Question

#include <iostream>

template <class T> struct TYPE;

template <class T> TYPE<T> foo(TYPE<T> &, TYPE<T> &);
template <class T> TYPE<T> bar(TYPE<T> &, TYPE<T> &);

template <class T>
struct TYPE
{
  friend TYPE<T> foo<> ( TYPE<T> &, TYPE<T> & );
  friend TYPE<T> bar<> ( TYPE<T> &, TYPE<T> & );
};

template <class T> TYPE<T> foo(TYPE<T> &, TYPE<T> &) { TYPE<T> res; std::cout << "1" << std::endl; return res; }
template <class T> TYPE<T> bar(TYPE<T> &, TYPE<T> &) { TYPE<T> res; std::cout << "2" << std::endl; return res; }

struct CLASS
{
  typedef TYPE<int> (*ptr_to_function) ( TYPE<int> &, TYPE<int> & );

  ptr_to_function  ptr_to_foo = foo<int>; // Initialise pointer to foo
  ptr_to_function  ptr_to_bar = bar<int>;

  void calculate () {
    procedure ( ptr_to_bar );
    procedure ( ptr_to_foo );
  }

  void procedure ( ptr_to_function fun )
  {
    TYPE<int> x;
    fun(x, x);
  }
};

int main()
{
    CLASS c;
    c.calculate();
}

该功能正常运行，但不适用于New-ItemProperty：

控制台输出：

Type paths: "D:\", "D:\1", "D:\2"

New-ItemProperty : Cannot convert "System.String[]" to the type "System.String"
required bt parameter "Name". Specified metod is not supported.
line:12 char:83
+ ... KCU:\Software\Microsoft\DirectX\UserGpuPreferences -Name $app -Proper ...
+                                                              ~~~~
    + CategoryInfo          : InvalidArgument: (:) [New-ItemProperty], ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgument,Microsoft.PowerShell.Commands.NewItemPropertyCommand

如果我想将路径设置为参数（用逗号分隔并用引号引起来），应该如何修改该功能？

Answer 1

在将用户输入传递到函数之前先对其进行清理/准备，然后使用循环处理函数参数（因为New-ItemProperty需要一个字符串，而不是字符串数组）。< / p>

function Write-GpuPreference {
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory=$true)]
        [string[]]$Preference
    )

    Begin {
        $path  = 'HKCU:\Software\Microsoft\DirectX\UserGpuPreferences'
        $value = 'GpuPreference=2;'
    }

    Process {
        $Preference | Select-Object -Unique | ForEach-Object {
            New-ItemProperty -Path $path -Name $_ -PropertyType String -Value $value -Force
        }
    }
}

$app = Read-Host -Prompt " "
$app = $app.Replace('"', '').Split(',').Trim()
Write-GpuPreference $app

将“ System.String []”转换为类型“ System.String”

1 个答案: