generate pdf417 barcode c# The BindingSourceRefresh Control in Visual C#

Making PDF417 in Visual C# The BindingSourceRefresh Control

The BindingSourceRefresh Control
PDF417 Drawer In Visual C#.NET
Using Barcode generator for VS .NET Control to generate, create PDF 417 image in Visual Studio .NET applications.
www.OnBarcode.com
Scan PDF417 In C#
Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
The BindingSourceRefresh control is also an extender control, but its purpose is quite different from the ReadWriteAuthorization control. It turns out that there s a quirk in the way Windows Forms data binding works. The BindingSourceRefresh control helps work around this quirk. The quirk is that when data is changed in a business object, data binding doesn t always display the changes in the controls on the form. This occurs in the following sequence of events:
QR Code JIS X 0510 Creation In Visual C#.NET
Using Barcode generation for .NET framework Control to generate, create QR-Code image in VS .NET applications.
www.OnBarcode.com
Print Data Matrix 2d Barcode In C#.NET
Using Barcode generation for VS .NET Control to generate, create ECC200 image in Visual Studio .NET applications.
www.OnBarcode.com
C HAPTE R 10 DA TA BINDIN G
Make PDF417 In Visual C#.NET
Using Barcode drawer for .NET Control to generate, create PDF-417 2d barcode image in .NET applications.
www.OnBarcode.com
ANSI/AIM Code 39 Drawer In C#.NET
Using Barcode generator for .NET Control to generate, create ANSI/AIM Code 39 image in .NET applications.
www.OnBarcode.com
1. The user edits a value in a bound control. 2. Data binding puts the user s new value into the business object. 3. The business object alters the value in the property set block. 4. The business object raises its PropertyChanged event. You would expect that data binding would handle the PropertyChanged event, realize that the property s data has changed, and then update the control with the new value. And that does happen for all controls except the current control. In other words, the PropertyChanged event causes data binding to refresh all other controls on the form except the control that initiated the change in the first place. Obviously, this can be problematic. Consider a TextBox control that is bound to a business object property that uses a SmartDate. I ll discuss SmartDate in 16, but one of its features is to accept the + character as input and to replace it with tomorrow s date. Due to this data binding quirk, when the user enters a + character, that value is put into the business object, which translates it to tomorrow s date but that new value is not displayed to the user. The user continues to see the + character. What s even more confusing for users is that if they edit a different control, then the date text box control will be updated with tomorrow s date. Remember that data binding updates everything except the current control when it gets a PropertyChanged event. This is the problem BindingSourceRefresh is intended to solve. It does so by interacting with the BindingSource control that manages the data binding for a given business object. While ReadWriteAuthorization extends controls like TextBox and Label, BindingSourceRefresh extends BindingSource controls. The plumbing code in this control is virtually identical to ReadWriteAuthorization, so I won t walk through all the details of the control. This control only extends BindingSource controls, and if it is enabled, it hooks the BindingComplete event raised by the BindingSource control. This event is raised by a BindingSource control after all controls have had their values updated through data binding well, all controls except the current one, of course. The Control_BindingComplete() method takes the extra step of forcing the BindingSource control to refresh the value for the current binding as well. private void Control_BindingComplete( object sender, BindingCompleteEventArgs e) { switch (e.BindingCompleteState) { case BindingCompleteState.Exception: if (BindingError != null) { BindingError(this, new BindingErrorEventArgs(e.Binding, e.Exception)); } break; default: if ((e.BindingCompleteContext == BindingCompleteContext.DataSourceUpdate) && e.Binding.DataSource is BindingSource && GetReadValuesOnChange((BindingSource)e.Binding.DataSource)) { e.Binding.ReadValue(); } break; } }
Drawing Code 128C In Visual C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create Code 128B image in VS .NET applications.
www.OnBarcode.com
Creating Intelligent Mail In Visual C#
Using Barcode generator for .NET Control to generate, create USPS Intelligent Mail image in VS .NET applications.
www.OnBarcode.com
CHAPTER 10 DATA B INDING
Create PDF-417 2d Barcode In Java
Using Barcode encoder for BIRT reports Control to generate, create PDF-417 2d barcode image in BIRT reports applications.
www.OnBarcode.com
PDF417 Printer In None
Using Barcode encoder for Font Control to generate, create PDF 417 image in Font applications.
www.OnBarcode.com
The BindingComplete event includes a BindingCompleteEventArgs parameter, and that parameter includes a property indicating whether the binding process completed with an exception or normally. In the case of an exception, the BindingSourceRefresh control raises its own BindingError event, so the UI developer can be informed that an exception occurred and can take steps. By default, exceptions during binding are silently swallowed by data binding, and the only place you ll see them is in the output window of the debugger in Visual Studio. By raising this event when an error occurs, the control enables the UI developer to more easily detect and troubleshoot data binding issues. The normal case, however, is that the binding succeeds. In that case, the e parameter includes a reference to the currently active Binding object. It is this Binding object that isn t refreshed automatically when data binding gets a PropertyChanged event from the underlying data source. By calling its ReadValue() method, this code forces data binding to read the value from the data source and update the current control s display as well. The BindingSourceRefresh control should be used to force data refreshes for all BindingSource controls bound to detail forms. It isn t necessary when only complex controls such as a GridView or ListBox are bound to the object.
GS1 - 12 Creator In None
Using Barcode generation for Office Word Control to generate, create UPC-A Supplement 5 image in Word applications.
www.OnBarcode.com
Barcode Decoder In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Printing Code 128 Code Set A In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Code 128 Code Set A image in ASP.NET applications.
www.OnBarcode.com
Draw GS1 128 In Java
Using Barcode printer for BIRT reports Control to generate, create EAN / UCC - 14 image in BIRT applications.
www.OnBarcode.com
Denso QR Bar Code Reader In C#.NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Barcode Recognizer In Visual Studio .NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
PDF-417 2d Barcode Generator In None
Using Barcode maker for Software Control to generate, create PDF417 image in Software applications.
www.OnBarcode.com
Print Barcode In Visual Studio .NET
Using Barcode printer for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
Barcode Generator In VS .NET
Using Barcode generation for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
Decoding Code128 In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.