Question

我想在userform的文本框中显示一个textlog字符串。

代码可能如下所示：

Dim public textlog as string

sub button1_click()
' do some action
textlog = textlog & event_string & vbCrLf
'event_string might exceed more than 2 line 
textlog = textlog & "button1 action" & vbCrLf
userform1.textbox1.text = textlog 
end sub

sub button2_click()
' do some action
textlog = textlog & event_string & vbCrLf
'event_string might exceed more than 2 line 
textlog = textlog & "button2 action" & vbCrLf
userform1.textbox1.text = textlog 
end sub

但是，文本框应该只包含20行信息，而我的我的课本内容将超过20行。

如何在textbox1中仅显示最新（最后）20行文本日志？

Answer 1

您可以使用此功能仅返回字符串的最后N行，然后在文本框中显示该行。

请注意，您必须指定换行符是什么。根据您的具体应用，可能是vbCrLf，vbCr，vbLf，甚至是其他分隔符。

Function GetLastLines(ByVal s As String, ByVal nLinesToDisplay As Long, _
    Optional ByVal lineBreakChar As String = vbCrLf)

    'Split the string into an array
    Dim splitString() As String
    splitString = Split(s, lineBreakChar)

    'How many lines are there?
    Dim nLines As Long
    nLines = UBound(splitString) + 1

    If nLines <= nLinesToDisplay Then
        'No need to remove anything. Get out.
        GetLastLines = s
        Exit Function
    End If

    'Collect last N lines in a new array
    Dim lastLines() As String
    ReDim lastLines(0 To nLinesToDisplay - 1)
    Dim i As Long
    For i = 0 To UBound(lastLines)
        lastLines(i) = splitString(i + nLines - nLinesToDisplay)
    Next i

    'Join the lines array into a single string
    GetLastLines = Join(lastLines, lineBreakChar)
End Function

使用示例：

MsgBox GetLastLines( _
    "line 1" & vbCrLf & "line 2" & vbCrLf & "line 3" & vbCrLf _
        & "line 4" & vbCrLf & "line 5" & vbCrLf & "line 6", _
    4, vbCrLf)

仅显示最后4行：

enter image description here

请注意，这假设您的最后一行不由换行符终止。如果是，那么你可以调整代码来处理它。

或者，您可以使用Excel的内置SUBSTITUTE函数，这在此特定情况下很有用，因为它可以找到给定字符的特定实例。因此，您可以使用单行代码来代替构建数组：

Function GetLastLines2(ByVal s As String, ByVal nLinesToDisplay As Long, _
    Optional ByVal lineBreakChar As String = vbCrLf)

    'An arbitrary character that will never be in your input string:
    Dim delim As String: delim = Chr(1)

    'How many lines are there?
    Dim nLines As Long
    nLines = UBound(Split(s, lineBreakChar)) + 1

    If nLines <= nLinesToDisplay Then
        'No need to remove anything. Get out.
        GetLastLines2 = s
        Exit Function
    End If

    'Replace one line break with delim, split the string on it, 
    'return only second part:
    GetLastLines2 = Split( _
        WorksheetFunction.Substitute( _
            s, lineBreakChar, delim, nLines - nLinesToDisplay), _
        delim)(1)

End Function

Answer 2

A = "Cat" & vbcrlf & "Tiger" & vbcrlf & "Lion" & vbcrlf & "Shark hunting florida lynxs" & vbcrlf & "Leopard" & vbcrlf & "Cheetah"
A= StrReverse(A)
NumLines = 3
i=1
For X = 1 to NumLines
    i = Instr(i, A, vbcr) + 1
Next

Msgbox StrReverse(Left(A, i - 1))

这是一个从文件的顶部或底部剪切或留下行的程序。

使用

<强>剪切

filter cut {t|b} {i|x} NumOfLines

从文件的顶部或底部剪切行数。

t - top of the file
b - bottom of the file
i - include n lines
x - exclude n lines

示例

cscript //nologo filter.vbs cut t i 5 < "%systemroot%\win.ini"

脚本

Set rs = CreateObject("ADODB.Recordset") With rs .Fields.Append "LineNumber", 4 .Fields.Append "Txt", 201, 5000 .Open LineCount = 0 Do Until Inp.AtEndOfStream LineCount = LineCount + 1 .AddNew .Fields("LineNumber").value = LineCount .Fields("Txt").value = Inp.readline .UpDate Loop .Sort = "LineNumber ASC" If LCase(Arg(1)) = "t" then If LCase(Arg(2)) = "i" then .filter = "LineNumber < " & LCase(Arg(3)) + 1 ElseIf LCase(Arg(2)) = "x" then .filter = "LineNumber > " & LCase(Arg(3)) End If ElseIf LCase(Arg(1)) = "b" then If LCase(Arg(2)) = "i" then .filter = "LineNumber > " & LineCount - LCase(Arg(3)) ElseIf LCase(Arg(2)) = "x" then .filter = "LineNumber < " & LineCount - LCase(Arg(3)) + 1 End If End If Do While not .EOF Outp.writeline .Fields("Txt").Value .MoveNext Loop End With

裁剪字符串的最后N行以显示在userform文本框中

2 个答案: