我有以下问题,我想寻求帮助。我必须选择不同的值(一个属性的标准(,然后从其他属性中提取不同的值。
假设我有以下类,其中每个BOM
都有一个或多个具有不同Parts
和QtyPer
的FlatComponents
。
示例:
public sealed class BOM {
public string FlatComponent {
get;
set;
}
public string Part {
get;
set;
}
public string QtyPer {
get;
set;
}
public BOM(String flatComponent, String part, String qtyPer) {
this.FlatComponent=flatComponent;
this.Part=part;
this.QtyPer=qtyPer;
}
}
List<BOM> list=new List<BOM>();
list.Add(new BOM("a", "1", "2"));
list.Add(new BOM("a", "3", "4"));
list.Add(new BOM("b", "5", "6"));
list.Add(new BOM("c", "7", "8"));
list.Add(new BOM("c", "9", "0"));
如何使用LINQ(用逗号分隔(在每个属性中选择不同的FlatComponents
及其不同的值?
结果=[["a","1,3","2,4"],["b","5","6"],["c","7,9","8,0"]]
我试过使用.Distinct()
,但我对LINQ还很陌生。。。
试试这个:
var result = list
.GroupBy(e => e.FlatComponent)
.Select(e => new BOM
{
FlatComponent = e.Key,
Part = string.Join(", ", e.Select(x => x.Part)),
QtyPer = string.Join(", ", e.Select(x => x.QtyPer))
});
它将为每个FlatComponent
创建一个不同的BOM
,将Part
和QtyPer
属性与", "
连接起来。
您通常可以使用GroupBy
在LINQ中完成不同的操作。这将以您为所需结果提供的格式生成结果:
IEnumerable<string[]> asEnumerable = list.GroupBy(bom => bom.FlatComponent).Select(grouping => new string[] { grouping.Key, string.Join(", ", grouping.Select(bom => bom.Part)), string.Join(", ", grouping.Select(bom => bom.QtyPer)) });
string[][] asStringArray = asEnumerable.ToArray();
// For convenience add read-only property
public sealed class BOM
{
...
public string PartAndQuantity { get{return Part + ", " + QtyPer;} }
}
// Group by FlatComponent and then use string.Join:
var result = list.GroupBy (l => l.FlatComponent).Select(
g => new
{
Flat=g.Key,
Parts=string.Join(", ", g.Select (x => x.PartAndQuantity))
});
这将导致
Flat Parts
a "1, 2, 3, 4"
b "5, 6"
c "7, 8, 9, 0"
但是你可能想要
var result = list.GroupBy (l => l.FlatComponent).Select(
g => new
{
Flat=g.Key,
Parts=g.Select (x => x.PartAndQuantity).ToList()
});
我想不出用一个表达式来完成这一切的方法(并且仍然可以理解(,但这里有一些代码可以做你想做的:
[编辑:没有注意到你把零件和数量作为一个字符串,这改变了它:]
var groups = list.GroupBy(item => item.FlatComponent);
List<List<string>> result = new List<List<string>>();
foreach (var group in groups) {
var current = new List<string>();
current.Add(group.Key);
current.AddRange(group.Select(grp => string.Format("{0}, {1}", grp.Part, grp.QtyPer)));
result.Add(current.Distinct().ToList());
}