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包装在PSInvalidCastException中时捕获特定异常的正确方法

powershell-v5.0 exception-handling exception powershell

JohnLBevan · 技术社区 · 6 年前

<?xml version="1.0" encoding="utf-8"?>
<root><nodeNotClosed></root>

此PowerShell将捕获无效的强制转换异常:

$path = 'c:\temp\invalidXml.xml'
try {
    $myXml = [xml](Get-Content -Path $path -Raw)
} catch [System.Management.Automation.PSInvalidCastException] {
    "'$path' is not a valid XML document"
}

但是,我只希望catch块捕获与将文件内容转换为XML相关的问题;而不是其他类型的转换异常。可以这样做:

$path = 'c:\temp\invalidXml.xml'
try {
    $myXml = [xml](Get-Content -Path $path -Raw)
    #some other code which may cause a PSInvalidCastException to be thrown. e.g.
    #$myDate = [DateTime]'not a date'
} catch [System.Management.Automation.PSInvalidCastException] {
    if ($_.Exception.InnerException -as [System.Xml.XmlException]) {
        "'$path' is not a valid XML document"
    } else {
        throw #not the exception we wanted to catch, so throw it back
    }
}

$path = 'c:\temp\invalidXml.xml'
try {
    $myXml = [xml](Get-Content -Path $path -Raw)
} catch [System.Xml.XmlException] {
    "'$path' is not a valid XML document"
}