Visual studio 2010 part 37 potx

To get started, create a new Console project and add a Class file with the following method to the project, which simulates adding a new customer: C#: using System; class Customer {

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Writing Macros

When the productivity features that ship with VS and custom snippets don’t give you

enough power, the next step is to consider creating a macro, which is a repeatable set of

actions that you can record and re-run multiple times An example of when a macro is useful is whenever you find yourself continuously repeating the same set of actions in VS This section will show you how to create and run a macro that uses VS features to create a customized block of code for validating strings

Recording a Macro

When creating business objects, it’s common to validate input parameters to ensure they are valid One such validation is enforcing that calling code pass a required parameter The example in this section shows you how to write a macro for validating that a string-type parameter is not null, empty, or white space (such as a space or tab) To get started, create a new Console project and add a Class file with the following method to the project, which simulates adding a new customer:

C#:

using System;

class Customer

{

public int AddNewCustomer(string firstName, string lastName) {

int newCustID = 0;

// Logic to add customer

return newCustID;

}

VB:

Public Class Customer

Function AddNewCustomer(

ByVal firstName As String,

ByVal lastName As String) As Integer

Dim newCustID As Integer = 0

' Logic to add customer

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Return newCustID

End Function

End Class

The point of interest in the AddNewCustomer method is the firstName and lastName

parameters Whenever working with data, you’ll usually want to ensure that input data is

legal When user input is being processed, it’s common to get bad information, even if you have good input validation in your user interface code For example, the following code

calls the preceding AddNewCustomer method, passing in bad data as arguments:

C#:

class Program

{

static void Main()

{

string firstName = "Joe";

string lastName = null;

Customer cust = new Customer();

cust.AddNewCustomer(firstName, lastName);

}

VB:

Module Module1

Sub Main()

Dim firstName As String = "Joe"

Dim lastName As String = Nothing

Dim cust As New Customer

cust.AddNewCustomer(firstName, lastName)

End Sub

End Module

In the preceding example, firstName is okay because it has a good name in it

However, notice that lastName is set to null (Nothing in VB) This would cause

a NullReferenceException if AddNewCustomer tried to call a string operation on

the parameter, the code that AddNewCustomer calls could potentially throw a

NullReferenceException, or (assuming that null is considered invalid in this case) you

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could end up saving bad data Since AddNewCustomer doesn’t have an implementation,

this is all speculation, but this outlines a few of the many problems that can occur if you allow your business objects to accept data that is bad for your program

The macro demonstrated in this section will show how to check a string parameter

for null, empty, or white space and throw an ArgumentNullException This will prevent

callers from passing bad data and give them a meaningful message To create a macro, you will need to locate the position in the code where the macro starts (if applicable), start recording, perform VS actions, and stop recording It’s somewhat like using a video recorder where you have to find a TV show, start the recording, allow the show to play, and then stop recording Perform the following steps to create the parameter validation macro:

1. Click the firstName parameter of the AddNewCustomer method so that the cursor is inside of the firstName parameter identifier This is important because we need the

parameter name in the code

2 Start the macro recorder by selecting Tools | Macros | Record TemporaryMacro or press CTRL-SHIFT-R

3 For C#, press CTRL-LEFT ARROW, CTRL-SHIFT-RIGHT ARROW, and CTRL-C For VB, press CTRL-LEFT ARROW, CTRL-SHIFT-RIGHT ARROW, SHIFT-LEFT ARROW, and CTRL-C This copies the parameter name

4.For C#, press CTRL-F to bring up the Find And Replace window, type { into Find What,

click Find Next, Close the Find And Replace window, press END, and press ENTER For

VB, press END and press ENTER This positions the cursor to begin entering code

5. Type if and press TAB twice (the if snippet), type string.IsNullOrWhiteSpace( into the

condition, press CTRL-V to paste the parameter name as the argument, and type ) For

C#, press ENTER For VB, press DOWN ARROW The cursor moves to the body of the if statement (as you would expect with the if snippet) This sets up the validation check for the parameter, seeing if it is null (Nothing in VB), an empty string, or some white

space character such as space or tab

6.Type throw new ArgumentNullException(", press CTRL-V to paste the parameter

name, type ", ", press CTRL-V to paste the parameter name, type a space, and type value

is not valid.") For C#, add a semicolon, ;, to the end of the line This is the action to

perform when the value is not valid, throwing an exception to let the caller know that the value is not good

7 Press DOWN ARROW and press ENTER This positions the cursor after the code, which might be convenient if you want to continue typing from this point

