ASP.net C# LINQ for 循环

Question

// Load all the links
ArtworkingDataContext dc = new ArtworkingDataContext();
var q = (from Labels in dc.tblArtworkLabels where Labels.templateID == this.ID select new { LabelID = Labels.ID });

// Create labels array
this.Labels = new ArtworkLabel[q.Count()];
for (int i = 0; i < q.Count(); i++)
{
    this.Labels[i] = new ArtworkLabel(q.LabelID);
}

q.LabelID 不起作用，我不能真正使用 foreach，因为我必须在每次迭代时调用一个新的 ArtworkLabel。

Answer 1

这可行：

var queryList = q.ToList();
for (int i = 0; i < queryList.Count; i++)
{
    this.Labels[i] = new ArtworkLabel(queryList[i].LabelID);
}

您也可以直接从查询中进行投影：

this.Labels = dc.tblArtworkLabels
                .Where( x=> x.templateId == this.Id)
                .Select( x=> new ArtworkLabel(x.ID))
                .ToArray();

Answer 2

尝试这样：

this.Labels = q.Select(x => new ArtworkLabel(x.LabelID)).ToArray();

Answer 3

你可能会这样做，对吧？

ArtworkingDataContext dc = new ArtworkingDataContext();

this.Labels = 
    from label in dc.tblArtworkLabels 
    where label.templateID == this.ID
    select new ArtworkLabel(label.ID).ToArray();

Answer 4

您应该能够在一个 linq 语句中完成这一切。

ArtworkingDataContext dc = new ArtworkingDataContext();
this.Labels = (from Labels in dc.tblArtworkLabels where Labels.templateID == this.ID select new ArtworkLabel(Labels.ID)).ToArray();

Answer 5

我最近尝试了这个，一个 linq for 循环..这就是我想出的..

        var query = from ii in Enumerable.Range(0, xml.AllIndexesOf("<item").Count())
                    where ii < xml.AllIndexesOf("<item").Count()
                    select new { Start = xml.AllIndexesOf("<item").ToList()[sii], Count = xml.AllIndexesOf("</item").ToList()[sii] - xml.AllIndexesOf("<item").ToList()[sii] };