EndOpen Method

On this page

Ends an asynchronous invocation of the Open method.

Syntax

Visual Basic
C#


'Declaration Public Sub EndOpen( _ ByVal result As IAsyncResult _ )


public void EndOpen( IAsyncResult result )

Parameters

result: The System.IAsyncResult returned from BeginOpen.

Remarks

BeginOpen method enables you to open a connection to server without having current thread blocked. In other words, your program can continue execution while the connection is establishing so you do not have to wait for it.

To start opening a connection, you have to call BeginOpen method, which in turn invokes appropriate actions in another thread. Return value of this method must be assigned to System.IAsyncResult object. After executing this method program flow continues.

When you are ready to use the connection, call EndOpen. If at the moment you call this method the negotiation process has not yet been finished, application stops and waits till the function returns which means that the connection is open.

Example

This sample shows how to implement asynchronous opening of a connection.

csharp


public void AsyncOpen(DbConnectionBase myConnection) { IAsyncResult myAsyncResult = myConnection.BeginOpen(null, null); DbCommandBase myCommand = (DbCommandBase)myConnection.CreateCommand(); myCommand.CommandText = "INSERT INTO Dept(DeptNo, DName) Values('100', 'DEVELOPMENT')"; //some operations here myConnection.EndOpen(myAsyncResult); try { myCommand.ExecuteNonQuery(); } finally { myConnection.Close(); } }

public void AsyncOpen(DbConnectionBase myConnection)
{
  IAsyncResult myAsyncResult = myConnection.BeginOpen(null, null);
  DbCommandBase myCommand = (DbCommandBase)myConnection.CreateCommand();
  myCommand.CommandText = "INSERT INTO Dept(DeptNo, DName) Values('100', 'DEVELOPMENT')";
  //some operations here
  myConnection.EndOpen(myAsyncResult);
  try
  {
    myCommand.ExecuteNonQuery();
  }
  finally
  {
    myConnection.Close();
  }
}

Visual Basic


Public Sub AsyncOpen(ByVal myConnection As DbConnectionBase) Dim myAsyncResult As IAsyncResult = myConnection.BeginOpen(Nothing, Nothing) Dim myCommand As DbCommandBase = myConnection.CreateCommand() myCommand.CommandText = "INSERT INTO Dept(DeptNo, DName) Values('110', 'QA')" ' some operations here myConnection.EndOpen(myAsyncResult) Try myCommand.ExecuteNonQuery() Finally myConnection.Close() End Try End Sub

Public Sub AsyncOpen(ByVal myConnection As DbConnectionBase)
  Dim myAsyncResult As IAsyncResult = myConnection.BeginOpen(Nothing, Nothing)
  Dim myCommand As DbCommandBase = myConnection.CreateCommand()
  myCommand.CommandText = "INSERT INTO Dept(DeptNo, DName) Values('110', 'QA')"
  ' some operations here
  myConnection.EndOpen(myAsyncResult)
  Try
    myCommand.ExecuteNonQuery()
  Finally
    myConnection.Close()
  End Try
End Sub

Reference

DbConnectionBase Class
DbConnectionBase Members

Send Feedback