в 16:40, 26 мая 2010

2010-05-26T16:40:06Z

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2010-05-26T12:45:46Z

1 версия

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==Check if a directory does not exist, create a directory==

<source lang="vbnet">
Imports System.IO
Module Module1

Sub Main()
Try
If (Directory.Exists("D:\test01")) Then
Console.WriteLine("D:\test01 already exists")
Else
Directory.CreateDirectory("C:\test01")
End If
Console.WriteLine("Directories created")
Catch E As Exception
Console.WriteLine("Error creating directory")
Console.WriteLine("Error: {0}", E.Message)
End Try
End Sub
End Module

</source>

==Create directory with drive letter and without drive letter==

<source lang="vbnet">
Imports System.IO
Module Module1
Sub Main()
Console.WriteLine("Creating directories...")
Directory.CreateDirectory("D:\test01")
Directory.CreateDirectory("D:\Temp\Sample02")
Directory.CreateDirectory("Sample03")
Console.WriteLine("Directories created")
End Sub
End Module

</source>

==Delete a Directory==

<source lang="vbnet">
Imports System.IO
Module Module1

Sub Main()
Try
Directory.Delete("C:\Sample01", True)
Catch E As Exception
Console.WriteLine("Error deleting directory C:\Sample01")
Console.WriteLine("Error {0}", E.Message)
End Try
End Sub
End Module

</source>

==Get and set current working directory==

<source lang="vbnet">
Imports System.IO
Module Module1
Sub Main()
Console.WriteLine("Current directory is {0}", Directory.GetCurrentDirectory())
Directory.SetCurrentDirectory("C:\")
Console.WriteLine("Current directory is {0}", Directory.GetCurrentDirectory())
End Sub
End Module

</source>

==Get parent directory==

<source lang="vbnet">
Imports System.IO
Module Module1
Sub Main()
Dim Current As String
Dim Parent As DirectoryInfo
Try
Current = Directory.GetCurrentDirectory()
Parent = Directory.GetParent(Current)
Console.WriteLine("Current directory {0}", Current)
Console.WriteLine("Parent directory {0}", Parent.FullName)
Catch E As Exception
Console.WriteLine("Error determining parent directory")
Console.WriteLine(E.Message)
End Try
End Sub
End Module

</source>

==List all Directories under a directory==

<source lang="vbnet">
Imports System.IO
Module Module1
Sub Main()
Dim Root As New DirectoryInfo("C:\")
Dim Files As FileInfo() = Root.GetFiles("*.*")
Dim Dirs As DirectoryInfo() = Root.GetDirectories("*.*")
Console.WriteLine("Root Directories")
Dim DirectoryName As DirectoryInfo
For Each DirectoryName In Dirs
Try
Console.Write(DirectoryName.FullName)
Console.Write(" contains {0} files ", DirectoryName.GetFiles().Length)
Console.WriteLine(" and {0} subdirectories ", DirectoryName.GetDirectories().Length)
Catch E As Exception
Console.WriteLine("Error accessing")
End Try
Next
End Sub
End Module

</source>

==List all files under a directory==

<source lang="vbnet">
Imports System.IO
Module Module1
Sub Main()
Dim Root As New DirectoryInfo("C:\")
Dim Files As FileInfo() = Root.GetFiles("*.*")
Dim Dirs As DirectoryInfo() = Root.GetDirectories("*.*")
Console.WriteLine("Root Files")
Dim Filename As FileInfo
For Each Filename In Files
Try
Console.Write(Filename.FullName)
Console.Write(" Size: {0} bytes", Filename.Length)
Console.WriteLine(" Last use: {0}", Filename.LastAccessTime)
Catch E As Exception
Console.WriteLine("Error accessing File")
End Try
Next
End Sub
End Module

</source>

==Make Dictionary based on your own Object==

<source lang="vbnet">
Imports System
Imports System.Collections
Imports System.Collections.Generic
Public Class MainClass

Shared Sub Main(ByVal args As String())
Dim dict As New StudentDictionary
dict.Add("113-11-1111", New Student("A", "a"))
dict.Add("222-22-2222", New Student("B", "b"))
dict.Add("333-33-3333", New Student("C", "c"))
dict.Add("444-44-4444", New Student("D", "d"))
Dim student As Student = dict.Item("365-76-5476")
Console.WriteLine(student.ToString)
End Sub
End Class

Public Class Student
Private m_FirstName As String
Private m_LastName As String
Public Sub New(ByVal first_name As String, ByVal last_name As String)
m_FirstName = first_name
m_LastName = last_name
End Sub
Public Overrides Function ToString() As String
Return m_FirstName & " " & m_LastName
End Function
End Class
Public Class StudentDictionary
Inherits System.Collections.DictionaryBase
" Add a Dictionary entry.
Public Sub Add(ByVal new_key As String, ByVal new_student As Student)
Dictionary.Add(new_key, new_student)
End Sub
" Return an object with the given key.
Default Public Property Item(ByVal key As String) As Student
Get
Return DirectCast(Dictionary.Item(key), Student)
End Get
Set(ByVal Value As Student)
Dictionary.Item(key) = Value
End Set
End Property
" Return a collection containing the Dictionary"s keys.
Public ReadOnly Property Keys() As ICollection
Get
Return Dictionary.Keys
End Get
End Property
" Return a collection containing the Dictionary"s values.
Public ReadOnly Property Values() As ICollection
Get
Return Dictionary.Values
End Get
End Property
" Return True if the Dictionary contains this Student.
Public Function Contains(ByVal key As String) As Boolean
Return Dictionary.Contains(key)
End Function
" Remove this entry.
Public Sub Remove(ByVal key As String)
Dictionary.Remove(key)
End Sub
End Class

</source>

==Your own Generic List Dictionary ==

<source lang="vbnet">
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.Collections.Specialized

Public Class MainClass

Shared Sub Main(ByVal args As String())
Dim dict As New StudentListDictionary
dict.Add("111-11-1111", New Student("A", "A"))
dict.Add("333-22-3333", New Student("B", "B"))
dict.Add("444-44-4444", New Student("C", "C"))
dict.Add("555-55-5555", New Student("D", "D"))
Dim student As Student = dict.Item("111-11-1111")
Console.WriteLine(student.ToString)
End Sub
End Class

Public Class Student
Private m_FirstName As String
Private m_LastName As String
Public Sub New(ByVal first_name As String, ByVal last_name As String)
m_FirstName = first_name
m_LastName = last_name
End Sub
Public Overrides Function ToString() As String
Return m_FirstName & " " & m_LastName
End Function
End Class
Public Class StudentListDictionary
Inherits ListDictionary
" Add a Dictionary entry.
Public Shadows Sub Add(ByVal new_key As String, ByVal new_student As Student)
MyBase.Add(new_key, new_student)
End Sub
" Return an object with the given key.
Default Public Shadows Property Item(ByVal key As String) As Student
Get
Return DirectCast(MyBase.Item(key), Student)
End Get
Set(ByVal Value As Student)
MyBase.Item(key) = Value
End Set
End Property
" Return True if the Dictionary contains this Student.
Public Shadows Function Contains(ByVal key As String) As Boolean
Return MyBase.Contains(key)
End Function
" Remove this entry.
Public Shadows Sub Remove(ByVal key As String)
MyBase.Remove(key)
End Sub
End Class

</source>

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VB.Net/Data Structure/Dictionary - История изменений

в 16:40, 26 мая 2010

Admin: 1 версия