barcode vb.net code PS (1) > pwd Path ---C:\Documents and Settings\brucepay in C#.NET

Drawer Code39 in C#.NET PS (1) > pwd Path ---C:\Documents and Settings\brucepay

PS (1) > pwd Path ---C:\Documents and Settings\brucepay
Drawing USS Code 39 In C#.NET
Using Barcode encoder for .NET framework Control to generate, create Code-39 image in .NET framework applications.
www.OnBarcode.com
Scanning Code-39 In C#
Using Barcode reader for VS .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Now we ll use the CurrentDirectory static method on the .NET class System.Environment to check the process working directory.
EAN13 Generator In Visual C#
Using Barcode creation for VS .NET Control to generate, create UPC - 13 image in VS .NET applications.
www.OnBarcode.com
Denso QR Bar Code Encoder In C#.NET
Using Barcode generator for VS .NET Control to generate, create QR Code ISO/IEC18004 image in .NET applications.
www.OnBarcode.com
PS (2) > [System.Environment]::CurrentDirectory C:\Documents and Settings\brucepay
Matrix Maker In Visual C#.NET
Using Barcode generation for .NET Control to generate, create Matrix 2D Barcode image in VS .NET applications.
www.OnBarcode.com
ECC200 Creation In Visual C#
Using Barcode generation for .NET framework Control to generate, create DataMatrix image in .NET applications.
www.OnBarcode.com
USING .NET FROM POWERSHELL
Encode Barcode In C#.NET
Using Barcode generation for .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
Creating ANSI/AIM ITF 25 In Visual C#.NET
Using Barcode maker for .NET Control to generate, create USS ITF 2/5 image in VS .NET applications.
www.OnBarcode.com
So far they match. Now use the PowerShell cd command to set the PowerShell current working directory to the root of the C: drive, and then verify the path with pwd.
Code 3 Of 9 Drawer In Visual Basic .NET
Using Barcode encoder for .NET framework Control to generate, create Code 3 of 9 image in Visual Studio .NET applications.
www.OnBarcode.com
Recognizing Code39 In Visual C#
Using Barcode scanner for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
PS (3) > cd c:\ PS (4) > pwd Path ---C:\
Data Matrix 2d Barcode Creation In .NET
Using Barcode maker for ASP.NET Control to generate, create Data Matrix 2d barcode image in ASP.NET applications.
www.OnBarcode.com
Encode Barcode In Java
Using Barcode generation for BIRT Control to generate, create Barcode image in Eclipse BIRT applications.
www.OnBarcode.com
Fine everything is as we would expect. But now we check the process current working directory.
GTIN - 13 Drawer In None
Using Barcode printer for Font Control to generate, create GTIN - 13 image in Font applications.
www.OnBarcode.com
Encoding Code 39 Full ASCII In Java
Using Barcode printer for Java Control to generate, create Code39 image in Java applications.
www.OnBarcode.com
PS (5) > [Environment]::CurrentDirectory C:\Documents and Settings\brucepay
Print Barcode In Objective-C
Using Barcode drawer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Generate Barcode In VS .NET
Using Barcode maker for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
It still points to the original location. Clearly, using cd in PowerShell doesn t affect the process current working directory. Now let s look at the another reason for always using full path names. Let s cd into the root of the registry.
Generating PDF-417 2d Barcode In Java
Using Barcode drawer for BIRT Control to generate, create PDF-417 2d barcode image in Eclipse BIRT applications.
www.OnBarcode.com
QR Code 2d Barcode Maker In Java
Using Barcode encoder for Eclipse BIRT Control to generate, create Denso QR Bar Code image in BIRT reports applications.
www.OnBarcode.com
PS (6) > cd hklm:\ PS (7) > pwd Path ---HKLM:\
Paint Code-39 In Visual Studio .NET
Using Barcode printer for Reporting Service Control to generate, create Code-39 image in Reporting Service applications.
www.OnBarcode.com
Painting Matrix 2D Barcode In .NET
Using Barcode generator for .NET framework Control to generate, create 2D Barcode image in .NET framework applications.
www.OnBarcode.com
The PowerShell current directory is now in the registry. This is something that the process current directory just can t handle. It can only ever point to some place in the filesystem. Clearly, the PowerShell and process notions of current directory have to be different.
AUTHOR S NOTE
There can be more than one PowerShell session (called a runspace) in a process at the same time. Each of these runspaces can have its own current directory. The process only has a single current directory value. This is covered in the PowerShell SDK documents and in Jim Truher s book Windows PowerShell in Practice, also from Manning Publications.
Let s reiterate why this behavior is a problem when using .NET methods: any .NET method that is passed a relative pathname will use the process current working directory to resolve the path instead of the PowerShell current working directory. Let s check this out. We ll cd back into the root of the C: drive again and create a text file hello.txt .
PS (8) > cd c:\ PS (9) > "Hello there" > hello.txt
CHAPTER 1 1
GETTING FANCY .NET AND WINFORMS
We can get this file from PowerShell using Get-Content and specifying a relative path:
PS (10) > get-content Hello there hello.txt
It works. But now when we try using a .NET method and specify a relative path:
PS (11) > [io.file]::ReadAllText("hello.txt") Exception calling "ReadAllText" with "1" argument(s): "Could not find file 'C:\Documents and Settings\brucepay\hello.txt'." At line:1 char:23 + [io.file]::ReadAllText( <<<< "hello.txt")
it fails. This is because it s using the process current directory to resolve the relative path, and that s still pointing to the directory where PowerShell was started.
PS (12) > [environment]::currentdirectory C:\Documents and Settings\brucepay
The PowerShell environment includes a cmdlet Resolve-Path, which is intended to make this scenario easy to work around. When the output of this command is converted into a string, it will be the full provider path to the target object in this case the file. Let s try this:
PS (13) > [io.file]::ReadAllText((resolve-path "hello.txt")) Hello there
There is another, even easier way to do this, although it is not strictly speaking per the guidelines. Instead of Resolve-Path, we can use the $PWD shell variable along with string expansion to prefix the path.
PS (13) > [io.file]::ReadAllText("$pwd\hello.txt") Hello there
Not only is this easier, it also has the advantage that it will work to produce paths that don t exist yet. If you re creating a file, Resolve-Path will fail because it can only resolve existing paths. With the string expansion approach, this problem doesn t exist. String expansion doesn t know anything about paths it s just giving us a new string. This is an important rule to keep in mind. If you look at the examples in chapter 10 where we were using the .NET XML APIs to process files, we always made sure to pass in absolute paths. If we are consistent and always use absolute file paths with methods that take paths, there won t be any problems. (Though it s usually easiest to use the Get-Content cmdlet instead. If we do, everything will work and we won t have to remember this extra step or close the handle when we re done with it.) Working with generic types, the next topic, has less to do with prior expectations and more to do with features that were cut from version 1.0 of PowerShell.
Copyright © OnBarcode.com . All rights reserved.