因为这个经常出现，我为它定义了一个函数。我默认使用区分大小写、基于正则表达式的匹配，但我添加了针对文字文本和忽略大小写的开关。

# Find and replace text in each pipeline string.  Omit the -Replace parameter to delete
# text instead.  Use the -SimpleMatch switch to work with literal text instead of regular
# expressions.  Comparisons are case-sensitive unless the -IgnoreCase switch is used.
Filter Edit-String {
    Param([string]$Find, [string]$Replace='', [switch]$SimpleMatch, [switch]$IgnoreCase) 

    if ($SimpleMatch) {
        if ($IgnoreCase) {
            return $_.Replace($Find, $Replace,
                [System.StringComparison]::OrdinalIgnoreCase)
        }
        return $_.Replace($Find, $Replace)
    }
    if ($IgnoreCase) {
        return $_ -replace $Find, $Replace
    }
    return $_ -creplace $Find, $Replace
}

Set-Alias replace Edit-String
Set-Alias sc Set-Content  

使用

# 1 file
$f = a.txt; gc $f | replace '[MYID]' 'MyValue' -SimpleMatch | sc $f

# 0 to many files
gci *.txt | % { gc $_ | replace '\[MYID\]' 'MyValue' | sc $_ }

# Several replacements chained together
... | replace '[1-9]' T | replace a b -IgnoreCase | replace 'delete me' | ...

# Alias cheat sheet
#  gci Get-ChildItem
#  gc  Get-Content
#  sc  Set-Conent
#  %   ForEach-Object

如果需要替换多个文件中的字符串:

值得注意的是，这里发布的不同方法在完成所需时间方面可能有很大不同。对我来说，我经常有大量的小文件。为了测试哪个性能最好，我在40,693个单独的文件中提取了5.52 GB(5,933,604,999字节)的XML，并运行了我在这里找到的三个答案:

## 5.52 GB (5,933,604,999 bytes) of XML files (40,693 files) 
$xmls = (Get-ChildItem -Path "I:\TestseT\All_XML" -Recurse -Filter *.xml).FullName

#### Test 1 - Plain Replace
$start = Get-Date
foreach ($xml in $xmls) {
    (Get-Content $xml).replace("'", " ") | Set-Content $xml
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 103.725113128333

#### Test 2 - Replace with -Raw
$start = Get-Date
foreach ($xml in $xmls) {
    (Get-Content $xml -Raw).replace("'", " ") | Set-Content $xml
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 10.1600227983333

#### Test 3 - .NET, System.IO
$start = Get-Date
foreach ($xml in $xmls) {
    $txt = [System.IO.File]::ReadAllText("$xml").Replace("'"," ") 
    [System.IO.File]::WriteAllText("$xml", $txt)
}
$end = Get-Date
New-TimeSpan –Start $Start –End $End
# TotalMinutes: 5.83619516833333

用途(V3版本):

(Get-Content c:\temp\test.txt).replace('[MYID]', 'MyValue') | Set-Content c:\temp\test.txt

对于V2:

(Get-Content c:\temp\test.txt) -replace '\[MYID\]', 'MyValue' | Set-Content c:\temp\test.txt

使用PowerShell中的当前工作目录，这对我来说很有效。您需要使用FullName属性，否则它将在PowerShell版本5中不起作用。我需要在所有CSPROJ文件中更改目标. net框架版本。

gci -Recurse -Filter *.csproj |
% { (get-content "$($_.FullName)")
.Replace('<TargetFramework>net47</TargetFramework>', '<TargetFramework>net462</TargetFramework>') |
 Set-Content "$($_.FullName)"}

你可以尝试这样做:

$path = "C:\testFile.txt"
$word = "searchword"
$replacement = "ReplacementText"
$text = get-content $path 
$newText = $text -replace $word,$replacement
$newText > $path

(Get-Content file.txt) | 
Foreach-Object {$_ -replace '\[MYID\]','MyValue'}  | 
Out-File file.txt

注意(Get-Content file.txt)周围的括号是必需的:

Without the parenthesis the content is read, one line at a time, and flows down the pipeline until it reaches out-file or set-content, which tries to write to the same file, but it's already open by get-content and you get an error. The parenthesis causes the operation of content reading to be performed once (open, read and close). Only then when all lines have been read, they are piped one at a time and when they reach the last command in the pipeline they can be written to the file. It's the same as $content=content; $content | where ...