Here is the most popular version of the implementation of this design pattern :
public class Singleton
{
private static Singleton instance;
private object oSync = new object();
public Singleton ()
{
}
public static Singleton Instance
{
get
{
if(instance == null)
{
Lock(oSync)
{
if(instance == null)
{
instance = new Singleton();
}
}
}
return instance;
}
}
}
this version is not optimized for .Net. In .Net we can use a static constructor and this static constructor is ThreadSafe.
Here is the optimized version :
public class Singleton
{
private static Singleton instance = new Singleton ();
private object oSync = new object();
static Singleton ()
{
}
private Singleton ()
{
}
public static Singleton Instance
{
get
{
return instance;
}
}
}
mercredi 17 octobre 2007
jeudi 27 septembre 2007
SSIS Excel data source values returned as null
This problem occurs when we try to import an Excel file. All values of a column are returned in SSIS as null values but in the document we had values.
The problem is due to the provider : the provider calculate the data type of a column by analysing the first lines of the document.
The solution is to modify the ConnectionString property of the ExcelConnection component (add IMEX=1)
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\data\maroc\import.xls; Extended Properties="EXCEL 8.0;HDR=YES;IMEX=1;"
IMEX=1: indicates the provider to convert data, in multitype columns, to text values.
SEE :http://support.microsoft.com/kb/194124/en-us
The problem is due to the provider : the provider calculate the data type of a column by analysing the first lines of the document.
The solution is to modify the ConnectionString property of the ExcelConnection component (add IMEX=1)
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\data\maroc\import.xls; Extended Properties="EXCEL 8.0;HDR=YES;IMEX=1;"
IMEX=1: indicates the provider to convert data, in multitype columns, to text values.
SEE :http://support.microsoft.com/kb/194124/en-us
Building ClickOnce application from the command line(Without VS2005)
I was looking for an alternative to use VS 2005 for publishing an application, And I found that MSBuild allow us to do that. the solution consists of using the .csproj file generated by visual studio and this command line : msbuild /target:publish.
A detailed explanation is available here : Building ClickOnce Applications from the Command Line
A detailed explanation is available here : Building ClickOnce Applications from the Command Line
mardi 18 septembre 2007
Nouveauté du framework 2.0
ayant travailler essentiellement sur .Net 2.0, je ne pouvais pas répondre à cette question qui est souvent posé lors des entretient d'ambauche : quelles sont les nouvautés du framework 2.0 ?
Des éléments de réponses sont disponible à cette adresse :
Les nouveautés du framework 2.0
Des éléments de réponses sont disponible à cette adresse :
Les nouveautés du framework 2.0
lundi 17 septembre 2007
Welcome to .Net Generation
In this blog you will find essentially, technical postes about .Net technologies.
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