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ASP.NET Web PDF Document Viewer/Editor Control LibraryBefore you start using the plugin, you need to know how Qt handles plugins They are loaded by the QApplication (actually by its superclass QCoreApplication) object, so you must make sure to have an instance of QApplication available when you use a plugin After you have a QApplication object, you can query the QImageReader and QImageWriter classes for a list of supported formats by using the static supportedImageFormats method The reader returns the readable image formats, while the writer returns the writeable image formats The returned value is a QList of QByteArray objects, which is a list of all the available keys returned from the different QImageIOPlugin objects Listing 11-12 shows a small foreach loop that queries for all readable image formats and prints them to the debugging console All formats that can be read can usually also be written but you can never assume this Listing 11-12. creare barcode con excel 2013, generate barcode in excel 2003, excel 2010 microsoft barcode control, free barcode generator for excel 2013, barcode in excel 2010 freeware, barcode font excel 2010 free, barcode font excel 2010 download, barcode plugin excel 2007, barcode in excel, barcode in excel 2007 free,When you come to use ArgumentNullException (which you throw when you are erroneously passed a null argument) you ll find that the error message and parameter arguments are swapped around in the constructor. This irritating inconsistency has been with us since .NET 1.0, and too much code depends on it to fix it now. static void Main(string[] args) { Turtle arthurTheTurtle = new Turtle { PlatformWidth = 0.0, PlatformHeight = 10.0, MotorSpeed = 5.0 }; ShowPosition(arthurTheTurtle); try { To create this client, start a new Visual Studio 2005 web site, and edit the default WebForm1.aspx content to match Listing 1-1. Listing 1-1. Creating Your First Ajax Application <%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="Atlas1_1.WebForm1" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <HTML> <HEAD> <title>WebForm1</title> <script language="javascript"> var xmlHttp; function createXMLHttpRequest() { if (window.ActiveXObject) { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } else if (window.XMLHttpRequest) { xmlHttp = new XMLHttpRequest(); } } arthurTheTurtle.RunFor(0.0); // ... } catch (InvalidOperationException e) { Console.WriteLine("Error running turtle:"); Console.WriteLine(e.Message); } catch (Exception e1) { // Loop through the inner exceptions, printing their messages Exception current = e1; while (current != null) Asking Qt for the image formats that can be read QApplication app( argc, argv ); foreach( QByteArray ba, QImageReader::supportedImageFormats () ) qDebug() << ba; When reading, Qt usually determines the file format by querying the plugin s capabilities methods This generates a call to the different canRead methods that determine whether the specific plugin can handle the given file (The application just needs to specify the file name; Qt does the rest of the work) As shown in Listing 11-13, the resulting QImage is a null image if the loading fails If you use the load method of QImage, you can get the return value from it The method returns true if the image is loaded; it returns false if it fails Listing 11-13 Reading an ASCII art image QImage input( "inputti" ); if( inputisNull() ) qDebug() << "Failed to load. { } } } finally { Console.WriteLine("Waiting in the finally block"); Console.ReadKey(); } "; The opposite of reading saving is slightly more complex Because there is no file prefix to look for, you need to specify the file format when calling save (see Listing 11-14) In the listing, a png image is read from disk If the read is successful, the image is saved again as a ti image The save call returns a bool value, which indicates whether the operation was successful The value true means that it worked.. Console.WriteLine(current.Message); current = current.InnerException; If we compile and run, we ll see the following output: Arthur is at (0,0) and is pointing at angle 0.00 radians. Must provide a duration greater than 0 Parameter name: duration Waiting in the finally block function updateTotal() { frm = document.forms[0]; url="WebForm2.aspx A=" + frm.elements['A'].value + "&B=" + frm.elements['B'].value; xmlHttp.open("GET",url,true); xmlHttp.onreadystatechange=doUpdate; xmlHttp.send(); return false; } function doUpdate() { if (xmlHttp.readyState==4) { document.forms[0].elements['TOT'].value=xmlHttp.responseText; } } </script> </HEAD> <body onload="createXMLHttpRequest();"> <form> <TABLE height="143" cellSpacing="0" cellPadding="0" width="300" border="0" > <TR vAlign="top"> <TD height="32">First Value</TD> <TD><INPUT type="text" id="A" value="0" onkeyup="updateTotal();"></TD> </TR> <TR vAlign="top"> <TD height="32">Second Value</TD> <TD><INPUT type="text" id="B" value="0" onkeyup="updateTotal();"></TD> </TR> <TR vAlign="top"> <TD height="23">Returned Total</TD> <TD><INPUT type="text" id="TOT" value="0"></TD> </TR> </TABLE> </form> </body> </HTML> When the web page loads, the createXMLHttpRequest function is called (from onload= in the body tag) to initialize the object. After that, whenever a key is pressed in the A or B text boxes, the updateTOT function is called (by trapping the onkeyup event). This function then takes the values of A and B from their form elements and uses them to build the URL to WebForm2.aspx, which will look something like WebForm2.aspx A=8&B=3. It then calls the open method on XMLHttpRequest, passing it this URL and indicating that this
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