列出类的可用构造函数

Version >= 5

在 PowerShell 5.0+中，你可以通过调用不带括号的静态 new 方法列出可用的构造函数。

PS> [DateTime]::new

OverloadDefinitionsdatetime new(long ticks)
datetime new(long ticks, System.DateTimeKind kind)
datetime new(int year, int month, int day)
datetime new(int year, int month, int day, System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second)
datetime new(int year, int month, int day, int hour, int minute, int second, System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second, System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond, System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond,
System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second, int millisecond,
System.Globalization.Calendar calendar, System.DateTimeKind kind)

这与你可以用来列出任何方法的重载定义的技术相同

> 'abc'.CompareTo

OverloadDefinitionsint CompareTo(System.Object value)
int CompareTo(string strB)
int IComparable.CompareTo(System.Object obj)
int IComparable[string].CompareTo(string other)

对于早期版本，你可以创建自己的函数来列出可用的构造函数：

function Get-Constructor {
    [CmdletBinding()]
    param(
        [Parameter(ValueFromPipeline=$true)]
        [type]$type
    )

    Process {
        $type.GetConstructors() | 
        Format-Table -Wrap @{
            n="$($type.Name) Constructors"
            e={ ($_.GetParameters() | % { $_.ToString() }) -Join ", " }
        }
    }
}

用法：

Get-Constructor System.DateTime    
#Or [datetime] | Get-Constructor

DateTime ConstructorsInt64 ticks
Int64 ticks, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day
Int32 year, Int32 month, Int32 day, System.Globalization.Calendar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, System.Globalization.Calendar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.DateTimeKind kind
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.Globalization.Cal
endar calendar
Int32 year, Int32 month, Int32 day, Int32 hour, Int32 minute, Int32 second, Int32 millisecond, System.Globalization.Cal
endar calendar, System.DateTimeKind kind