generate barcode image vb.net try { MyConnectionOpen(); } catch in C#.NET

Paint UPC A in C#.NET try { MyConnectionOpen(); } catch

try { MyConnectionOpen(); } catch
Print UPC-A In C#
Using Barcode generation for .NET framework Control to generate, create UPC-A Supplement 2 image in .NET applications.
Scanning UPC Code In C#
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
20: Data in Windows Forms
Barcode Maker In Visual C#
Using Barcode drawer for .NET Control to generate, create barcode image in .NET framework applications.
Scan Bar Code In C#.NET
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
{ Code your exception handling here }
Drawing UPC-A In Visual Studio .NET
Using Barcode generator for ASP.NET Control to generate, create UPC Code image in ASP.NET applications.
Create GS1 - 12 In Visual Studio .NET
Using Barcode encoder for .NET Control to generate, create GTIN - 12 image in .NET applications.
Be sure to close the connection when you are finished with it The garbage collector can then destroy the object and free the memory space:
Generating Universal Product Code Version A In VB.NET
Using Barcode creator for .NET Control to generate, create UPCA image in VS .NET applications.
Code 128C Drawer In C#.NET
Using Barcode generator for .NET Control to generate, create ANSI/AIM Code 128 image in .NET applications.
try { MyConnectionClose(); } catch { Etc }
Making Barcode In C#.NET
Using Barcode printer for VS .NET Control to generate, create bar code image in .NET framework applications.
ANSI/AIM Code 39 Printer In Visual C#.NET
Using Barcode printer for .NET framework Control to generate, create Code-39 image in Visual Studio .NET applications.
PART III
Print EAN 13 In Visual C#
Using Barcode creation for .NET framework Control to generate, create EAN13 image in .NET applications.
UPC - 8 Maker In C#.NET
Using Barcode creator for .NET Control to generate, create EAN-8 Supplement 5 Add-On image in VS .NET applications.
Creating a Command Object
Data Matrix 2d Barcode Printer In Objective-C
Using Barcode generator for iPhone Control to generate, create Data Matrix ECC200 image in iPhone applications.
Bar Code Reader In Visual C#.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
The next step is to create the object that encapsulates the code that you want executed on the data source This could be a stored procedure on the database server or a configured SQL statement located in your code Either way, you need a Command object to do this for you The command object will use the connection object to access the database (or it can provide its own connection data) Once the command is executed against the data source, the data is returned to the user in the form of a stream (read by DataReader objects) or a DataSet object The following code is used to instantiate a command object:
Barcode Reader In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
Code 128 Code Set B Reader In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
SqlCommand MyCommand = new SqlCommand();
Print UPC-A Supplement 2 In None
Using Barcode printer for Microsoft Word Control to generate, create UPCA image in Word applications.
Linear 1D Barcode Creator In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create 1D Barcode image in ASP.NET applications.
You can also use the connection object to create the command object The connection object has a CreateCommand() method that you can use to instantiate your command object
Code 39 Extended Encoder In Java
Using Barcode drawer for Java Control to generate, create Code 39 Full ASCII image in Java applications.
Barcode Maker In Visual Basic .NET
Using Barcode drawer for .NET Control to generate, create bar code image in Visual Studio .NET applications.
comString = "SELECT * FROM Student"; SqlCommand MyCommand = MyConnectionCreateCommand();
Once the command object is created, you can use the execute methods associated with an SqlCommand object:
SqlDataReader myReader = myCommandExecuteReader();
The execute methods include ExecuteScalar() (a command that returns a single value), ExecuteReader() (a command that returns a set of rows), ExecuteNonQuery() (a command that affects the database but only returns the number of rows affected), and ExecuteXmlReader (a command that returns XML data) EXAM TIP or later ExecuteXmlReader() is used for Microsoft SQL Server 70
Some of the properties of a command object are listed in Table 20-5
MCAD/MCSD Visual C# NET Certification All-in-One Exam Guide
Property Description
CommandType CommandText Connection Name Parameters Table 20-5
The type can be one of StoredProcedure, Text, or TableDirect This is the name of the stored procedure, the actual SQL statement, or the name of the table This specifies the connection object (or information) required to access the data source This is a programmatic name that you can use within your program to refer to the command object These are the parameters associated with the stored procedure
Some Properties of the Command Object
Figure 20-30 shows code that instantiates and uses a command object
DataAdapter and DataSet
We can now create a DataAdapter and a DataSet in order to get ready to bind our data to the controls on the form Recall that a DataAdapter is a link between the data source and a DataSet The DataSet is a representation (or local copy) of the actual data from the data source These two objects work hand-in-hand to provide a link to the actual data Let s start with the DataAdapter There are two data adapters SqlDataAdapter and OleDbDataAdapter Since we are connecting to Microsoft SQL Server 70 or higher, we will use the SqlDataAdapter Create a new DataAdapter using the command object:
SqlCommand studentCommand = new SqlCommand(); studentCommandCommandType = CommandTypeText; studentCommandCommandText = "SELECT * FROM Student"; SqlDataAdapter studentAdapter = new SqlDataAdapter(studentCommand);
We can then use this data adapter to create the DataSet object that will be a copy of the actual data retrieved through the command object:
DataSet studentSet = new DataSet(); studentAdapterFill (studentSet, "FirstName");
Figure 20-27
Creating a command object
20: Data in Windows Forms
You can now use all of the binding techniques that you learned earlier in this chapter to bind the data from the data set to any control on your form The following code listing shows the full code required to fill the form (Figure 20-18) with data retrieved from the Microsoft SQL Server database
using System; using SystemDrawing; using SystemCollections; using SystemComponentModel; using SystemWindowsForms; using SystemData; using SystemDataSqlClient; namespace WindowsApplication2 { public class Form1 : SystemWindowsFormsForm { private SystemWindowsFormsButton button1; protected SqlConnection studentConnection; protected SqlCommand studentCommand; protected SqlDataAdapter studentAdapter; protected DataSet studentSet; private SystemWindowsFormsButton btnGetData; private SystemWindowsFormsTextBox txtFirstName; private SystemComponentModelContainer components = null; public Form1() { InitializeComponent(); } protected override void Dispose( bool disposing ) { if( disposing ) { if (components != null) { componentsDispose(); } } baseDispose( disposing ); } [STAThread] static void Main() { ApplicationRun(new Form1()); } private void InitializeComponent() { thisbtnGetData = new SystemWindowsFormsButton(); thistxtFirstName = new SystemWindowsFormsTextBox(); thisSuspendLayout(); // // btnGetData // thisbtnGetDataLocation = new SystemDrawingPoint(97, 124); thisbtnGetDataName = "btnGetData"; thisbtnGetDataTabIndex = 0; thisbtnGetDataText = "GetData"; thisbtnGetDataClick += new SystemEventHandler(thisbtnGetData_Click_1); // // txtFirstName
Copyright © OnBarcode.com . All rights reserved.