Figure 93 CustomBusinessObjectsClient in Action in .NET framework

Create Code 128 Code Set C in .NET framework Figure 93 CustomBusinessObjectsClient in Action
Figure 93 CustomBusinessObjectsClient in Action
Code 128 Code Set A Generation In .NET Framework
Using Barcode encoder for .NET framework Control to generate, create Code-128 image in Visual Studio .NET applications.
[View full size image]
Recognize USS Code 128 In .NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET framework applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
Painting Bar Code In .NET
Using Barcode printer for VS .NET Control to generate, create bar code image in .NET applications.
Setting the Textual Data-Binding Behavior of Custom Objects
Bar Code Scanner In .NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
One thing that you will notice right off the bat is that if a single-valued property on a class is a reference type, such as the Customer property in the Order class, it will show up in the grid by default since this example autogenerates columns Unfortunately, the values that show up there are not particularly meaningful, because what happens is that the grid calls the ToString method on those objects to get a string value for presentation in the grid cell as part of the formatting process The same thing would happen if you bound that property for display in a ComboBox, ListBox, or TextBox control The default ToString method inherited from the SystemObject base class returns the fully qualified type name as a string, which probably isn't what you want to display You could handle this by not autogenerating columns and skipping the display of the Customer property in the grid But depending on the situation, you may want the Customer property to be able to be used for data-binding scenarios, in which case you would want it to display something meaningful when it is used for binding to a textual control The way to do this is to simply override the ToString method in your custom business object In this example, this means adding a ToString override in the implement by simply returning the customer name: public override string ToString() { return m_Name; } Customer class, which you can
Create Code-128 In Visual C#.NET
Using Barcode creator for .NET Control to generate, create USS Code 128 image in .NET framework applications.
Now when you run the sample, the customer name for the parent customer will show up in the Customer column of the orders grid, instead of just the fully qualified type name repeating in every cell of that column
Code128 Creation In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create Code 128C image in ASP.NET applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
Code 128C Creation In VB.NET
Using Barcode generator for .NET framework Control to generate, create ANSI/AIM Code 128 image in .NET applications.
Supporting Transacted Object Editing with IEditableObject
Barcode Drawer In Visual Studio .NET
Using Barcode creator for .NET Control to generate, create barcode image in .NET applications.
If you ran the CustomBusinessObjects sample from the last section, and edited a property on either a Customer or Order object in the grid, then tabbed into the next field, the edit to that property is immediately written to the underlying bound object property If there are any other controls that are data bound to the same object and displaying it, you should see their display immediately update to the new value as well This is because the change was made through a data-bound control, which notifies the currency manager controlling the data binding of the change, and that change will then be rippled to any other bound controls that are in communication with the same currency manager This behavior may or may not be what you want Sometimes when you are editing an object, you want changes to that object to be treated in a transacted way, with all changes to properties of a single object being done all together or not at all Say you have a custom object with three properties bound to controls on a form You edit properties one and two of the object, and then something goes wrong while editing property three Do you want the changes to properties one and two to remain in effect, or do you want them to revert to what they were before the editing operation on that object was initiated Or perhaps you have interdependencies between properties, where the first property can only be between 1 and 10 if it is Tuesday, but otherwise must be between 10 and 20 If the second property tells you what day it is, you won't know whether you have a valid combination of row values until they have all been edited In a transacted world, the changes to those properties could be rolled back to their previous values automatically if something went wrong or if you decided you wanted to abort the object editing process The DataRowView class has built-in support for this kind of thing, as does the DataGridView If you have a data set bound to a grid and start editing the fields in a row and then press the Esc key, the changes you made to that row will be rolled back, changing the values back to their original values before the editing of that row commenced If you shift the focus to a new row with the arrow keys, tab off the last field in a row, press the Enter key, or click on a different control or row in the form, the changes are accepted (committed), and you will no longer have the opportunity to revert them to their previous values Likewise, if your grid is set up to let users add new rows, and they commence entering values for a new row, those entered values have to go somewhere, and the grid is only displaying rows that are actually part of the bound table So once you start editing fields within the empty row at the bottom of a grid that is marked with an asterisk in the row header cell, a new DataRow is actually added to the table and you are editing the fields in that row as you edit the row in the grid But if you press the Esc key during the editing of the new row, the grid is able to remove the row from the table and pretend that it never existed This is another form of transacted object editing, where a new object isn't considered to be fully part of the collection until the initial editing of that newly created object is complete However, for data-binding display purposes, you usually need that object to physically be added to the collection before the editing is complete, so that the entered field or property values have an object in memory on which they can be set and which can be displayed by the normal data-binding mechanisms To support this kind of transacted editing of your objects in a form, you need to implement the IEditableObject interface on the custom object definition This interface includes three methods that you need to implement on your class: BeginEdit, EndEdit, and CancelEdit As you might expect, from a transaction perspective, these operations logically correspond to beginning a transaction, committing the transaction, and rolling back the transaction
Painting Bar Code In .NET
Using Barcode creator for Visual Studio .NET Control to generate, create bar code image in .NET framework applications.
