generate barcode c# NOTE in C#

Creating QR in C# NOTE

NOTE
Painting QR Code In Visual C#
Using Barcode drawer for .NET framework Control to generate, create QR Code ISO/IEC18004 image in .NET applications.
www.OnBarcode.com
QR Code 2d Barcode Reader In C#.NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
The following sections contain quite a bit of code. If you don t want to type this code, you can open the completed Weather Tracker project in the companion content and copy the sections of code as needed.
Encoding Barcode In Visual C#
Using Barcode generator for VS .NET Control to generate, create bar code image in .NET applications.
www.OnBarcode.com
Scanning Bar Code In Visual C#
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
First, talking to a Web service can be a long process. A long process typically means only a few seconds (perhaps up to 30 seconds), but you can t leave the user with a blocked UI while your application is retrieving information. You therefore need a way of saying to your application: Go get this information and let me know when you have it. This programming technique is called multithreaded programming with call backs. In .NET Framework 2.0, this type of programming is simplified by creating a new class called the BackgroundWorker class. As its name implies, it works in the background on a task; what s not implied is that it will let you know when it has completed the task.
Encoding Quick Response Code In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create QR Code 2d barcode image in ASP.NET applications.
www.OnBarcode.com
Drawing QR Code JIS X 0510 In Visual Studio .NET
Using Barcode encoder for VS .NET Control to generate, create Quick Response Code image in VS .NET applications.
www.OnBarcode.com
TO PERFORM A TASK IN THE BACKGROUND 1 Open the Main form in design view. 2 onto your form. It doesn t have a design time portion, so it will be added to the component tray.
QR Code ISO/IEC18004 Generator In VB.NET
Using Barcode encoder for VS .NET Control to generate, create Denso QR Bar Code image in .NET applications.
www.OnBarcode.com
Encoding Data Matrix 2d Barcode In C#.NET
Using Barcode generator for VS .NET Control to generate, create Data Matrix image in .NET framework applications.
www.OnBarcode.com
Rename it backgroundCurrentWorker. At the top of the Properties window for backgroundCurrentWorker, click the events icon (yellow lightGo to the Toolbox. In the Components section, select the BackgroundWorker control and drag it
1D Barcode Creation In C#.NET
Using Barcode generator for VS .NET Control to generate, create 1D Barcode image in .NET applications.
www.OnBarcode.com
Bar Code Maker In Visual C#
Using Barcode printer for Visual Studio .NET Control to generate, create barcode image in .NET framework applications.
www.OnBarcode.com
3 ning) and then double-click the DoWork event.
ANSI/AIM Code 39 Generation In C#
Using Barcode printer for .NET framework Control to generate, create Code 39 Full ASCII image in .NET applications.
www.OnBarcode.com
Encoding International Standard Book Number In C#.NET
Using Barcode printer for .NET framework Control to generate, create ISBN - 10 image in .NET applications.
www.OnBarcode.com
4 At the top of Main.cs, add the following using statements to the existing using statements.
Barcode Printer In Java
Using Barcode maker for BIRT Control to generate, create barcode image in Eclipse BIRT applications.
www.OnBarcode.com
Bar Code Maker In None
Using Barcode printer for Office Word Control to generate, create bar code image in Word applications.
www.OnBarcode.com
1 using Weather_Tracker.Properties; 2 using Weather_Tracker.WeatherWebService;
Barcode Recognizer In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Drawing Barcode In VB.NET
Using Barcode maker for .NET framework Control to generate, create barcode image in VS .NET applications.
www.OnBarcode.com
5 Add the following code to the backgroundCurrentWorker_DoWork event handler.
Code128 Scanner In .NET Framework
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Encode Bar Code In VS .NET
Using Barcode generator for ASP.NET Control to generate, create bar code image in ASP.NET applications.
www.OnBarcode.com
3 private void backgroundCurrentWorker_DoWork(object sender, DoWorkEventArgs e) 4 { 5 6 7 8 9 10 11 12 } // This method will execute in the background thread created by the // BackgroundWorker component int desiredZipCode = (int)e.Argument; Service weatherService = new Service(); e.Result = weatherService.GetWeatherInfo2( Settings.Default.Username, Settings.Default.Password,desiredZipCode);
EAN13 Encoder In None
Using Barcode generation for Font Control to generate, create GTIN - 13 image in Font applications.
www.OnBarcode.com
Decode Data Matrix In Visual Studio .NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Microsoft Visual C# 2005 Express Edition: Build a Program Now!
The DoWork event handler is where the call to the weather Web service is performed. You will start by calling the GetWeatherInfo2 method exposed by the Web service. When you invoke the GetWeatherInfo2 method, it runs in a separate context so that it doesn t block the application UI. Otherwise, the application might appear to hang. The GetWeatherInfo2 method takes three parameters (username, password, ZIP code) and returns a WeatherInfo result. How do you know what parameters you need and the return value You can look at the WSDL (pronounced WISDLE) file to understand. Also, when you added the weather Web service, Visual Studio generates the appropriate IntelliSense.
6 Add the following startBackgroundTaskCurrentDay method.
13 private void startBackgroundTaskCurrentDay() 14 { 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 } } } catch (Exception) { MessageBox.Show( Fatal Error! , Fatal error starting background task ); throw; } // Normally an exception handling class or logging would be used, // but we ll just use a message box. catch (FormatException) { MessageBox.Show( Invalid conversion from string to int , Parse Zip Code Exception ); throw; } try { // Execute the background task only if it s not already working if (!backgroundCurrentWorker.IsBusy) { this.UseWaitCursor = true; this.backgroundCurrentWorker.RunWorkerAsync( int.Parse(currentZipCode));
9: Build Your Own Weather Tracker Application Now!
The startBackgroundTaskCurrentDay method starts the BackgroundWorker. The first thing you need to do is verify whether the BackgroundWorker is already busy with a previous call; if you don t do this, you ll end up with an InvalidOperationException. Simply verifying whether the BackgroundWorker is busy ensures that you won t get that exception when calling the RunWorkerAsync method. In fact, this is the only exception that this method can raise. A quick look at the documentation can confirm this. Executing the RunWorkerAsync method is submitting a request to start an operation asynchronously, which raises the DoWork event. An event handler with the following name format is invoked: <your backgroundworker variable>_DoWork. In your case, the backgroundCurrentWorker_DoWork method is executed when the DoWork event is raised.
7 Switch to Design view and select backgroundCurrentWorker in the component tray. 8 In the events list in the Properties window, double-click the RunWorkerCompleted event. 9 Add the following code to the BackgroundCurrentWorker_RunWorkerCompleted event handler.
40 private void backgroundCurrentWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 41 { 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 } else if ((e.Error.Message.IndexOf( 503 ) > 0)) { MessageBox.Show( Weather Web service is unavailable, retry later!\n + Retry later using the Refresh Weather Info menu. , Weather Web service unavailable ); if ((e.Error == null)) { this.UseWaitCursor = false; WeatherInfo weatherInfo; weatherInfo = (WeatherInfo)e.Result; weatherInfoBindingSource.DataSource = weatherInfo; pbCurrentTemp.Load(@ .\Images\ + weatherInfo.IconIndex.ToString() + .gif ); // If web service returned weather info, then // update notify icon currentTemperature = this.ExtractTemperature(); this.CreateIcon((int)Math.Round(currentTemperature));
Microsoft Visual C# 2005 Express Edition: Build a Program Now!
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 }
} else if ((e.Error.Message.IndexOf( timed out ) > 0)) { MessageBox.Show( Unable to retrieve the data in the time allowed\n + Retry later using the Refresh Weather Info menu. , Weather Web service Timeout ); } else { MessageBox.Show( Problem with Weather Web service! Error message:\n + e.Error.Message + \nRetry Later! , Weather Web service problem ); }
If the Web service was available and your parameters were good, the method you invoked is then working in a different context and on its own. When it is finished with its business, you will be notified that the method has completed because a RunWorkerCompleted event will be raised.
To retrieve the results, you must have an event handler with the following name: <your backgroundworker variable>_RunWorkerCompleted. In this method, you have a parameter of type RunWorkerCompletedEventArgs that contains everything you need to obtain the results. If an exception was raised in the DoWork event handler, you ll be able to retrieve it by checking the Error property, which is of type Exception. If there is no error, then you must retrieve the results yourself. Remember that the Results property will give you an element of type Object, which by itself will not help you. You need to assign it a variable with the same type that the Web service method used to spit out the results.
9: Build Your Own Weather Tracker Application Now!
You may be wondering: What is the link between the index and the filename, and who is creating that link This is a convention used by many weather providers on the Internet; therefore, this is something that will work with many services if you want to add some later.
In your case, if you look into the method signature for GetWeatherInfo2, WeatherInfo is the type of results it is producing. Therefore, you need to declare a variable of that type. If you recall, when you dragged the WeatherInfo dataset onto the designer surface, you automatically created databound controls for all of those fields. Thus, you simply need to assign that WeatherInfo variable as the DataSource for your BindingSource, and you will have a link between what s coming from the Web service and the controls on your form. Now, you also have a picture box on the designer surface that will serve to display an icon portraying the current forecast. The info is returned to you as an index: the iconIndex property. You need to load an image file from your hard drive into the picture box you dragged onto the designer surface using the index as the filename. What happens next is the creation of the icon that will appear in the notification area representing the current temperature.
Copyright © OnBarcode.com . All rights reserved.