8 Select Tools | Macros | Stop Recording TemporaryMacro or press CTRL-SHIFT-R to stop recording

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You’ve now recorded a macro To check the preceding steps against what you’ve

produced, here’s a revised AddNewCustomer method, showing what the results should

look like:

C#:

using System;

class Customer

{

public int AddNewCustomer(string firstName, string lastName)

{

if (string.IsNullOrWhiteSpace(firstName))

{

throw new ArgumentNullException(

"firstName",

"firstName value is not valid.");

}

int newCustID = 0;

return newCustID;

}

VB:

Public Class Customer

Function AddNewCustomer(

ByVal firstName As String,

ByVal lastName As String) As Integer

If String.IsNullOrWhiteSpace(firstName) Then

Throw New ArgumentNullException(

"firstName",

"firstName value is not valid.")

End If

Dim newCustID As Integer = 0

' Logic to add customer

Return newCustID

End Function

End Class

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In the preceding code, I’ve moved the ArgumentNullException arguments to separate

lines to fit the book’s line length, but this is what you should see Next, you can test

the macro by running it Click the lastName parameter and select Tools | Macros | Run

TemporaryMacro or press CTRL-SHIFT-P That will produce the following code:

public int AddNewCustomer(string firstName, string lastName)

{

if (string.IsNullOrWhiteSpace(lastName))

{

throw new ArgumentException("lastName", "lastName value is not valid.");

}

if (string.IsNullOrWhiteSpace(firstName))

{

throw new ArgumentException("firstName", "firstName value is not valid.");

}

int newCustID = 0;

return newCustID;

}

Now, you can run this macro on any of the string parameters of methods in your class and quickly add validation support The only problem at the present time is that the macro is overwritten as soon as you begin recording a new macro and the macro is gone if you close VS The next section addresses this problem by showing you how to save the macro

Saving a Macro

You can save macros to be reused in later sessions To save the macro, select Tools | Macros | Save TemporaryMacro VS will save TemporaryMacro and open the Macro Explorer window, shown in Figure 12-8

VS uses TemporaryMacro as the name of whatever macro it will record Therefore, you must rename the macro if you want to keep it because the next recording will

overwrite this macro Rename the file macro to ValidateStringParameter by

right-clicking TemporaryMacro in Macro Explorer, showing the context menu, and selecting Rename

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In the Macro Explorer, you can add new Macro Projects, which are containers for

holding macro modules, by right-clicking Macros and selecting New Macro Project If

someone shares their Macro Project with you, right-click Macros and select Load Macro

Project to find the project in the file system and load it Macro modules hold macros, and

you can right-click any macro project; such as MyMacros or Samples in Figure 12-8, and

select New Module to add new macro modules You can find all of these commands on

the Tools | Macros menu too

To run an existing macro, double-click the macro in Macro Explorer

To change a macro, you can either re-record or edit an existing macro The next

section explains how to edit a macro

Editing Macros

Macros are editable, allowing you to modify previously recorded macros or create a

brand new macro To edit a macro, right-click the macro in Macro Explorer and select

Edit You’ll see the Macro editor, shown in Figure 12-9, which contains the code for the

ValidateStringParameter macro created in the preceding section

In Figure 12-9, you can see that the editor opens the macro in a code editing window

The language is VB, so if the language you normally program with is C#, you might want to review the VB portions of Chapters 2 through 4 as a refresher The features of Macro editor

are very similar to the normal VS IDE, except that now you must work with Macro Projects

and Modules Listing 12-3 shows the macro code from Figure 12-9 In Listing 12-3, both the C# and VB macros are written in VB However, the C# code is for a macro that works on C# code and the VB code is for a macro that works on VB code

Figure 12-8 The Macro Explorer window

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Listing 12-3 Code for the ValidateStringParameter macro

C#:

Option Strict Off

Option Explicit Off

Imports System

Imports EnvDTE

Imports EnvDTE80

Imports EnvDTE90

Imports EnvDTE90a

Imports EnvDTE100

Imports System.Diagnostics

Public Module RecordingModule

Sub ValidateStringParameter()

DTE.ActiveDocument.Selection.WordLeft() DTE.ActiveDocument.Selection.WordRight(True) DTE.ActiveDocument.Selection.Copy()

DTE.ExecuteCommand("Edit.Find")

Figure 12-9 The Macro editor

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DTE.Windows.Item("Customer.cs").Activate()

DTE.Windows.Item("{CF2DDC32-8CAD-11D2-9302-005345000000}")

.Activate() 'Find and Replace

DTE.Find.FindWhat = "{"

