WriteLine("Thank you")
              End Try
           End Sub 'Main
        End Class 'Withfinally

         

        C#

         

        class  Withfinally
        {
          public static void Main()
          {
            try
            {
              int x = 5;
              int y = 0;
              int z = x/y;
              Console.WriteLine(z);
            }
            catch(DivideByZeroException e)
            {
              System.Console.WriteLine("Error occurred");
            }
            finally
            {
              System.Console.WriteLine("Thank you");
            }
          }
        }

         

        Namespaces

        VB.NET

         

        Namespace ASPAlliance.DotNet.Community
          ...
        End Namespace 
        
        
        'or 
        
        
        Namespace ASPAlliance 
          Namespace DotNet
            Namespace Community
              ...
            End Namespace
          End Namespace
        End Namespace 
        
        
        Imports ASPAlliance.DotNet.Community

         

        C#

         

        namespace ASPAlliance.DotNet.Community {
          ...
        } 
        
        
        // or 
        
        
        namespace ASPAlliance {
          namespace DotNet {
            namespace Community {
              ...
            }
          }
        } 
        
        
        using ASPAlliance.DotNet.Community;

         

        Classes / Interfaces

        VB.NET

         

        'Accessibility keywords
        Public
        Private
        Friend
        Protected
        Protected Friend
        Shared 
        
        
        'Inheritance
        Class Articles
          Inherits Authors
          ...
        End Class 
        
        
        Imports System
        
        
        Interface IArticle
           Sub Show()
        End Interface 'IArticle
         _
        
        
        Class IAuthor
           Implements IArticle
           
           Public Sub Show()
              System.Console.WriteLine("Show() method Implemented")
           End Sub 'Show
           
           'Entry point which delegates to C-style main Private Function
           Public Overloads Shared Sub Main()
              Main(System.Environment.GetCommandLineArgs())
           End Sub
           
           
           Overloads Public Shared Sub Main(args() As String)
              Dim author As New IAuthor()
              author.Show()
           End Sub 'Main
        End Class 'IAuthor

         

        C#

         

        //Accessibility keywords
        public
        private
        internal
        protected
        protected internal
        static 
        
        
        //Inheritance
        class Articles: Authors {
          ...
        } 
        
        
        using System;
        
        
        interface IArticle
        {
          void Show();
        }
        
        
        class IAuthor:IArticle
        {
          public void Show()
          {
            System.Console.WriteLine("Show() method Implemented");
          }
        
        
          public static void Main(string[] args)
          {
            IAuthor author = new IAuthor();
            author.Show();
          }
        }

         

        Constructors / Destructors

        VB.NET

        Class TopAuthor
          Private _topAuthor As Integer
        
          Public Sub New()
            _topAuthor = 0
          End Sub
        
          Public Sub New(ByVal topAuthor As Integer)
            Me._topAuthor = topAuthor
          End Sub
        
          Protected Overrides Sub Finalize()
           'Desctructor code to free unmanaged resources
            MyBase.Finalize() 
          End Sub
        End Class

        C#

         

        class TopAuthor {
          private int _topAuthor;
        
          public TopAuthor() {
             _topAuthor = 0;
          }
        
          public TopAuthor(int topAuthor) {
            this._topAuthor= topAuthor
          }
        
          ~TopAuthor() {
            // Destructor code to free unmanaged resources.
            // Implicitly creates a Finalize method
          }
        }

         

        Objects

        VB.NET

         

        Dim author As TopAuthor = New TopAuthor
        With author
          .Name = "Steven"
          .AuthorRanking = 3
        End With
        
        author.Rank("Scott")
        author.Demote() 'Calling Shared method
        'or
        TopAuthor.Rank() 
        
        
        Dim author2 As TopAuthor = author 'Both refer to same object
        author2.Name = "Joe"
        System.Console.WriteLine(author2.Name) 'Prints Joe 
        
        
        author = Nothing 'Free the object 
        
        
        If author Is Nothing Then _
          author = New TopAuthor 
        
        
        Dim obj As Object = New TopAuthor
        If TypeOf obj Is TopAuthor Then _
          System.Console.WriteLine("Is a TopAuthor object.")

         

        C#

         

        TopAuthor author = new TopAuthor();
        
        //No "With" construct
        author.Name = "Steven";
        author.AuthorRanking = 3; 
        
        
        author.Rank("Scott");
        TopAuthor.Demote() //Calling static method 
        
        
        
        
        TopAuthor author2 = author //Both refer to same object
        author2.Name = "Joe";
        System.Console.WriteLine(author2.Name) //Prints Joe 
        
        
        author = null //Free the object 
        
        
        if (author == null)
          author = new TopAuthor(); 
        
        
        Object obj = new TopAuthor(); 
        if (obj is TopAuthor)
          SystConsole.WriteLine("Is a TopAuthor object.");

         

        Structs

        VB.NET

         

        Structure AuthorRecord
          Public name As String
          Public rank As Single
        
          Public Sub New(ByVal name As String, ByVal rank As Single) 
            Me.name = name
            Me.rank = rank
          End Sub
        End Structure 
        
        
        Dim author As AuthorRecord = New AuthorRecord("Steven", 8.8)
        Dim author2 As AuthorRecord = author
        
        author2.name = "Scott"
        System.Console.WriteLine(author.name) 'Prints Steven
        System.Console.WriteLine(author2.name) 'Prints Scott

         

        C#

        struct AuthorRecord {
          public string name;
          public float rank;
        
          public AuthorRecord(string name, float rank) {
            this.name = name;
            this.rank = rank;
          }
        }
        
        
        
        AuthorRecord author = new AuthorRecord("Steven", 8.8);
        AuthorRecord author2 = author
        
        author.name = "Scott";
        SystemConsole.WriteLine(author.name); //Prints Steven
        System.Console.WriteLine(author2.name); //Prints Scott

         

        Properties

        VB.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
        
        
        Imports System
        
        
        Class [Date]
           
           Public Property Day() As Integer
              Get
                 Return day
              End Get
              Set
                 day = value
              End Set
           End Property
           Private day As Integer
           
           
           Public Property Month() As Integer
              Get
                 Return month
              End Get
              Set
                 month = value
              End Set
           End Property
           Private month As Integer
           
           
           Public Property Year() As Integer
              Get
                 Return year
              End Get
              Set
                 year = value
              End Set
           End Property
           Private year As Integer
           
           
           Public Function IsLeapYear(year As Integer) As Boolean
              Return(If year Mod 4 = 0 Then True Else False)
           End Function 'IsLeapYear
           
           Public Sub SetDate(day As Integer, month As Integer,
        year As Integer)
              Me.day = day
              Me.month = month
              Me.year = year
           End Sub 'SetDate
        End Class '[Date]

         

        C#

        private int _size;
        
        public int Size {
          get {
            return _size;
          }
          set {
            if (value < 0)
              _size = 0;
            else
              _size = value;
          }
        } 
        
        
        
        foo.Size++;
        
        
        using System;
        class Date
        {
            public int Day{
                get {
                    return day;
                }
                set {
                    day = value;
                }
            }
            int day;
        
        
            public int Month{
                get {
                    return month;
                }
                set {
                    month = value;
                }
            }
            int month;
        
        
            public int Year{
                get {
                    return year;
                }
                set {
                    year = value;
                }
            }
            int year;
        
        
            public bool IsLeapYear(int year)
            {
                return year%4== 0 ? true: false;
            }
            public void SetDate (int day, int month, int year)
            {
                this.day   = day;
                this.month = month;
                this.year  = year;
            }
        }

         

        Delegates / Events

        VB.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 
        
        
        'WithEvents can't be used on local variable
        Dim WithEvents MyButton As Button
        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

         

        C#

         

        delegate void MsgArrivedEventHandler(string message); 
        
        
        event MsgArrivedEventHandler MsgArrivedEvent; 
        
        
        //Delegates must be used with events in C#
        
        
        MsgArrivedEvent += new MsgArrivedEventHandler
          (My_MsgArrivedEventCallback);
        //Throws exception if obj is null
        MsgArrivedEvent("Test message");
        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);
        }

         

        Console I/O

        VB.NET

         

        'Special character constants
        vbCrLf, vbCr, vbLf, vbNewLine
        vbNullString
        vbTab
        vbBack
        vbFormFeed
        vbVerticalTab
        ""
        Chr(65) 'Returns 'A' 
        
        
        System.Console.Write("What's your name? ")
        Dim name As String = System.Console.ReadLine()
        System.Console.Write("How old are you? ")
        Dim age As Integer = Val(System.Console.ReadLine())
        System.Console.WriteLine("{0} is {1} years old.", name, age)
        'or
        System.Console.WriteLine(name & " is " & age & " years old.")
        
        Dim c As Integer
        c = System.Console.Read() 'Read single char
        System.Console.WriteLine(c) 'Prints 65 if user enters "A"

         

        C#

         

        //Escape sequences
        \n, \r
        \t
        \\
        \ 
        
        
        Convert.ToChar(65) //Returns 'A' - equivalent to Chr(num) in VB
        // or
        (char) 65 
        
        
        System.Console.Write("What's your name? ");
        string name = SYstem.Console.ReadLine();
        System.Console.Write("How old are you? ");
        int age = Convert.ToInt32(System.Console.ReadLine());
        System.Console.WriteLine("{0} is {1} years old.", name, age);
        //or
        System.Console.WriteLine(name + " is " + age + " years old."); 
        
        
        int c = System.Console.Read(); //Read single char
        System.Console.WriteLine(c); //Prints 65 if user enters "A"

         

        File I/O

        VB.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()

         

        C#

         

        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();

        相關教程
        免费看成年人视频大全_免费看成年人视频在线观看