BeginEdit should be called by a data-bound control when an editing operation is commenced against a single instance of an object EndEdit should be called when the editing process is complete If CancelEdit is called anytime between BeginEdit and EndEdit, any changes made since BeginEdit was called should be rolled back CancelEdit shouldn't be called after EndEdit unless BeginEdit is called again to initiate a new transaction
GS1 - 12 Generator In .NET
Using Barcode creator for VS .NET Control to generate, create UPCA image in .NET applications.
What you typically need to do inside the implementation of the interface methods is to cache changes to the object using some temporary variables to keep track of the property's original values before the editing operation commenced from the BeginEdit method Then if editing is completed normally with a call to EndEdit, you can discard the cached original values and treat the current values of the
USS Code 39 Creation In VS .NET
Using Barcode creation for .NET framework Control to generate, create Code 39 Full ASCII image in .NET framework applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
2 Of 5 Interleaved Encoder In .NET Framework
Using Barcode encoder for .NET framework Control to generate, create ANSI/AIM ITF 25 image in Visual Studio .NET applications.
properties as permanent If CancelEdit is called, you should use the cached original values to reset the values of the object properties to their original values To do this on your simple Customer object type requires the following additions to the class: public class Customer : IEditableObject { private int m_OldCustomerId; private string m_OldName; private bool m_Editing; // other fields, properties, and methods public void BeginEdit() { if (!m_Editing) { m_OldCustomerId = m_CustomerId; m_OldName = m_Name; } m_Editing = true; } public void CancelEdit() { if (m_Editing) { CustomerId = m_OldCustomerId; CustomerName = m_OldName; } m_Editing = false; } public void EndEdit() { m_Editing = false; } }
Decode EAN-13 Supplement 5 In .NET Framework
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET applications.
First, you add the IEditableObject interface to your class definition You then need somewhere to stuff the cached original values of properties when an edit operation is in progress To keep the sample simple, this just caches the values of the object's name and ID properties in additional private fields on the class named m_OldCustomerId and m_OldName For a more complex object with many fields, having two of every field would get cluttered, so you could also simplify this process by creating a new instance of your custom object type, populating its fields with the original values, and holding a private reference to that object as the original values to revert to if CancelEdit is called Note that this sets the current values through the properties, rather than directly on the member variables The reason for this will become apparent in the next section As you can see from the code, the BeginEdit method stores the current values of the fields in the cached fields and sets a flag to indicate that you are in edit mode This is necessary because depending on how data binding is hooked up, BeginEdit will likely be called multiple times by the form, and you want to store the old values just when the edit operation really begins, not repeatedly as the rest of the editing process gets going EndEdit effectively accepts the current values by setting the editing flag back to false CancelEdit rolls back the changes by setting the current property values back to the original value using the cached values By implementing IEditableObject like this, your custom business objects will now behave like a data set when being edited in a grid like the DataGridView Specifically, if several properties of a given row have been be rolled back and the original values will be reset on the object edited, and the user presses the Esc key, the changes will
GS1-128 Maker In Java
Using Barcode generation for Java Control to generate, create USS-128 image in Java applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
EAN13 Generation In .NET
Using Barcode creator for ASP.NET Control to generate, create EAN13 image in ASP.NET applications.
This simple implementation doesn't account for the fact that conceptually the Orders collection could also be changed as part of the logical editing of a Customer object You would want to be able to roll back those changes as well since they are child objects, and conceptually they are "part of" a Customer object However, since the IEditableObject interface is primarily used in a data-binding context, you would have to switch the focus to the Orders grid to modify the Orders collection associated with the selectedCustomer, and that change of control focus is going to call EndEdit on the Customer object anyway There may be more advanced scenarios where you might want to use the IEditableObject implementation to support fully transacted editing of an object, whether through a bound control or through programmatic edits, but that isn't really what it was designed for
Encoding UPC Symbol In .NET
Using Barcode drawer for ASP.NET Control to generate, create Universal Product Code version A image in ASP.NET applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
Data Matrix Printer In C#
Using Barcode drawer for .NET framework Control to generate, create ECC200 image in Visual Studio .NET applications.
Paint Bar Code In Visual C#.NET
Using Barcode creation for .NET Control to generate, create barcode image in .NET applications.
Code 39 Extended Drawer In VS .NET
Using Barcode generation for ASP.NET Control to generate, create Code 3 of 9 image in ASP.NET applications.