DTE.Find.Target =

vsFindTarget.vsFindTargetCurrentDocument

DTE.Find.MatchCase = False

DTE.Find.MatchWholeWord = False

DTE.Find.Backwards = False

DTE.Find.MatchInHiddenText = False

DTE.Find.PatternSyntax = vsFindPatternSyntax

.vsFindPatternSyntaxLiteral

DTE.Find.Action = vsFindAction.vsFindActionFind

If (DTE.Find.Execute() =

vsFindResult.vsFindResultNotFound) Then

Throw New System.Exception("vsFindResultNotFound")

End If

DTE.Windows.Item(

"{CF2DDC32-8CAD-11D2-9302-005345000000}").Close()

DTE.ActiveDocument.Selection.EndOfLine()

DTE.ActiveDocument.Selection.NewLine()

DTE.ActiveDocument.Selection.Text = "if"

DTE.ExecuteCommand("Edit.InsertTab")

DTE.ActiveDocument.Selection.Text =

"string.IsNullOrWhiteSpace("

DTE.ActiveDocument.Selection.Paste()

DTE.ActiveDocument.Selection.Text = ")"

DTE.ExecuteCommand("Edit.BreakLine")

"throw new ArgumentNullException("""

DTE.ActiveDocument.Selection.Text = """, """

" value is not valid."");"

DTE.ActiveDocument.Selection.LineDown()

End Sub

End Module

VB:

Option Strict Off

Option Explicit Off

Imports System

Imports EnvDTE

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Imports EnvDTE80

Imports EnvDTE90

Imports EnvDTE90a

Imports EnvDTE100

Imports System.Diagnostics

Public Module RecordingModule

Sub ValidateStringParameter()

DTE.ActiveDocument.Selection.WordLeft()

DTE.ActiveDocument.Selection.WordRight(True)

DTE.ActiveDocument.Selection.CharLeft(True)

DTE.ActiveDocument.Selection.Copy()

DTE.ActiveDocument.Selection.EndOfLine()

DTE.ActiveDocument.Selection.Text = "if"

DTE.ExecuteCommand("Edit.InsertTab")

DTE.ActiveDocument.Selection.Text = "string.IsNullOrEmpty(" DTE.ActiveDocument.Selection.Paste()

DTE.ActiveDocument.Selection.Text = ")"

"throw new ArgumentNullException("""

DTE.ActiveDocument.Selection.Text = """, """

" value is not valid."")"

End Sub

End Module

In Listing 12-3, all of the namespaces that begin with EnvDTE have code that allows you to manipulate the VS environment The macro itself is a Sub within a Module.

Each of the statements corresponds to the steps used to create the macro in the preceding section For example, the Find And Replace window has several options, which this macro populates, regardless of whether they contribute toward the purpose of the macro

Opening a macro in the editor can be very useful if you want to make a quick change, without needing to re-record the entire macro For example, what if you missed a keystroke

or misspelled something? You can just edit the code, save the file, close the Macro editor, and then re-run the macro In fact, there is a problem with the macro for C#; it will only

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work on the file you ran it in This problem doesn’t occur in the macro for VB I’ll show

you how to fix this problem, but let’s open the macro editor first

You can open the Macro editor through VS by selecting Tools | Macros | Macros IDE,

start a new project, add a module to the project, and add a Sub to the Module as a new

macro Then code the macro by typing DTE and using Intellisense to find various parts

of the IDE The cryptic parameter to Windows.Item,

{CF2DDC32-8CAD-11D2-9302-005345000000}, for the Find And Replace window is called a Globally Unique Identifier

(GUID) A GUID is often used as a special identifier for software components and is the

method used in VS to uniquely identify tools So,

DTE.Windows.Item("{CF2DDC32-8CAD-11D2-9302-005345000000}").Activate() is a way to reference and open the Find

And Replace window

There is a problem with the macro for C# in Listing 12-3, because it will only work in

the Customer.cs file in VS The VB code below is provided for your convenience, but this

problem only occurs with the macro written for C# code; the VB macro works fine on the

VB code below If you created a new class named Product in a file named Product.cs and

added an AddNewProduct method like the following, the macro will try to open and write

into the Customer.cs file, which is not the result you want:

C#:

using System;

namespace ConsoleApplication1

{

class Product

{

public int AddNewProduct(string productName)

{

int newProdID = 0;

// Logic to add product

return newProdID;

}

VB (doesn’t have problem that occurs in C# code):

Public Class Product

Function AddNewProduct(ByVal productName As String) As Integer

Dim newProdID As Integer = 0

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