To export an ADO.NET connection from a PowerBuilder Classic application, use the GetAdoConnection method:
oleobject GetAdoConnection()
The method returns an instance of IAdoConnectionProxy. The proxy’s ADO connection object is assigned to property IAdoConnectionProxy.Connection.
When a transaction starts, the proxy’s active Transaction object is assigned to property IAdoConnectionProxy.Transaction, and AutoCommit is false. When AutoCommit is true, the exported IAdoConnectionProxy.Transaction is null..
The method returns null if the connection fails, and false if the operation fails.
To use the shared connection, your third-party assembly must reference the exported connection proxy and manage the transaction. To be notified when the active transaction is changed, you can subscribe the IAdoConnection.TransactionChanged event . Remember to close the connection.
//Sample PowerScript code
SQLCA.DBMS = "ADO.NET"
SQLCA.AutoCommit = false
SQLCA.DBParm = "Namespace='System.Data.Odbc',
DataSource='SQL
Anywhere 11 Demo'"
Connect Using SQLCA;
emp.ConnectionProxy = SQLCA.GetAdoConnection()
// db operations
disconnect using SQLCA;
Here is an example of C# code in the third-party assembly:
// Manage the transaction
public class Emp {
...
IAdoConnectionProxy proxy;
IDbTransaction trans;
...
public object ConnectionProxy {
get { return proxy; }
set {
proxy = value as IAdoConnectionProxy;
...
proxy.TransactionChanged += new
EventHandler(proxy_TransactionChanged);
}
}
void proxy_TransactionChanged(object sender, EventArgs
e) {
...
trans = sender as IDbTransaction;
...
}
...
}
