c# data matrix generator ansaction in C#

Generate Data Matrix ECC200 in C# ansaction

ansaction
Data Matrix 2d Barcode Printer In C#.NET
Using Barcode creator for Visual Studio .NET Control to generate, create Data Matrix 2d barcode image in .NET applications.
www.OnBarcode.com
Data Matrix ECC200 Scanner In C#
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 12 TRANSACTIONS
Code 128C Generator In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create Code 128 Code Set A image in VS .NET applications.
www.OnBarcode.com
Encode Code39 In C#.NET
Using Barcode creator for VS .NET Control to generate, create Code 39 Full ASCII image in VS .NET applications.
www.OnBarcode.com
Notice that each level in the stack must call Complete. If any level fails to call Complete, then the entire transaction is doomed up and down all levels of the call stack.
Matrix Barcode Maker In C#
Using Barcode encoder for VS .NET Control to generate, create Matrix image in .NET framework applications.
www.OnBarcode.com
PDF417 Maker In C#.NET
Using Barcode generator for .NET Control to generate, create PDF 417 image in VS .NET applications.
www.OnBarcode.com
Transacted Types
Linear Barcode Creator In Visual C#.NET
Using Barcode creation for VS .NET Control to generate, create Linear 1D Barcode image in .NET applications.
www.OnBarcode.com
EAN-8 Supplement 2 Add-On Generator In C#.NET
Using Barcode creation for .NET Control to generate, create GS1 - 8 image in .NET framework applications.
www.OnBarcode.com
So far we have illustrated the simplified transaction model for updates of either a single database or many databases, which when you re using SQL Server 2005 will leverage either a lightweight transaction or the DTC. Support also exists for creating your own transacted types, which can affect memory, the file system, or any other resource you need to manage in your application. Creating your own transacted type involves implementing, at a minimum, the IEnlistmentNotification interface. Consider the follow example. Here you move orders from an XML file into the same database you used in the previous example. (See XActedDomTest.aspx in the Web12 project.) private void WOATx() { XmlDocument dom = new XmlDocument(); dom.Load(Server.MapPath("Orders.xml")); XmlNode orderElem; XmlNode ordersElem = dom.SelectSingleNode("//Orders"); int orderCount = ordersElem.ChildNodes.Count; for (int i = orderCount - 1; i >= 0; i--) { orderElem = ordersElem.ChildNodes[i]; orderElem.ParentNode.RemoveChild(orderElem); AddOrder(orderElem); } dom.Save(Server.MapPath("UnprocessedOrders.xml")); } The AddOrder method leverages the methods from the previous example to create the order in the database. In this case, instead of using the hash table like the previous example, it s using the data read from the XML document. (See XActedDomTest.aspx in the Web12 project.) private bool AddOrder(XmlNode orderElem) { DateTime orderDate = Convert.ToDateTime(orderElem.Attributes["OrderDate"].Value); int customerId = Convert.ToInt32(orderElem.Attributes["CustomerID"].Value); XAction dal = new XAction(); int orderID = XAction.GetNextOrderID(); dal.AddOrder(orderID, customerId, orderDate); bool bSuccess = true;
DataMatrix Creator In Visual Studio .NET
Using Barcode maker for Visual Studio .NET Control to generate, create Data Matrix image in .NET framework applications.
www.OnBarcode.com
Recognize Data Matrix 2d Barcode In VB.NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
CHAPTER 12 TRANSACTIONS
EAN128 Creator In None
Using Barcode creation for Microsoft Excel Control to generate, create USS-128 image in Excel applications.
