Question

请查看所需内容的粗略代码片段。类A是外部类，它有三个类型B的内部列表。

public class A
{
    public List<B> var1;
    public List<B> var2;
    public List<B> var3;
    int x;
    int y;
}

public class B
{
    public string strA;
    public string strB;
    public string strC;
}

// This is the new class which i want  as output      
public class C
{
    public string strC1;
    public string strC2;
    public string strC3;
    public int x;
    public int y;
    public bool direction;
}

List<A> ListA = SomeClass.GetData( );
List<B>  ListB= new List<B>();
List<C> ListC = new List<C>();

foreach(A myA in ListA)
{
    ListB = myA.var1;
    foreach(B mydata1 in ListB)
    {
    C var = new C();
    var.strC1 = mydata1.strA;
    var.strC2 = mydata1.strB;
    var.strC3 = mydata1.strC;
    var.x = myA.x;
    var.y = myA.y;
    var.direction = true; //if input it is true
    ListC.Add(var);

    }

    ListB = myA.var2;
    foreach(B mydata1 in ListB)
    {
    C var = new C();
    var.strC1 = mydata1.strA;
    var.strC2 = mydata1.strB;
    var.strC3 = mydata1.strC;
    var.x = myA.x;
    var.y = myA.y;
    var.direction = true; //if input it is true
    ListC.Add(var);

    }

    ListC = myA.var3;
    foreach(B mydata1 in ListB)
    {
    C var = new C();
    var.strC1 = mydata1.strA;
    var.strC2 = mydata1.strB;
    var.strC3 = mydata1.strC;
    var.x = myA.x;
    var.y = myA.y;
    var.direction = false; //if input it is true
    ListC.Add(var);

    }
}

var grpList = ListC.GroupBy(p => p.strC);

我的输出是ListC，它由内部类B和外部类A的元素组成，最终输出被分组。

Answer 1

编辑回答：对于扁平目标类C

public class C
{
    public string strC1;
    public string strC2;
    public string strC3;
    public int x;
    public int y;
    public bool direction;
}

只需使用SelectMany展平方法并将其合并几次......

var C1 = A1.SelectMany(p => p.var1, (p,q) => new C(){
    strC1 = q.strA,
    strC2 = q.strB,
    strC3 = q.strC,
    x = p.x,
    y = p.y,
    direction = true
    }
  ).Union(
    A1.SelectMany(p => p.var2, (p,q) => new C(){
    strC1 = q.strA,
    strC2 = q.strB,
    strC3 = q.strC,
    x = p.x,
    y = p.y,
    direction = true
    })
  ).Union(
    A1.SelectMany(p => p.var3, (p,q) => new C(){
    strC1 = q.strA,
    strC2 = q.strB,
    strC3 = q.strC,
    x = p.x,
    y = p.y,
    direction = false
    })
  ).ToList();

edit2：刚刚意识到我重复了3次以上相同的功能。更简洁的写作方式是：

var fn1 = new Func<A, B, C>( (p,q) => new C(){
    strC1 = q.strA,
    strC2 = q.strB,
    strC3 = q.strC,
    x = p.x,
    y = p.y,
    direction = !p.var3.Contains(q)
    });

var C1 = A1.SelectMany(p => p.var1, fn1
  ).Union(
    A1.SelectMany(p => p.var2, fn1)
  ).Union(
    A1.SelectMany(p => p.var3, fn1)
  ).ToList();

edit3 - 来自var3列表的上述示例中的方向现为false

下面有一篇文章解释了SelectMany ...... http://dotnet.dzone.com/news/selectmany-probably-the-most-p

LINQ从外部和内部列表的元素创建新列表

1 个答案: