zxing barcode reader java example Using the this Keyword on the Main Timeline in Java

Creating Universal Product Code version A in Java Using the this Keyword on the Main Timeline

Using the this Keyword on the Main Timeline
Decoding UCC - 12 In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
Drawing UPC A In Java
Using Barcode printer for Java Control to generate, create UPC-A Supplement 5 image in Java applications.
If you use the this keyword on the Main Timeline, outside an event handler, this refers to the Main Timeline For example, the following code, when the movie plays, would give you a value of _level0, which is the same as _root
Scanning UPCA In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
Bar Code Maker In Java
Using Barcode drawer for Java Control to generate, create barcode image in Java applications.
trace(this); Using the this Keyword Inside a Movie Clip
Barcode Scanner In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
Generating GS1 - 12 In C#.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create UPC-A Supplement 5 image in .NET applications.
If you use the this keyword inside the Timeline of a movie clip, this refers to each instance of that movie clip For example, if you placed the following code inside a frame in a movie clip s Timeline, you would see _level0, a dot, and then the instance name of the movie clip
Generate UPC-A Supplement 2 In .NET
Using Barcode generation for ASP.NET Control to generate, create UPC Code image in ASP.NET applications.
UPCA Creator In .NET Framework
Using Barcode generation for .NET Control to generate, create UCC - 12 image in VS .NET applications.
trace(this); Using the this Keyword in an Event Handler
Drawing UPC Symbol In VB.NET
Using Barcode creator for .NET framework Control to generate, create Universal Product Code version A image in Visual Studio .NET applications.
UPC A Encoder In Java
Using Barcode generator for Java Control to generate, create UPCA image in Java applications.
There is one massive trap with understanding the this keyword When you write an event handler, or any type of function attached to an object, the this keyword refers to the object on which the function is being created For example, the code that follows shows an onRelease event handler for a movie clip called my_mc that traces the value of this
Encoding GS1 RSS In Java
Using Barcode printer for Java Control to generate, create GS1 DataBar Truncated image in Java applications.
Paint Code 39 Full ASCII In Java
Using Barcode printer for Java Control to generate, create Code 39 image in Java applications.
my_mconRelease = function():Void { trace(this); }
Uniform Symbology Specification Code 93 Printer In Java
Using Barcode maker for Java Control to generate, create Code 93 Full ASCII image in Java applications.
Data Matrix Drawer In Visual C#
Using Barcode printer for Visual Studio .NET Control to generate, create Data Matrix image in VS .NET applications.
Here, the value in the Output window will show the movie clip my_mc This is because the code inside the curly braces is connected to my_mc Remembering this will help you greatly in working with the this keyword
Paint GS1 - 12 In None
Using Barcode printer for Software Control to generate, create UPC A image in Software applications.
Bar Code Maker In Java
Using Barcode encoder for Android Control to generate, create barcode image in Android applications.
C H A P T E R
Decoding Barcode In Visual C#.NET
Using Barcode Control SDK for .NET Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
Paint Barcode In .NET Framework
Using Barcode creation for Reporting Service Control to generate, create barcode image in Reporting Service applications.
EXERCISE 2-14: Using the this Keyword
EAN / UCC - 13 Drawer In Visual C#.NET
Using Barcode encoder for .NET framework Control to generate, create GS1 - 13 image in .NET applications.
Read Code 3/9 In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
In this exercise, you will get practice using the this keyword to communicate to different movie clips You will also get practice using the this keyword in different contexts
1 Open the Flash file you used in the last exercise 2 On the Main Timeline, double-click parent_mc to enter its Timeline 3 Select the first keyframe of the actions layer, open the Actions panel, and
delete the code that you have previously written
4 Type the following code in the Actions panel:
this_x = 0;
5 Test the movie Notice the parent_mc movie clip s X position is at the left
edge of the Stage, as shown in the following illustration In this case, the this keyword represents parent_mc
The this keyword, when placed within a movie clip, represents each instance of that movie clip If you were to place many instances of mcParent on the Main Timeline, each instance would have an X position of zero when the movie is played Code within a movie clip affects all instances of that movie clip because it is a change made directly on a symbol via Symbol Editing mode, rather than to one particular instance
ActionScript 20 Essentials
NINTENDO
FLASH
GAME
CREATOR S
GUIDE
6 Return to the Main Timeline by clicking Scene 1 in the Timeline 7 On the Main Timeline, select the first keyframe of the actions layer and
open the Actions panel
8 In the Actions panel, type the following code:
thischild2_mc_y = 0;
9 Test the movie You should then see the child2_mc movie clip at a Y
position of zero, as shown next This is because the this keyword, in this instance, refers to the Main Timeline, and the child2_mc movie clip is on the Main Timeline This code would look the same if the this keyword were replaced by _root, because here, both represent the Main Timeline
10 On the Stage of the Main Timeline, double-click the parent_mc movie clip
to enter its Timeline
11 Inside the Timeline of mcParent, select the first keyframe of the actions
layer and open the Actions panel
12 In the Actions panel, beneath the code you already wrote, create an
onRelease event handler for the child_mc movie clip by typing the following code:
child_mconRelease = function():Void { }
C H A P T E R
13 Inside the curly braces of the event handler, type this_y = 0; Your code
should match the code shown:
child_mconRelease = function():Void { this_y = 0; }
14 Before you test the movie, predict what will happen What does the this
keyword mean here
15 Test the movie Click the child_mc movie clip inside the parent_mc movie
clip Notice that the child movie clip moves to a Y position of zero, as in the following illustration, showing that in the code you just wrote, the this keyword represents child_mc
16 Examine all the code you wrote in this exercise Notice that the this
keyword represents three different objects Make sure you understand which object the this keyword represents in each context and why
17 Save the file, or keep it open for the next exercise
Using the Insert Target Path Button
If the syntax to communicate to a particular movie clip ever seems confusing, you can use the Insert Target Path button in the Actions panel to have Flash write the path for you The Insert Target Path button will give you the path to any object with an instance name in your Flash file This is a very quick and effective way to communicate from one object to another, without requiring you to remember each object s instance name
Copyright © OnBarcode.com . All rights reserved.