c# barcode generator example 3: Doing Several Things at Once: Performance Enhancements with Threading in Objective-C

Printer gs1 datamatrix barcode in Objective-C 3: Doing Several Things at Once: Performance Enhancements with Threading

To eliminate the drudgery of coding a slew of identical conditional statements one after another, JavaScript provides you with four looping statements. Remember from earlier that those are while, do while, for, and for in. We will explore each of those in turn, beginning with the simple while loop. while loops are like an if condition that runs over and over until its expression returns false. Not surprisingly, from a syntax point of view, while and if statements appear similar: if (expression) path while (expression) path Just as JavaScript converts the value of an if condition s expression to a boolean if necessary, it does so for a while loop s expression, too. So to JavaScript, the game plan looks like this: while (Boolean(expression)) path The first time JavaScript runs a while statement, if the expression returns true or a value that converts to true, then the path runs. On the other hand, if the expression returns false or a value that converts to false (remember those are undefined, null, "", 0, or NaN), then the path does not run. That is to say, on its first iteration, a while loop is no different from an if condition. Now if the path ran on the first iteration, JavaScript has to decide whether to take another roundabout of the path. To do so, it simply reevaluates the while loop s expression. In the event that the expression again returns a truthy value, the path runs. But if the expression returns a falsy value, the path does not run, so JavaScript moves past the while loop and continues with the remainder of your script. Iterations of the while loop continue until its expression returns a falsy value. With this in mind, you want to ensure that eventually the expression does return a falsy value. Otherwise, the loop will never stop iterating. Such a mistake is aptly referred to as an infinite loop. Those freeze the browser until its long-running script limit, typically between 5 and 10 seconds, is reached. Essentially, we want to write an if condition but somewhere in the path make sure that expression will eventually return a falsy value. Typically, this is done by incrementing a loop variable, traditionally named i, j, or k, which you in turn compare to the number of roundabouts you want JavaScript to take. So, click Clear in both Firebug panels, and let s enter and run a simple while loop. I don t know about you, but a cup of tea brightens my mood. So, if I am feeling a little glum and want to rummage through the looseleaf teas in the pantry looking for Borpatra, my favorite Assam tea, I could do so with the following while loop. So, enter and run the following: var looseLeafTea = [ "Ghillidary", "Kenilworth", "Milima", "Keemun", "Boisahabi", "Manohari", "Borpatra", "Lukwah", "Khongea" ]; var mood = "glum"; var i = 0; while (i < looseLeafTea.length) { if (looseLeafTea[i] === "Borpatra") { mood = "cheery"; break;

using System; class Person { protected string firstName, lastName; // constructor method... public Person(string firstName, string lastName) { this.firstName = firstName; this.lastName = lastName; } // method... public void Greet() { Console.WriteLine("Hello " + firstName + " " + lastName + "!"); } } // Man derives from Person class... class Man : Person { // create a Man by calling base Person constructor... public Man(string fName, string lName) : base(fName, lName) {} // replace base Greet method with a new implementation... public new void Greet() { Console.WriteLine("Hello Mr. " + lastName + "!"); } } class Test { public static void Main() { Person p = new Person("Joe", "Bloggs"); p.Greet(); // displays "Hello Joe Bloggs!" Man m = new Man("Joe", "Bloggs"); m.Greet(); // displays "Hello Mr. Bloggs!" } }

Check that you have saved both the .h and .m files, then open Interface Builder by double-clicking MainMenu.xib. Since you are using the AppDelegate object as the Controller, there is no need to add one from the Library as you would have had to do if you had created a dedicated Controller in the Xcode Project Workspace. So let s continue on and build the user interface. First, make the window 480 pixels wide and 360 pixels high (Size Inspector tab). Uncheck the Close, Resize, and Minimize controls in the Attributes Inspector tab this is going to be a simple nonresizable window. Select the Library window and drag out a Color Well, a Vertical Slider, and a Text Field. For the Vertical Slider, set the Height value to 260 pixels, the Minimum Value to 0, the Maximum Value to 255 and the Current value to 128. Set the state to Continuous. Set the Text Field s Alignment to Centered, its width to 40 and leave the Height as 22. Now copy the Vertical Slider and Text Field controls three times (opt-drag is an easy way to do this). The fourth Slider should have a Maximum Value of 1.0 and a Current Value of 0.5. The user interface should look something like Figure 7 3.

