Error while implementing using in powershell - powershell

Question

Following this post when I am trying to implement Using functionality in Powershell
Function cUsing {
param (
[System.IDisposable] $inputObject = $(throw "The parameter -inputObject is required."),
[ScriptBlock] $scriptBlock = $(throw "The parameter -scriptBlock is required.")
)
Try { &$scriptBlock }
Finally {
if ($inputObject -ne $null) {
if ($inputObject.psbase -eq $null) {
$inputObject.Dispose()
} else {
$inputObject.psbase.Dispose()
}
}
}
}
cUsing($sqlConnection = New-Object System.Data.SqlClient.SqlConnection)
{
$sqlConnection.ConnectionString = "Server=myserver; Database=master; Integrated Security= True"
$sqlConnection.Open()
$sqlCmd = New-Object System.Data.SqlClient.SqlCommand
$sqlCmd.CommandText = "SELECT STATEMENT"
$sqlCmd.Connection = $sqlConnection
$dsValues = New-Object System.Data.DataSet
$daValues = New-Object System.Data.SqlClient.SqlDataAdapter($sqlCmd)
$daValues.Fill($dsValues)
Write-Host $dsValues.Tables[0]
}
Error:
[ScriptBlock] $scriptBlock = $(throw <<<< "The parameter -scriptBlock is required.")
Edit [Graimer]
When I have moved the curly braces like below
cUsing($sqlConnection = New-Object System.Data.SqlClient.SqlConnection){
....
....
Write-Host $dsValues.Tables[0]}
I am not getting any error but the output which I am getting is
$sqlConnection.ConnectionString = "Server=myserver; Database=master; Integrated Security= True"
$sqlConnection.Open()
$sqlCmd = New-Object System.Data.SqlClient.SqlCommand
$sqlCmd.CommandText = "Select query"
$sqlCmd.Connection = $sqlConnection
$dsValues = New-Object System.Data.DataSet
$daValues = New-Object System.Data.SqlClient.SqlDataAdapter($sqlCmd)
$daValues.Fill($dsValues)
Write-Host $dsValues.Tables[0]
EDIT [Ansgar Wiechers]
when I have changed the scriptblock line to
Function cUsing {
param (
[System.IDisposable] $inputObject = $(throw "The parameter -inputObject is required."),
[ScriptBlock] $scriptBlock = ${throw "The parameter -scriptBlock is required."}
)
I am not getting any error but I am getting the same output which I have showed in Edit above.

Answer 1

The problem with your code is that you don't provide the scriptblock as a parameter, but as a command on it's own. Commands in Powershell are on a single line. Your code runs the command with only the using parameter, and fails. THEN you declare a scriptblock.
You have two options here; escape the linebreak(BAD practice), or move the opening curly brace one line up so it is considered part of the cusing command. Like this:
cUsing($sqlConnection = New-Object System.Data.SqlClient.SqlConnection) {
$sqlConnection.ConnectionString = "Server=myserver; Database=master; Integrated Security= True"
...
..
.
}

Answer 2

A script block is defined via curly braces, not via $(). Like this:
[ScriptBlock]$scriptBlock = { throw "The parameter ..." }
$() is the operator for evaluating subexpressions.

Answer 3

Add-Type #"
using System;
public class Code : System.IDisposable
{
public bool IsDisposed { get; set; }
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!IsDisposed)
{
IsDisposed = true;
}
}
}
"#
function using-block {
param (
[System.IDisposable]$InputObject = $(throw "The parameter -inputObject is required."),
[ScriptBlock]$ScriptBlock = $(throw "The parameter -scriptBlock is required.")
)
try { &$ScriptBlock }
finally {
if ($InputObject) {
if ($InputObject.PSBase) {
$InputObject.PSBase.Dispose()
} else {
$InputObject.Dispose()
}
}
}
}
using-block($c = New-Object Code) {
$c.IsDisposed
}
$c.IsDisposed
Outputs:
False
True