将LINQ C＃转换为VB.NET

Question

我正在处理这个怪物：

public static IEnumerable<Warp> GetWarps(IEnumerable<Point> sourcePoints, IEnumerable<Point> destPoints, IEnumerable<Triangle> destTriangles)
{
    // build lists of source and destination landmark points
    var sourceList = sourcePoints.ToList();
    var destList = destPoints.ToList();

    // find all three triangle points in the list of destination landmark points
    var indices = from t in destTriangles
                  let p1 = destPoints.First(p => Math.Abs(p.X - t.P1.X) < 1 && Math.Abs(p.Y - t.P1.Y) < 1)
                  let p2 = destPoints.First(p => Math.Abs(p.X - t.P2.X) < 1 && Math.Abs(p.Y - t.P2.Y) < 1)
                  let p3 = destPoints.First(p => Math.Abs(p.X - t.P3.X) < 1 && Math.Abs(p.Y - t.P3.Y) < 1)
                  select new {
                      X1 = destList.IndexOf(p1),
                      X2 = destList.IndexOf(p2),
                      X3 = destList.IndexOf(p3)
                  };

    // return enumeration of warps from source to destination triangles
    return from x in indices
           select new Warp(
               new Triangle(sourceList[x.X1], sourceList[x.X2], sourceList[x.X3]),
               new Triangle(destList[x.X1], destList[x.X2], destList[x.X3]));
}

我已经尝试了很多，但我没有经验来处理语法和陷阱。

我自己的方法都失败了，我不知道我是否正朝着正确的方向前进：

 Function GetWarps(ByVal sourcePoints As IEnumerable(Of Point), ByVal destPoints As IEnumerable(Of Point), ByVal destTriangles As IEnumerable(Of Triangle)) As IEnumerable(Of Warp)

    Dim sourceList = sourcePoints.ToList()
    Dim destList = destPoints.ToList()

    Dim p1 As Triangle
    Dim p2 As Triangle
    Dim p3 As Triangle

    Dim indices = From t In destTriangles 
        p1 = destPoints.First(Function(p) Math.Abs(p.X - t.P1.X) < 1 AndAlso Math.Abs(p.Y - t.P1.Y) < 1) 
        p2 = destPoints.First(Function(p) Math.Abs(p.X - t.P2.X) < 1 AndAlso Math.Abs(p.Y - t.P2.Y) < 1) 
        p3 = destPoints.First(Function(p) Math.Abs(p.X - t.P3.X) < 1 AndAlso Math.Abs(p.Y - t.P3.Y) < 1) Select
     (
            .X1 = destList.IndexOf(p1), Key,
            .X2 = destList.IndexOf(p2), Key,
            .X3 = destList.IndexOf(p3), Key,
    )
    Return From x In indices Select New Warp(New Triangle(sourceList(x.X1), sourceList(x.X2), sourceList(x.X3)), New Triangle(destList(x.X1), destList(x.X2), destList(x.X3)))

End Function

谁能告诉我如何正确地做到这一点？

非常感谢你！！

Answer 1

我知道了！！ :-)

Public Function GetWarps(ByVal sourcePoints As IEnumerable(Of Point), ByVal destPoints As IEnumerable(Of Point), ByVal destTriangles As IEnumerable(Of Triangle)) As IEnumerable(Of Warp)
        ' build lists of source and destination landmark points
        Dim sourceList = sourcePoints.ToList()
        Dim destList = destPoints.ToList()

        ' find all three triangle points in the list of destination landmark points
        Dim indices = From t In destTriangles _
                      Let p1 = destPoints.First(Function(p) Math.Abs(p.X - t.P1.X) < 1 AndAlso Math.Abs(p.Y - t.P1.Y) < 1) Let p2 = destPoints.First(Function(p) Math.Abs(p.X - t.P2.X) < 1 AndAlso Math.Abs(p.Y - t.P2.Y) < 1) Let p3 = destPoints.First(Function(p) Math.Abs(p.X - t.P3.X) < 1 AndAlso Math.Abs(p.Y - t.P3.Y) < 1) _
                      Select New With {Key .X1 = destList.IndexOf(p1), Key .X2 = destList.IndexOf(p2), Key .X3 = destList.IndexOf(p3)}

        ' return enumeration of warps from source to destination triangles
        Return From x In indices _
               Select New Warp(New Triangle(sourceList(x.X1), sourceList(x.X2), sourceList(x.X3)), New Triangle(destList(x.X1), destList(x.X2), destList(x.X3)))
End Function

Answer 2

试试这个

Public Shared Function GetWarps(ByVal sourcePoints As IEnumerable(Of Point), ByVal destPoints As IEnumerable(Of Point), ByVal destTriangles As IEnumerable(Of Triangle)) As IEnumerable(Of Warp)
    Dim sourceList = sourcePoints.ToList()
    Dim destList = destPoints.ToList()
    Dim indices = From t In destTriangles Let p1 = destPoints.First(Function(p) Math.Abs(p.X - t.P1.X) < 1 AndAlso Math.Abs(p.Y - t.P1.Y) < 1) Let p2 = destPoints.First(Function(p) Math.Abs(p.X - t.P2.X) < 1 AndAlso Math.Abs(p.Y - t.P2.Y) < 1) Let p3 = destPoints.First(Function(p) Math.Abs(p.X - t.P3.X) < 1 AndAlso Math.Abs(p.Y - t.P3.Y) < 1) Select New With {Key
        .X1 = destList.IndexOf(p1), Key
        .X2 = destList.IndexOf(p2), Key
        .X3 = destList.IndexOf(p3)
    }
    Return From x In indices Select New Warp(New Triangle(sourceList(x.X1), sourceList(x.X2), sourceList(x.X3)), New Triangle(destList(x.X1), destList(x.X2), destList(x.X3)))
End Function