Count, propriété – Exemple (VJ++)

S’applique à : Access 2013, Office 2013

Cet exemple illustre la propriété Count avec deux collections dans la base de données Employees . La propriété obtient le nombre d’objets de chaque collection et définit la limite supérieure pour les boucles qui énumèrent ces collections. Une autre façon d’énumérer ces collections sans utiliser la propriété Count consiste à utiliser des instructions.

 
// BeginCountJ 
import com.ms.wfc.data.*; 
import java.io.* ; 
 
public class CountX 
{ 
 // The main entry point for the application. 
 
 public static void main (String[] args) 
 { 
 CountX(); 
 System.exit(0); 
 } 
 
 // CountX function 
 
 static void CountX() 
 { 
 
 // Define ADO Objects. 
 Recordset rstEmployees = null; 
 
 // Declarations. 
 BufferedReader in = 
 new BufferedReader (new InputStreamReader(System.in)); 
 String line = null; 
 String strCnn = "Provider='sqloledb';Data Source='MySqlServer';" 
 + "Initial Catalog='Pubs';Integrated Security='SSPI';"; 
 
 int intLoop; 
 int intDisplaySize = 20; 
 int recCount=0; 
 
 try 
 { 
 rstEmployees = new Recordset(); 
 
 // Open recordset with data from Employees table. 
 rstEmployees.open("employee", strCnn, 
 AdoEnums.CursorType.FORWARDONLY, 
 AdoEnums.LockType.READONLY, 
 AdoEnums.CommandType.TABLE); 
 
 // Print information about Fields collection. 
 System.out.println(rstEmployees.getFields().getCount() + 
 " Fields in Employees"); 
 for ( intLoop = 0; intLoop < 
 rstEmployees.getFields().getCount(); intLoop++) 
 { 
 System.out.println("\t" + 
 rstEmployees.getFields().getItem(intLoop).getName()); 
 } 
 System.out.println("\n\nPress <Enter> to continue.."); 
 in.readLine(); 
 
 // Print information about Properties collection. 
 System.out.println(rstEmployees.getProperties().getCount() + 
 " Properties in Employees"); 
 for ( intLoop = 0; intLoop < 
 rstEmployees.getProperties().getCount(); intLoop++) 
 { 
 System.out.println("\t" + 
 rstEmployees.getProperties().getItem(intLoop).getName()); 
 recCount++; 
 if ( recCount >= intDisplaySize) 
 { 
 System.out.println("\n\nPress <Enter> to continue.."); 
 in.readLine(); 
 recCount = 0; 
 } 
 } 
 System.out.println("\n\nPress <Enter> to continue.."); 
 in.readLine(); 
 
 } 
 catch( AdoException ae ) 
 { 
 // Notify user of any errors that result from ADO. 
 
 // Check for null pointer for connection object. 
 if (rstEmployees.getActiveConnection()==null) 
 { 
 System.out.println("Exception: " + ae.getMessage()); 
 } 
 else 
 { 
 // As passing a Recordset, check for null pointer first. 
 if (rstEmployees != null) 
 { 
 PrintProviderError(rstEmployees.getActiveConnection()); 
 } 
 else 
 { 
 System.out.println("Exception: " + ae.getMessage()); 
 } 
 } 
 } 
 
 // System read requires this catch. 
 catch( java.io.IOException je) 
 { 
 PrintIOError(je); 
 } 
 
 finally 
 { 
 // Cleanup objects before exit. 
 if (rstEmployees != null) 
 if (rstEmployees.getState() == 1) 
 rstEmployees.close(); 
 } 
 } 
 
 // PrintProviderError Function 
 
 static void PrintProviderError( Connection Cnn1 ) 
 { 
 // Print Provider errors from Connection object. 
 // ErrItem is an item object in the Connections Errors collection. 
 com.ms.wfc.data.Error ErrItem = null; 
 long nCount = 0; 
 int i = 0; 
 
 nCount = Cnn1.getErrors().getCount(); 
 
 // If there are any errors in the collection, print them. 
 if( nCount > 0); 
 { 
 // Collection ranges from 0 to nCount - 1 
 for (i = 0; i< nCount; i++) 
 { 
 ErrItem = Cnn1.getErrors().getItem(i); 
 System.out.println("\t Error number: " + ErrItem.getNumber() 
 + "\t" + ErrItem.getDescription() ); 
 } 
 } 
 
 } 
 
 // PrintIOError Function 
 
 static void PrintIOError( java.io.IOException je) 
 { 
 System.out.println("Error \n"); 
 System.out.println("\tSource = " + je.getClass() + "\n"); 
 System.out.println("\tDescription = " + je.getMessage() + "\n"); 
 } 
} 
 
// EndCountJ