www.OnBarcode.com
PDF-417 2d Barcode Decoder In C#
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
foreach(XmlNode orderItem in orderElem.ChildNodes) { int itemID = Convert.ToInt32(orderItem.Attributes["ItemId"].Value); int quantity = Convert.ToInt32(orderItem.Attributes["Quantity"].Value); bSuccess = dal.AddOrderItem(orderID, itemID, quantity); if (!bSuccess) break; } return bSuccess; } What happens when you run into an item that s not in stock The creation of the order and corresponding order items will be rolled back, but you ve lost the changes describing the order in your XML document. Your goal here is to have the instance of XMLDocument also participate in the transaction. When the transaction fails, any changes you ve made to the tree of elements in the document instance will be rolled back as well. To do this you ll create a type that extends XMLDocument. The first thing you ll need to do with this type is implement IEnlistmentNotification. Table 12-1 shows the methods this interface requires you to implement. Table 12-1. Methods of the IEnlistmentNotification Interface
Creating ANSI/AIM Code 39 In None
Using Barcode creation for Software Control to generate, create Code39 image in Software applications.
www.OnBarcode.com
GS1 - 13 Printer In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create European Article Number 13 image in Visual Studio .NET applications.
www.OnBarcode.com
Method
Recognize Code 3 Of 9 In Visual Basic .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Barcode Scanner In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Commit InDoubt Prepare Rollback
DataBar Drawer In Java
Using Barcode creation for Java Control to generate, create DataBar image in Java applications.
www.OnBarcode.com
Generate Code 39 Extended In Java
Using Barcode maker for Java Control to generate, create Code39 image in Java applications.
www.OnBarcode.com
Meaning in Life
Paint ECC200 In None
Using Barcode creator for Microsoft Excel Control to generate, create Data Matrix ECC200 image in Office Excel applications.
www.OnBarcode.com
Code 39 Extended Reader In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Called when the transaction is being committed. Called when the outcome of the transaction is not certain (meaning, in real terms, that it s doomed). Called when the transaction is about to be committed. Called when the transaction has failed and the object should be restored to its original state.
So your responsibility as a transaction supporter is to maintain enough state to track the changes that occur during the transaction, and be able to revert to the original state of the document in the event of a rollback. When the transaction is completed, you should also make appropriate changes to the state of your type to commit any modifications made during the transaction. Here s the implementation of the IEnlistmentNotification interface. (See TransDOM.cs in the App_Code directory of the Web12 project.) public class TransactedXMLDocument : XmlDocument, IEnlistmentNotification { private string orgXml; public void Enlist() { orgXml = this.InnerXml; Transaction.Current.EnlistVolatile(this, EnlistmentOptions.None); }
CHAPTER 12 TRANSACTIONS
public void Commit(Enlistment enlistment) { orgXml = ""; enlistment.Done(); } public void InDoubt(Enlistment enlistment) { this.LoadXml(orgXml); orgXml = ""; } public void Prepare(PreparingEnlistment preparingEnlistment) { preparingEnlistment.Prepared(); } public void Rollback(Enlistment enlistment) { this.LoadXml(orgXml); orgXml = ""; } } In this implementation you re tracking the state of the XML document at the point it enters into a transaction using the XML representing the tree at that moment. Any changes made to the tree during the transaction will be reflected in the instance via normal processing that occurs from the base class. Only in the case if the transaction is in doubt or rolled back do you need to take action, and you simply restore the document to its original state by reloading the underlying XML. This strategy does force your user to call the Enlist method to tie it into a transaction. By calling EnlistVolatile and passing a reference to your instance (via this), you wire your type into the rest of the transaction processing. The transaction infrastructure will automatically call Commit or Rollback when the outcome of the transaction becomes known. Let s modify the preceding document processing loop to leverage the new transactional functionality of this type. (See TransactedDomTest.aspx in the Web12 project.) private void WithATran() { TransactedXMLDocument dom = new TransactedXMLDocument(); dom.Load(Server.MapPath("Orders.xml")); XmlNode orderElem; XmlNode ordersElem = dom.SelectSingleNode("//Orders"); int orderCount = ordersElem.ChildNodes.Count; for (int i = orderCount - 1; i >= 0; i--) { orderElem = ordersElem.ChildNodes[i];
Copyright © OnBarcode.com . All rights reserved.