private void shiftIndexes(Category entry, int oldIndex, System.Data.Entity.DbSet <Category> dbset)
{
if (entry.Index - oldIndex == 1)
{
//Move forward by 1 step
try
{
dbset.First(x => x.Index == entry.Index).Index = oldIndex; //If was last row - it will throw an exception
}
catch (Exception e)
{ }
}
else if (entry.Index > oldIndex)
{
//We moved forward
foreach (var q in dbset.ToList())
{
if (oldIndex < q.Index && q.Index < entry.Index)
{
q.Index = q.Index - 1;
}
}
entry.Index = entry.Index - 1;
}
else if (entry.Index < oldIndex)
{
//We moved backwards
foreach (var q in dbset.ToList())
{
if (entry.Index <= q.Index && q.Index < oldIndex)
{
q.Index = q.Index + 1;
}
}
}
if (entry.Index > dbset.Count())
{
entry.Index = dbset.Count();
}
else if (entry.Index < 1)
{
entry.Index = 1;
}
}
public virtual List <T> QueryByPage <TKey>(int pageindex
, int pagesize
, out int totalcount
, Expression <Func <T, bool> > where
, Expression <Func <T, TKey> > order)
{
//1.0 计算跳过的总行数
int skipCount = (pageindex - 1) * pagesize;
//2.0 获取满足条件的总行数
totalcount = _dbset.Count(where);
//3.0 查询
return(_dbset.Where(where).OrderByDescending(order).Skip(skipCount).Take(pagesize).ToList());
}
public ActionResult DeleteConfirmed(int id)
{
Category category = db.Categories.Find(id);
System.Data.Entity.DbSet <Category> dbset = db.Categories;
int oldIndex = category.Index;
category.Index = dbset.Count() + 100;
shiftIndexes(category, oldIndex, dbset);
db.Categories.Remove(category);
db.SaveChanges();
return(RedirectToAction("Index"));
}