Connection Management in .NET framework

Printer Code128 in .NET framework Connection Management
Connection Management
ANSI/AIM Code 128 Creator In .NET Framework
Using Barcode generator for VS .NET Control to generate, create Code 128A image in .NET applications.
The table adapters that the designer generates contain code to initialize the connection to the database By default, when you drag a table onto the data set designer surface from Server Explorer, an appconfig configuration file is added to your project The connection string to the database you are working with is added to the connectionStrings configuration section in that configuration file: <connectionStrings> <add name="NorthwindDataAccessPropertiesSettings NorthwindConnectionString" connectionString="Data Source=localhost;Initial Catalog=Northwind;Integrated Security=True" providerName="SystemDataSqlClient" /> </connectionStrings>
Scanning USS Code 128 In .NET Framework
Using Barcode reader for .NET Control to read, scan read, scan image in .NET framework applications.
The connectionStrings section is a new part of the configuration file schema for NET 20 The add element that you place under it adds a connection string that will be accessible in the project through a strongly typed Settings class The add tag contains a name attribute that basically specifies a path to a property on a class that will contain the connection string at runtime In this case, that is the NorthwindConnectionString property on the Settings class in the Properties child namespace within theNorthwindDataAccess project The add element also contains a connectionString attribute that specifies the connection string that this entry corresponds to Finally, the providerName attribute specifies the data access provider that the connection string corresponds to The Settings class that is specified in the connection string configuration setting is also created when you first drag a database Object onto the data set designer Visual Studio adds the class and defines the SettingsDesignercs file under the Properties node in Solution Explorer, as shown in Figure 210
Create Bar Code In .NET
Using Barcode creator for Visual Studio .NET Control to generate, create barcode image in VS .NET applications.
Figure 210 Settings and Application Configuration Files in Solution Explorer
Decode Barcode In VS .NET
Using Barcode scanner for VS .NET 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
Code 128A Generation In C#
Using Barcode creator for VS .NET Control to generate, create Code 128C image in VS .NET applications.
The Settings class contains strongly typed properties to programmatically access the settings in your configuration files The connection string that is set when you create your table adapters in the designer is also hard coded as a default into that Settings class, so if the corresponding setting cannot be found in the application configuration file, it at least has the original value of the connection string that it can try to use The table adapter generated with your typed data set uses this Settings class to obtain the connection string when the table adapter initializes the connection object that is encapsulated in it: private void InitConnection() { this_connection = new SystemDataSqlClientSqlConnection(); this_connectionConnectionString = NorthwindDataAccessPropertiesSettings DefaultNorthwindConnectionString; }
Draw Code 128 Code Set C In VS .NET
Using Barcode generation for ASP.NET Control to generate, create USS Code 128 image in ASP.NET applications.
The Default static property on the Settings class returns a singleton instance of the Settings class, through which the other properties, such as NorthwindConnectionString, can be used to get to the underlying configuration data Because the connection string information is embedded in the configuration file, and the table adapter calls through the Settings class to get the connection string out of the configuration file, if you need to change the change the connection string information in the application's configuration file target database in your application, you just have to
Drawing Code 128 Code Set C In Visual Basic .NET
Using Barcode drawer for .NET Control to generate, create Code-128 image in VS .NET applications.
At runtime in NET, configuration files need to be named according to a particular convention and placed in the runtime folder on the application For a Windows Forms application, the configuration file assumes the name of the executable file with a config extension, such as MyDataAppexeconfig For development in Visual Studio, a file named appconfig is added to your project; this lets you set the configuration settings as part of your project When you build a Windows Forms project that contains an appconfig file, that file will be copied into the build output folder and renamed using the convention for the output executable file name If you place your data access code, including typed data set definitions, in a separate data access class library (as you always should for a good layered-application architecture), an appconfig file will still be added to the project This will contain the connection strings for your table adapters, and the Settings class in that project will contain a connection string property to access it However, the appconfig file won't be copied to the build output folder for the class library, because configuration files can only be associated with executable files in a Windows application If you then set a reference to that class library from a Windows Forms project and call the table adapter methods from your application code, the table adapter connections will use the connection string information that was hard coded as a default into the Settings class in the data access class library project If you want to change the connection information used in your application, you need to add the connection string information to the application configuration file for the Windows Forms application The easiest way to do this is to copy the appconfig file from the data access layer project into the Windows Forms project if there isn't already one there If there is already an appconfig file in the Windows Forms project, then you can simply copy the connectionStrings section from the appconfig file in the data access layer project into the appconfig file in the Windows Forms project that will be using the data access layer Then any changes you make to the connectionStrings configuration section in the Windows Forms project will be used by the table adapters in the data access layer code, because it will be loaded through the Settings class in the data access layer If you want additional programmatic control of the connection at runtime, you have to add some code to the assembly where the typed data set definition resides In Listing 24, an internal property exposed on the table adapter, named Connection, gives you access to set or get the SqlConnection object that is being used by the table adapter If you add code to the project containing the typed data set that accesses that property, you can dynamically set or modify the connection object There are two ways you could do this: in a separate helper class, or you could define your own partial class file for the table adapter class and add a method or a property with a different name to expose the underlying private member variable that holds the connection You'll see an example of extending the partial class of the table adapter in the section on supporting transactions If you want to expose connection management on a table adapter by adding a separate class to the assembly, you can do it using a
Printing Bar Code In .NET Framework
Using Barcode maker for .NET Control to generate, create bar code image in .NET framework applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks simple class like the following: using SystemDataSqlClient; using NorthwindDataAccessCustomersDataSetTableAdapters; namespace NorthwindDataAccess { public class CustomersTableAdapterConnectionManager { public static SqlConnection GetConnection( CustomersTableAdapter adapter) { return adapterConnection; } public static void SetConnection(CustomersTableAdapter adapter, SqlConnection connection) { adapterConnection = connection; } } }
Print Code 128 Code Set C In .NET Framework
Using Barcode encoder for VS .NET Control to generate, create Code 128 image in .NET applications.
The GetConnection and SetConnection static methods take a CustomersTableAdapter parameter that is used to access the members of the class The SetConnection method also takes the SqlConnection object that you want to use to set the current connection for the adapter Because the Connection property is declared as internal on the table adapter class, it can be accessed by the methods of other classes in the same assembly that include these helper class methods So the helper class methods simply either get or set the connection through the table adapter reference, even though code external to the assembly could not do so (I think they should have exposed the Connection property as public to avoid needing to do this, but the design choice was made to encapsulate it more rather than less; this requires you to write more code for the cases where you need to access it outside the assembly)
Bar Code Creator In VS .NET
Using Barcode encoder for .NET framework Control to generate, create bar code image in .NET applications.
This document was created by an unregistered ChmMagic, please go to http://wwwbisentercom to register it Thanks
Code 39 Extended Maker In .NET Framework
Using Barcode encoder for .NET framework Control to generate, create Code 39 Full ASCII image in VS .NET applications.
Paint Code 2 Of 5 In VS .NET
Using Barcode maker for .NET Control to generate, create 2/5 Standard image in .NET applications.
Barcode Printer In Visual C#
Using Barcode creator for .NET framework Control to generate, create barcode image in Visual Studio .NET applications.
Paint DataMatrix In Visual Basic .NET
Using Barcode generator for .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
Painting ANSI/AIM Code 128 In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create Code 128C image in ASP.NET applications.
Drawing Bar Code In VS .NET
Using Barcode creation for ASP.NET Control to generate, create barcode image in ASP.NET applications.