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Imports System
' 此类代表压缩文件中的某一个项目（也就是某一个档案的压缩数据）。
Public Class ZipEntry
' 私有字段。
Private thisSize As Int32
Private thisCompressedSize As Int32
Private thisDosTime As Int32 ' 以 Int 来表示的时间。
Private thisNameLength As Int16 ' 变动大小名称的长度。
Private thisCrc() As Byte ' 16 个 CRC 字节的数组。
Private thisName As String
' 使用指定的名称于压缩文件中建立一个项目。
' 所指定的名称可能会内含以 '/' 分隔的目录。
Public Sub New(ByVal newName As String)
If newName Is Nothing Then
' 错误的输入项目。
Throw New System.ArgumentNullException()
End If
Me.ModifiedDateTime = System.DateTime.Now
Me.Name = newName
Me.thisSize = 0
Me.thisCompressedSize = 0
Me.thisCrc = New Byte(15) {}
End Sub 'New
Public Property DosTime() As Int32
Get
Return thisDosTime
End Get
Set(ByVal value As Int32)
Me.thisDosTime = value
End Set
End Property
Public Property NameLength() As Int16
Get
Return thisNameLength
End Get
Set(ByVal value As Int16)
' 检查此值是否大于 16 个字节。
If CType(value, Int16) > &HFFFF Then
Throw New ArgumentOutOfRangeException()
End If
Me.thisNameLength = value
End Set
End Property
' 取得或设定项目最后一次的修改时间。
Public Property ModifiedDateTime() As DateTime
Get
Dim sec As Integer = 2 * (thisDosTime And &H1F)
Dim min As Integer = (thisDosTime >> 5) And &H3F
Dim hrs As Integer = (thisDosTime >> 11) And &H1F
Dim day As Integer = (thisDosTime >> 16) And &H1F
Dim mon As Integer = (thisDosTime >> 21) And &HF
Dim year As Integer = ((thisDosTime >> 25) And &H7F) + 1980 ' since 1900
Return New System.DateTime(year, mon, day, hrs, min, sec)
End Get
Set(ByVal value As DateTime)
DosTime = ((CType(value.Year, Int32) - 1980 And &H7F) << 25) _
Or (CType(value.Month, Int32) << 21) Or _
(CType(value.Day, Int32) << 16) Or (CType(value.Hour, Int32) << 11) _
Or (CType(value.Minute, Int32) << 5) Or (CType(value.Second, Int32) >> 1)
End Set
End Property
' 传回项目的名称。 项目中的路径部分固定会以斜线 '/' 来分隔。
Public Property Name() As String
Get
Return thisName
End Get
Set(ByVal value As String)
' 检查此值是否大于 16 个字节或是为 null。
If Value Is Nothing OrElse Value.Length > &HFFFFL Then
Throw New ArgumentOutOfRangeException()
End If
If Value.Length <> 0 Then
thisName = Value
thisNameLength = CType(Value.Length, Int16)
End If
End Set
End Property
' 取得或设定未压缩数据的大小。
Public Property Size() As Int32
Get
Return thisSize
End Get
Set(ByVal value As Int32)
' 检查此值是否大于 32 个字节。
If CType(value, Int32) > Int32.MaxValue Then
Throw New ArgumentOutOfRangeException()
End If
thisSize = CType(value, Int32)
End Set
End Property
' 取得或设定压缩数据的大小。
Public Property CompressedSize() As Int32
Get
Return thisCompressedSize
End Get
Set(ByVal value As Int32)
' 检查此值是否大于 32 个字节。
If CType(value, Int32) > Int32.MaxValue Then
Throw New ArgumentOutOfRangeException()
End If
Me.thisCompressedSize = CType(value, Int32)
End Set
End Property
' 取得或设定压缩数据的 crc。
Public Function GetCrc() As Byte()
Return thisCrc
End Function 'GetCrc
Public Sub SetCrc(ByVal value() As Byte)
' 检查值数组的长度是否大于 16 。
If value.Length <> thisCrc.Length Then
Throw New ArgumentOutOfRangeException()
End If
thisCrc = value
End Sub 'SetCrc
End Class 'ZipEntry
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