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

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Текущая версия на 12:45, 26 мая 2010

Change file attribute for *.*

 
Imports System.IO
Module Module1
    Sub ProcessTree(ByVal Dir As String)
        Dim DirObj As New DirectoryInfo(Dir)
        Dim Files As FileInfo() = DirObj.GetFiles("*.*")
        Dim Dirs As DirectoryInfo() = DirObj.GetDirectories("*.*")
 
        Dim Filename As FileInfo
        For Each Filename In Files
            Try
                If (Filename.Attributes And FileAttributes.ReadOnly) Then
                    Filename.Attributes = (Filename.Attributes And Not FileAttributes.ReadOnly)
                End If
            Catch E As Exception
                Console.WriteLine("Error changing attribute for {0}", Filename.FullName)
                Console.WriteLine("Error: {0}", E.Message)
            End Try
        Next
        Dim DirectoryName As DirectoryInfo
        For Each DirectoryName In Dirs
            Try
                ProcessTree(DirectoryName.FullName)
            Catch E As Exception
                Console.WriteLine("Error accessing {0}", DirectoryName.FullName)
                Console.WriteLine("Error: {0}", E.Message)
            End Try
        Next
    End Sub
    Sub Main()
        ProcessTree("C:\")
    End Sub
End Module


Delete a file if exist

 
Imports System
Imports System.Windows.Forms
Imports System.Collections.Generic
Imports System.ruponentModel
Imports System.Drawing.Imaging
Imports System.Drawing
Public Class MainClass
   Shared Sub Main()
        Dim file_name As String = "test.wmf"
        " Delete the file if it exists.
        If Len(Dir$(file_name)) > 0 Then Kill(file_name)

   End Sub 
End Class


Delete *.Bak under a directory

 
Imports System.IO
Module Module1

    Sub DeleteFiles(ByVal Dir As String)
        Dim DirObj As New DirectoryInfo(Dir)
        Dim Files As FileInfo() = DirObj.GetFiles("*.bak")
        Dim Dirs As DirectoryInfo() = DirObj.GetDirectories("*.*")
 
        Dim Filename As FileInfo
        For Each Filename In Files
            Try
                File.Delete(Filename.FullName)
                Console.WriteLine("Deleted {0}", Filename.FullName)
            Catch E As Exception
                Console.WriteLine("Error deleting {0}", Filename.FullName)
                Console.WriteLine("Error: {0}", E.Message)
            End Try
        Next
        Dim DirectoryName As DirectoryInfo
        For Each DirectoryName In Dirs
            Try
                DeleteFiles(DirectoryName.FullName)
            Catch E As Exception
                Console.WriteLine("Error accessing {0}", DirectoryName.FullName)
                Console.WriteLine("Error: {0}", E.Message)
            End Try
        Next
    End Sub
    Sub Main()
        DeleteFiles("C:\")
    End Sub
End Module


English File Size

  
Public Class MainClass
    Public Shared Function ConvertBytes(ByVal Bytes As Long) As String
        If Bytes >= 1073741824 Then
            Return Format(Bytes / 1024 / 1024 / 1024, "#0.00") & " GB"
        ElseIf Bytes >= 1048576 Then
            Return Format(Bytes / 1024 / 1024, "#0.00") & " MB"
        ElseIf Bytes >= 1024 Then
            Return Format(Bytes / 1024, "#0.00") & " KB"
        ElseIf Bytes > 0 And Bytes < 1024 Then
            Return Fix(Bytes) & " Bytes"
        Else
            Return "0 Bytes"
        End If
    End Function
    Public Shared Sub Main()
        Dim objInfo As New System.IO.FileInfo("c:\a.dat")
        System.Console.WriteLine(ConvertBytes(objInfo.Length))
    End Sub
End Class


File Information

  

