vb.net – 如何使用公共函数从字节返回KB,MB和GB
我正在编写一个返回文件大小的“函数”(以B,KB,MB,GB为单位).
VB.Net代码总是首先以字节为单位获取大小,因此当文件大小(以字节为单位)小于100时,如果其>>则返回B. 1000然后我将它除以1000并返回KB.但是当它应该是MB时,我尝试除以1000000,它返回的大小总是比它应该的大2 MB! 有人可以告诉我我做错了什么! 例 我的文件大小是(15,570,550字节).. ..是…(14.8 MB) 所以当我通过这个函数运行它时它返回16MB! 代码 Public Function GetFileSize(ByVal TheFile As String,_ Optional ByVal ShowSizeType As Boolean = False) As String If TheFile.Length = 0 Then Return "" If Not System.IO.File.Exists(TheFile) Then Return "" '--- Dim TheSize As Integer = My.Computer.FileSystem.GetFileInfo(TheFile).Length Dim SizeType As String = "" '--- If TheSize < 1000 Then SizeType = "B" Else If TheSize < 1000000000 Then If TheSize < 1000000 Then SizeType = "KB" TheSize = TheSize / 1000 Else SizeType = "MB" TheSize = TheSize / 1000000 End If Else SizeType = "GB" End If End If '--- If ShowSizeType = True Then Return TheSize & SizeType Else Return TheSize End If End Function 解决方法
我会使用select case而不是if.
并且始终以最大的尺寸开始.“我在结核病时停止了,但是如果你需要的话你可以添加更多……” 我将Dim TheSize As Integer更改为“Dim TheSize As ULong”,否则大数字不起作用. 同时制作一个暗淡的“Dim DoubleBytes As Double”,你将在选择的情况下使用它. 首先你比较一下你拥有的字节数,让我们说mb“Case 1048576 To 1073741823” 然后在返回中使用FormatNumber设置要在后面显示的数字. “nuber 2将它设置为2后面.如28.11,将其更改为0,它将返回28”也因为你知道它会添加&回复. Private Sub Button1_Click(sender As Object,e As EventArgs) Handles Button1.Click MsgBox(GetFileSize("E:SoftwareTeamSpeak3-Client-win64-3.0.14.exe")) End Sub Dim DoubleBytes As Double Public Function GetFileSize(ByVal TheFile As String) As String If TheFile.Length = 0 Then Return "" If Not System.IO.File.Exists(TheFile) Then Return "" '--- Dim TheSize As ULong = My.Computer.FileSystem.GetFileInfo(TheFile).Length Dim SizeType As String = "" '--- Try Select Case TheSize Case Is >= 1099511627776 DoubleBytes = CDbl(TheSize / 1099511627776) 'TB Return FormatNumber(DoubleBytes,2) & " TB" Case 1073741824 To 1099511627775 DoubleBytes = CDbl(TheSize / 1073741824) 'GB Return FormatNumber(DoubleBytes,2) & " GB" Case 1048576 To 1073741823 DoubleBytes = CDbl(TheSize / 1048576) 'MB Return FormatNumber(DoubleBytes,2) & " MB" Case 1024 To 1048575 DoubleBytes = CDbl(TheSize / 1024) 'KB Return FormatNumber(DoubleBytes,2) & " KB" Case 0 To 1023 DoubleBytes = TheSize ' bytes Return FormatNumber(DoubleBytes,2) & " bytes" Case Else Return "" End Select Catch Return "" End Try End Function 我为它做了一个dll. Dim DoubleBytes As Double Default Public Property FormatBytes(ByVal BytesCaller As ULong) As String Get Try Select Case BytesCaller Case Is >= 1099511627776 DoubleBytes = CDbl(BytesCaller / 1099511627776) 'TB Return FormatNumber(DoubleBytes,2) & " TB" Case 1073741824 To 1099511627775 DoubleBytes = CDbl(BytesCaller / 1073741824) 'GB Return FormatNumber(DoubleBytes,2) & " GB" Case 1048576 To 1073741823 DoubleBytes = CDbl(BytesCaller / 1048576) 'MB Return FormatNumber(DoubleBytes,2) & " MB" Case 1024 To 1048575 DoubleBytes = CDbl(BytesCaller / 1024) 'KB Return FormatNumber(DoubleBytes,2) & " KB" Case 0 To 1023 DoubleBytes = BytesCaller ' bytes Return FormatNumber(DoubleBytes,2) & " bytes" Case Else Return "" End Select Catch Return "" End Try End Get Set(value As String) End Set End Property 如果你不想制作一个dll,你可以像使用这样的普通函数一样使用它. Private Sub Button1_Click(sender As Object,e As EventArgs) Handles Button1.Click MsgBox(FormatBytes(2000)) End Sub Dim DoubleBytes As Double Public Function FormatBytes(ByVal BytesCaller As ULong) As String Try Select Case BytesCaller Case Is >= 1099511627776 DoubleBytes = CDbl(BytesCaller / 1099511627776) 'TB Return FormatNumber(DoubleBytes,2) & " TB" Case 1073741824 To 1099511627775 DoubleBytes = CDbl(BytesCaller / 1073741824) 'GB Return FormatNumber(DoubleBytes,2) & " GB" Case 1048576 To 1073741823 DoubleBytes = CDbl(BytesCaller / 1048576) 'MB Return FormatNumber(DoubleBytes,2) & " MB" Case 1024 To 1048575 DoubleBytes = CDbl(BytesCaller / 1024) 'KB Return FormatNumber(DoubleBytes,2) & " KB" Case 0 To 1023 DoubleBytes = BytesCaller ' bytes Return FormatNumber(DoubleBytes,2) & " bytes" Case Else Return "" End Select Catch Return "" End Try End Function (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |