我有一个C#数据表,其中包含1000行。但是主要的200行具有空值(多列)。那些列将作为空值进行过滤,以最后占据。我希望输出将在带有过滤器的表或新表中发生,但不会出现在linq行中。请帮帮我
图片讲的更多话,请参考以更好地理解:
这里您应该考虑两件事:
.OrderBy(s => String.IsNullOrEmpty(s["OrderNo"].ToString()))
IComparer<string>
。正如您在问题中所显示的,我假设IComparer<string>
的格式可以是Order No
或XXXXX
。 因此,您需要首先XXXX-XXXX
空值OrderBy
您的自定义ThenBy
像这样:
IComparer<string>
完整示例在这里:
public class OrderNoComparer : IComparer<string>
{
public int Compare(string x, string y)
{
int xFirstValue = 0;
int xSecondValue = 0;
int yFirstValue = 0;
int ySecondValue = 0;
if (x.Contains("-"))
{
xFirstValue = Convert.ToInt32(x.Split(new char[] { '-' })[0]);
xSecondValue = Convert.ToInt32(x.Split(new char[] { '-' })[1]);
}
else
{
xFirstValue = Convert.ToInt32(x);
}
if (y.Contains("-"))
{
yFirstValue = Convert.ToInt32(y.Split(new char[] { '-' })[0]);
ySecondValue = Convert.ToInt32(y.Split(new char[] { '-' })[1]);
}
else
{
yFirstValue = Convert.ToInt32(y);
}
if (xFirstValue > yFirstValue)
{
return 1;
}
else if (xFirstValue < yFirstValue)
{
return -1;
}
else //means equal
{
if (xSecondValue > ySecondValue)
{
return 1;
}
else if (xSecondValue == ySecondValue)
{
return 0;
}
else
{
return -1;
}
}
}
}
然后输出将像您期望的那样:
DataTable dtOrder = new DataTable();
dtOrder.Columns.Add("OrderNo");
var dr1 = dtOrder.NewRow();
dr1["OrderNo"] = "";
dtOrder.Rows.Add(dr1);
var dr2 = dtOrder.NewRow();
dr2["OrderNo"] = "569-875";
dtOrder.Rows.Add(dr2);
var dr3 = dtOrder.NewRow();
dr3["OrderNo"] = "569975";
dtOrder.Rows.Add(dr3);
var dr4 = dtOrder.NewRow();
dr4["OrderNo"] = "569865";
dtOrder.Rows.Add(dr4);
var dr5 = dtOrder.NewRow();
dr5["OrderNo"] = "569-975";
dtOrder.Rows.Add(dr5);
var dr6 = dtOrder.NewRow();
dr6["OrderNo"] = "569-875";
dtOrder.Rows.Add(dr6);
var result = dtOrder.AsEnumerable().AsQueryable()
.OrderBy(s => String.IsNullOrEmpty(s["OrderNo"].ToString()))
.ThenBy(o => o["OrderNo"].ToString(), new OrderNoComparer())
.ToList();
foreach (var item in result)
{
Console.WriteLine(item["OrderNo"]);
}