如何在文件名中的特定字符范围内搜索字符串？

Question

如何通过DirectoryInfo类在文件名中查找特定范围内的字符串？

我只需要选择字符范围为 22 到 29 的“inscriz”文件

这是我的代码：

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Try
            Dim folder As New DirectoryInfo(sourceDirectory)
            Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim xlsList = folder.EnumerateFiles("*.XLS").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim xlsxList = folder.EnumerateFiles("*.XLSX").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim csvList = folder.EnumerateFiles("*.csv").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            ' Copy pdf files.
            For Each file In pdfList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy XLS files.
            For Each file In xlsList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy XLSX files.
            For Each file In xlsxList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy CSV files.
            For Each file In csvList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Answer 1

转换这个：

Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)

到这里：

Dim pdfList = folder.EnumerateFiles("*.PDF").
    Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date AndAlso 
          fi.Name.Length >= 29 AndAlso fi.Name.Substring(22,7) = "inscriz" )

并对其他文件类型执行相同操作。

我将添加一个注释，即问题文本说要在字符 22 和 29 之间的范围内搜索（长度为 7 个字符），以查找也是 7 个字符的文本集。在这种情况下，我们可以做一个简单的相等比较。如果范围更长，我们将改用.Contains()。

---

我也可能很想这样做，以避免重复，但有一个很好的论点可以证明这也太矫枉过正了：

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Dim from_date As DateTime = DateTime.Now.AddHours(-24)
    Dim to_date As DateTime = DateTime.Now.AddHours(+24)
    Dim folder As New DirectoryInfo(sourceDirectory)

    Dim cp As Action(Of String) = 
    Sub(fileType) 
        Dim files = folder.EnumerateFiles(fileType).
            Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date AndAlso 
                fi.Name.Length >= 29 AndAlso fi.Name.Substring(22,7) = "inscriz" )

        For Each file In xlsList
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
    End Sub

    Try
        cp("*.PDF")
        cp("*.XLS")
        cp("*.XLSX")
        cp("*.csv")
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Answer 2

正则表达式变体：

Dim R as new Regex("^.{21}inscriz")
Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) 
    fi.CreationTime >= fromDate AndAlso fi.CreationTime <= to_date AndAlso
    R.Match(fi.Name).Success)

Answer 3

为什么不在文件过滤器中包含这个条件？

Dim pdfList = folder.EnumerateFiles("??????????????????????inscriz*.PDF") .Where(
    Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)

通过为重复部分创建一个Sub，可以使代码更具可读性

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim folder As New DirectoryInfo(sourceDirectory)

        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Dim datePredicate As Func(Of FileInfo, Boolean) =
            Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date

        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.PDF", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.XLS", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.XLSX", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.csv", datePredicate)
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Private Sub CopyFiles(source As DirectoryInfo, destDirectory As String,
                      fileFilter As String,
                      dateFilter As Func(Of FileInfo, Boolean))

    Dim fileList = source.EnumerateFiles(fileFilter).Where(dateFilter)

    For Each file In fileList
        file.CopyTo(Path.Combine(destDirectory, file.Name))
    Next
End Sub

Answer 4

使用Substring，并使用可重用谓词简化代码以减少维护

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Dim searchString = "inscriz"
        Dim folder As New DirectoryInfo(sourceDirectory)
        Dim fileSearchPredicate As Func(Of FileInfo, Boolean) =
            Function(fi)
                Return fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date _
                AndAlso fi.Name.Length >= 29 AndAlso fi.Name.Substring(21, 8).Contains(searchString)
            End Function
        Dim pdfList = folder.EnumerateFiles("*.PDF").Where(fileSearchPredicate)
        Dim xlsList = folder.EnumerateFiles("*.XLS").Where(fileSearchPredicate)
        Dim xlsxList = folder.EnumerateFiles("*.XLSX").Where(fileSearchPredicate)
        Dim csvList = folder.EnumerateFiles("*.csv").Where(fileSearchPredicate)
        For Each file In pdfList ' Copy pdf files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In xlsList ' Copy XLS files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In xlsxList ' Copy XLSX files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In csvList ' Copy CSV files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub