If statement vb脚本if语句

如果文件中必须包含的单词不存在，我想用VB编辑一个文件。 当执行这个文件时，如果条件为真，我想什么都不做，但所有的文件内容都被删除了

Const ForReading = 1
Const ForWriting = 2

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("C:\path\to\file.html", ForReading)

strText = objFile.ReadAll
objFile.Close
strSearchFor = "this word must to exist"

If InStr(1, strText, strSearchFor) > 0 then
    'do nothing
else
    strNewText = Replace(strText,"this word must to delete","this word must to exist" )
End If
Set objFile = objFSO.OpenTextFile("C:\path\to\file.html", ForWriting)
objFile.WriteLine strNewText
objFile.Close

---

这是因为当您的条件为true时，strNewText将为null。并且仍然用空的

strNewText

替换

strText

。 将您的作品放在

if（）

一侧。因此，它将解决问题

Const ForReading = 1
Const ForWriting = 2

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("C:\path\to\file.html", ForReading)

strText = objFile.ReadAll
objFile.Close
strSearchFor = "this word must to exist"

    If InStr(1, strText, strSearchFor) > 0 then
        'do nothing
    else
        strNewText = Replace(strText,"this word must to delete","this word must to exist" )

        Set objFile = objFSO.OpenTextFile("C:\path\to\file.html", ForWriting)
        objFile.WriteLine strNewText
        objFile.Close
    End If