VB.Net/File Directory/Serialize Object — различия между версиями

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Текущая версия на 12:45, 26 мая 2010

Save Serializable Object to binary file: create a sequential-access file

 
Imports System.IO
Imports System.Collections
Imports System.Windows.Forms
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization
Public Class MainClass
   Public Shared Sub Main()
         Dim formatter As BinaryFormatter = New BinaryFormatter()
         Dim output As FileStream
         Dim fileName As String = "test.dat"
         Dim employee As Employee = New Employee("First Name", "Last Name")
         Try
            output = New FileStream(fileName,FileMode.OpenOrCreate, FileAccess.Write)
  
            formatter.Serialize(output, employee)
            output.Close()
  
         Catch fileException As FileNotFoundException
            Console.WriteLine("File Does Not Exits")
         Catch serializableException As SerializationException
            Console.WriteLine("Error Writing to File")
         Catch formattingException As FormatException
            Console.WriteLine("Invalid Format")
         Catch e As IOException
            Console.WriteLine("Cannot close file")
         End Try
   End Sub
End Class
<Serializable()> Public Class Employee
   Private firstName, lastName As String
   Public Sub New(ByVal first As String, ByVal last As String)
      firstName = first
      lastName = last
   End Sub 
   Public Overrides Function ToString() As String
      Return firstName & " " & lastName
   End Function 
End Class


Serializable Person Object

  
Imports System.IO
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization.Formatters.Soap
Public Class MainClass
    Public Shared Sub Main()
        Dim Bob As New SerializablePerson("Bob", 34, 5.25)
        Dim fs As New FileStream("c:\bob.dat", FileMode.Create)
        Dim f As System.Runtime.Serialization.IFormatter
        f = New SoapFormatter()
        "f = New BinaryFormatter()
        f.Serialize(fs, Bob)
        fs.Close()
        Bob = Nothing
        fs = New FileStream("c:\bob.dat", FileMode.Open)
        Bob = CType(f.Deserialize(fs), SerializablePerson)
        System.Console.WriteLine(Bob.Name)
        fs.Close()
    End Sub
End Class
<Serializable()> Public Class SerializablePerson
    Public Name As String
    Public Age As Integer
    Public Height As Integer
    Public Sub New()
    End Sub
    Public Sub New(ByVal Name As String, ByVal Age As String, _
      ByVal Height As String)
        Me.Name = Name
        Me.Age = Age
        Me.Height = Height
    End Sub
End Class


Serialize Data to Binary and XML at the same time

 
Imports System
Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports System.Runtime.Serialization.Formatters.Binary
public class MainClass
   Shared Sub Main()
      "Create Connection object
      Dim thisConnection As New SqlConnection("server=(local)\SQLEXPRESS;" & _
          "integrated security=sspi;database=MyDatabase")
      Dim sql As String = "SELECT * FROM Employee"
      Dim fs As New FileStream("Employee.bin",FileMode.Create)

      Try
         " Create Data Adapter
         Dim da As New SqlDataAdapter
         da.SelectCommand = New SqlCommand(sql, thisConnection)
         " Create and fill Dataset
         Dim ds As New DataSet
         da.Fill(ds, "Employee")
         " Extract DataSet to XML file
         ds.WriteXml("Employee.xml")
         " Create binary formatter
         Dim bf As New BinaryFormatter()
         " Specify binary serialization for dataset
         ds.RemotingFormat = SerializationFormat.Binary
         " Output dataset
         bf.Serialize(fs, ds)
      Catch ex As SqlException
         Console.WriteLine("Error: " & ex.ToString())
      Finally
         fs.Close()
         thisConnection.Close()
         Console.WriteLine("Connection Closed")
      End Try
   End Sub
End Class


Serialize Object to XML Stream and output to screen

 
Imports System
Imports System.Xml
Imports System.Xml.Serialization
 
Public Class MainClass
    Shared Sub Main(  )
       Dim serialize As XmlSerializer = _
              New XmlSerializer(GetType(Order))
       Dim MyMovieOrder As Order = _
              New Order("Name", 101, 10)
       serialize.Serialize(Console.Out, MyMovieOrder)
       Console.Out.WriteLine()
    End Sub
  
End Class
Public Class Order
    Public name As String
    Public id As Integer
    Public quantity As Integer
    Public Sub New()
    End Sub
    Public Sub New(ByVal name As String, _
                   ByVal id As Integer, _
                   ByVal quantity As Integer)
        Me.name = name
        Me.id = id
        Me.quantity = quantity
    End Sub
End Class


Serialize to Xml

  

Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
    Public Class MainClass
        Public Shared Sub Main()
            Dim roster = New EmployeeCollection(DateTime.Now)
            Dim employees = New Employee() _
                {New Employee With {.Id = 1, .Name = "A", _
                                    .Title = "Coder", _
                                    .HireDate = DateTime.Now, _
                                    .HourlyRate = 100.0}, _
                 New Employee With {.Id = 4, .Name = "B", _
                                    .Title = "Coder", _
                                    .HireDate = DateTime.Now, _
                                    .HourlyRate = 100.75}}
            roster.Employees = employees
            Dim serializer As New XmlSerializer(GetType(EmployeeCollection))
            Dim fs As New FileStream("EmployeeCollection.xml", FileMode.Create)
            serializer.Serialize(fs, roster)
            fs.Close()
            roster = Nothing
            fs = New FileStream("EmployeeCollection.xml", FileMode.Open)
            roster = DirectCast(serializer.Deserialize(fs), EmployeeCollection)
            serializer.Serialize(Console.Out, roster)
        End Sub
    End Class
    <XmlRoot("EmployeeCollection")> _
    Public Class EmployeeCollection
        <XmlElement(ElementName:="LastUpdated", datatype:="date")> _
        Public LastUpdated As DateTime
        <XmlArray("Employees"), XmlArrayItem("Employee")> _
        Public Employees As Employee()
        Public Sub New()
        End Sub
        Public Sub New(ByVal update As DateTime)
            Me.LastUpdated = update
        End Sub
    End Class
    Public Class Employee
        <XmlElement("Name")> _
        Public Name As String = String.Empty
        <XmlElement("Title")> _
        Public Title As String = String.Empty
        <XmlElement(ElementName:="HireDate", datatype:="date")> _
        Public HireDate As DateTime = Date.MinValue
        <XmlElement("HourlyRate")> _
        Public HourlyRate As Decimal = 0
        <XmlAttribute(AttributeName:="id", DataType:="integer")> _
        Public Id As String = String.Empty
        Public Sub New()
        End Sub
        Public Sub New(ByVal employeName As String, ByVal employeeTitle As String, ByVal employeeHireDate As DateTime, ByVal employeeHourlyRate As Decimal)
            Me.Name = employeName
            Me.Title = employeeTitle
            Me.HireDate = employeeHireDate
            Me.HourlyRate = employeeHourlyRate
        End Sub
    End Class


Simple Serializable Person Object

  
Imports System.IO
Public Class MainClass
    Public Shared Sub Main()
        Dim Bob As New Person("Bob", 34, 5.25)
        Bob.SaveToFile("c:\a.bin")
        Bob = Nothing
        Bob = Person.LoadFromFile("c:\a.bin")
        System.Console.WriteLine(Bob.Name)
    End Sub
End Class
Public Class Person
    Public Name As String
    Public Age As Integer
    Public Height As Integer
    Public Sub New()
    End Sub
    Public Sub New(ByVal Name As String, ByVal Age As String, ByVal Height As String)
        Me.Name = Name
        Me.Age = Age
        Me.Height = Height
    End Sub
    Public Sub SaveToFile(ByVal Filename As String)
        Dim fs As New FileStream(Filename, FileMode.Create)
        Dim w As New BinaryWriter(fs)
        w.Write(Name)
        w.Write(Age)
        w.Write(Height)
        w.Close()
    End Sub
    Public Shared Function LoadFromFile(ByVal Filename As String) As Person
        Dim fs As New FileStream(Filename, FileMode.Open)
        Dim r As New BinaryReader(fs)
        Dim NewPerson As New Person()
        NewPerson.Name = r.ReadString()
        NewPerson.Age = r.ReadInt32()
        NewPerson.Height = r.ReadInt32()
        r.Close()
        Return NewPerson
    End Function
End Class