Imports System.IO
Imports System.Windows.Forms
<Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _
Partial Class Form1
    Inherits System.Windows.Forms.Form
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.txtDisplay = New System.Windows.Forms.TextBox
        Me.cmdCreate = New System.Windows.Forms.Button
        Me.cmdChangeDate = New System.Windows.Forms.Button
        Me.cmdGetInfo = New System.Windows.Forms.Button
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        "
        Me.txtDisplay.Anchor = CType((((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
                    Or System.Windows.Forms.AnchorStyles.Left) _
                    Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
        Me.txtDisplay.Location = New System.Drawing.Point(9, 79)
        Me.txtDisplay.Multiline = True
        Me.txtDisplay.ReadOnly = True
        Me.txtDisplay.ScrollBars = System.Windows.Forms.ScrollBars.Vertical
        Me.txtDisplay.Size = New System.Drawing.Size(280, 168)
        Me.txtDisplay.TabIndex = 9
        "
        Me.cmdCreate.Location = New System.Drawing.Point(9, 39)
        Me.cmdCreate.Size = New System.Drawing.Size(88, 24)
        Me.cmdCreate.TabIndex = 8
        Me.cmdCreate.Text = "Create"
        "
        Me.cmdChangeDate.Location = New System.Drawing.Point(201, 39)
        Me.cmdChangeDate.Size = New System.Drawing.Size(88, 24)
        Me.cmdChangeDate.TabIndex = 7
        Me.cmdChangeDate.Text = "Change Date"
        "
        Me.cmdGetInfo.Location = New System.Drawing.Point(105, 39)
        Me.cmdGetInfo.Size = New System.Drawing.Size(88, 24)
        Me.cmdGetInfo.TabIndex = 6
        Me.cmdGetInfo.Text = "Get Info"
        "
        Me.TextBox1.Location = New System.Drawing.Point(9, 11)
        Me.TextBox1.Size = New System.Drawing.Size(280, 21)
        Me.TextBox1.TabIndex = 5
        Me.TextBox1.Text = "c:\myfile.txt"
        "
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(298, 259)
        Me.Controls.Add(Me.txtDisplay)
        Me.Controls.Add(Me.cmdCreate)
        Me.Controls.Add(Me.cmdChangeDate)
        Me.Controls.Add(Me.cmdGetInfo)
        Me.Controls.Add(Me.TextBox1)
        Me.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)
        Me.PerformLayout()
    End Sub
    Friend WithEvents txtDisplay As System.Windows.Forms.TextBox
    Friend WithEvents cmdCreate As System.Windows.Forms.Button
    Friend WithEvents cmdChangeDate As System.Windows.Forms.Button
    Friend WithEvents cmdGetInfo As System.Windows.Forms.Button
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Private Sub cmdCreate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdCreate.Click
        Try
            Dim MyFile As New FileInfo("c:\myfile.txt")
            MyFile.Create().Close()
            Out("File created.")
        Catch err As Exception
            Out(err.Message)
        End Try
    End Sub
    Private Sub cmdGetInfo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdGetInfo.Click
        Try
            Dim MyFile As New FileInfo("c:\myfile.txt")
            Out("Length in bytes: " & MyFile.Length)
            Out("Attribute list: " & MyFile.Attributes.ToString)
            Out("Stored in: " & MyFile.DirectoryName)
            Out("Created: " & MyFile.CreationTime)
        Catch err As Exception
            Out(err.Message)
        End Try
    End Sub
    Public Sub Out(ByVal NewText As String) " Utility for displaying information.
        txtDisplay.Text &= vbNewLine & NewText
        txtDisplay.SelectionStart = txtDisplay.Text.Length - 1
        txtDisplay.ScrollToCaret()
    End Sub
    Private Sub cmdChangeDate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdChangeDate.Click
        Try
            Dim MyFile As New FileInfo("c:\myfile.txt")
            MyFile.LastWriteTime = DateTime.Today.Add(TimeSpan.FromDays(100))
            Out("Time updated.")
        Catch err As Exception
            Out(err.Message)
        End Try
    End Sub
End Class


File Time: created, last modified and accessed

 
Imports System
Imports System.IO
Public Class MainClass
   Shared Sub Main()
         Dim fileName As String
         fileName = "test.vb"
         
      Console.WriteLine( fileName & " exists" )
      " output when file or directory was created
      Console.WriteLine("Created : " & File.GetCreationTime(fileName) )
      " output when file or directory was last modified
      Console.WriteLine("Last modified: " & _
         File.GetLastWriteTime(fileName) )
      " output when file or directory was last accessed
      Console.WriteLine("Last accessed: " & _
         File.GetLastAccessTime(fileName) )
   End Sub " Main
End Class


Find Hidden File under a directory

 
Imports System
Imports System.IO
Public Class MainClass
  Shared Sub Main()
   Dim myDirectory As DirectoryInfo
    myDirectory = New DirectoryInfo("C:\")
    Dim aFile As FileInfo
    For Each aFile In myDirectory.GetFiles
        If (aFile.Attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
            Console.WriteLine("FOUND hidden file named " & aFile.FullName)
        End If        
    Next
   End Sub
  
End Class


Get Files under an Directory and print its Full Name and Length

 
Imports System
Imports System.IO
Public Class MainClass
  Shared Sub Main()
   Dim myDirectory As DirectoryInfo
    myDirectory = New DirectoryInfo("C:\")
    Dim aFile As FileInfo
    For Each aFile In myDirectory.GetFiles
        Console.WriteLine("The file named " & aFile.FullName & _
        " has length " & aFile.Length)
    Next
   End Sub
  
End Class


Get Invalid File Name Chars

 
Imports System
Imports System.IO
Imports System.Windows.Forms
Public Class MainClass
   Shared Sub Main()
        For Each ch As Char In Path.GetInvalidFileNameChars()
            Console.Write(ch & " ")
        Next ch
   End Sub 
End Class


Is it a File or a Directory

 
Imports System
Imports System.IO
Public Class MainClass
   Shared Sub Main()
         Dim fileName As String
         fileName = "test.vb"
         
         If File.Exists(fileName) Then
            Console.WriteLine( "File")
         ElseIf Directory.Exists(fileName) Then
            Console.WriteLine( "Directory")
         Else
            Console.WriteLine( "File for dir does not exist")
         End If
   End Sub " Main
End Class


Update file create time, last access time and last write time

 
Imports System.IO
Module Module1
    Sub Main()
       Try
           Dim FileObj As New FileInfo("test.dat")
           FileObj.CreationTime = DateTime.Now
           FileObj.LastAccessTime = DateTime.Now
           FileObj.LastWriteTime = DateTime.Now
           Console.WriteLine("test.dat date and time updated")
       Catch Ex As Exception
           Console.WriteLine("Error updating test.dat  " & Ex.Message)
       End Try
    End Sub
End Module