SQL 2005 INSERT took UPDATE took DELETE took INSERT took UPDATE took DELETE took 1773 ms. 1356 ms. 826 ms. 40860 ms. 32073 ms. 30123 ms. SQL 2008 INSERT took UPDATE took DELETE took INSERT took UPDATE took DELETE took 700 ms. 1393 ms. 610 ms. 22873 ms. 35180 ms. 28690 ms.

Figure 10-9 shows a two-dimensional rectangular array. A three-dimensional array is a simple extension of a two-dimensional array.

Before starting on developing the user interface, it is a good idea to visit the Document window and check on the various objects that the assistant has created here. You will see that there are four new array controllers: one for the Journal Entry and one for each of the other entities. These are here because of the to-many relationships between the journalEntry entity and each of these entities. However, you will find that as you build more and more complex interfaces these controllers can be a little confusing as they are simply named for their entity. So, for example, every array controller that the assistant creates for the Consultant entity will be called Consultant Array Controller. So it is a good idea to adopt a naming convention that unambiguously names each controller. I tend to use a convention for windows, too. So in this case I gave the window the name wJournalEntry and I renamed the Journal Entry Array Controller to ac Journal Entry. For the other array controllers, I wanted to make the relationship clear in the name. I renamed Consultant Array Controller to ac Consultant for Journal Entry (since that relationship is what the controller is managing), and so on. See Figure 9 7.

Using dynamic dataset queries Another variation of data filtering is using dynamic queries, where a stored procedure or an expression determines what data will be fetched based on the user s identity. Let s consider a more complicated scenario than the one we discussed in the above section. This time we want to factor in the user s Windows group membership. For example, we want to allow members of the Sales Managers Windows group to be able to select any salesperson. However, we still want to allow members of the Sales Windows group to be able to see their sales data only. Determining the user s Windows group membership With a little bit of embedded custom code, implementing these requirements is straightforward. We could write a simple function to tell us whether the user is a member of a given Windows group. A possible implementation of such a function is the IsInRole function.

XElement newBook = new XElement("book", "LINQ in Action"); XElement firstBook = books.Element("book"); firstBook.AddAfterSelf(newBook);

XAML:

function GetServerInfoWork { param([string]$computername,[string]$logfile) $os = Get-WmiObject Win32_OperatingSystem -computer $computername $disk = Get-WmiObject Win32_LogicalDisk -filter "DeviceID='C:'" ` -computer $computername # use $logfile to get the value from the # -logfile parameter $obj = New-Object -TypeName PSObject

An object is created. The object is used. The object is deleted. Something that didn t know the object was deleted calls a method on that object.

and follow the setup directions. Interpreting the execution log data This SSIS package will assist you in setting up an automatic process to keep your log files in a new database called RSExecutionLog. Once you install and run the package and deploy the Execution Log Sample Reports report project, you will have some useful reports to analyze the execution log data. For example, the Report Execution Summary (figure 8.28) shows you the report activity and top requested reports per day. Glancing at the chart, you can easily see that the Report Server took the most hits on Tuesday during the requested week.

The Assert class has static methods and is located in the NUnit.Framework namespace. It s the bridge between your code and the NUnit framework, and its purpose is to declare that a specific assumption is supposed to exist. If the arguments that are passed into the Assert class turn out to be different than what we re asserting, NUnit will realize the test has failed and will alert us. We can optionally tell the Assert class what message to alert us with if the assertion fails. class has many methods, with the main one being which verifies a Boolean condition. But there are many other methods. The

Add the following Using statements to the CustomerService.cs file:

There may be other scopes, such as those for groups defined inside a region. Based on the current or containing scope rule we mentioned earlier, there are some valid and invalid reference combinations, as shown in table 5.2.