Cache Nasil Kullanilir – 3

Selam Bu metodu gride object data source olarak ekledim ama tam burada ds = ((DataSet)(cache[“names”]));>>>> “Object reference not set to an instance of an object.” bu hatayı alıyorum neden olabilir.

public static class Listeler
{
static Cache cache = new Cache();
public static DataSet Get(int isApproval, int jobTypeID, int isInvoiceApproval)
{

DataSet ds;
ds = ((DataSet)(cache[“names”]));

if (ds == null)
{
string path = “JobSma.xml”;
var j = new JobRepositoy();
j.Criteria = “SELECT ……………….. FROM …………………….. WHERE (Retailer.RetailerCode IS NOT NULL) AND (Jobs.IsApproval = @p1) AND (Jobs.JobTypeID = @p2) AND (Jobs.IsInvoiceApproval = @p3) ORDER BY Jobs.JobID DESC”;
j.Parameters.AddWithValue(“@p1”, isApproval);
j.Parameters.AddWithValue(“@p2”, jobTypeID);
j.Parameters.AddWithValue(“@p3”, isInvoiceApproval);
j.GetJoinedEntities().WriteXml(path);

ds = new DataSet();
ds.ReadXml(path);
CacheDependency cd = new CacheDependency(path);
cache.Insert(“names”, ds, cd);
//Trace.Warn(“XML den Yüklendi!”);
}
else
{
//Trace.Warn(“Cache’den Yüklendi!”);
}

return ds;
}
}