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Using Linq to determine if there is more than 2 distinct items in a class

I have a class that contains a list of another class which has a property that I want to check if it has more than one distinct value.
e.g
public class BasketModel
{
public BasketModel()
{
BasketOrderLines = new List<BasketOrderLine>();
}
.
.
.
public class BasketOrderLine
{
public int OrderLineId { get; set; }
public string ImageUrl { get; set; }
public string ProductType { get; set; }
.
.
Given a basket model object I want to find out if there are more than one distinct value in the ProductType.
e.g If all Product Types are "A" then that would be false, if 3 products are of type "A" and one is of type "B" then this would be true.
Cheers
Macca

Your title: "more than two distinct", your question body: "more than one distinct"
If the title is a typo:
bool notDistinctTypes = theBasket.BasketOrderLine
.Select(o => o.ProductType)
.Distinct()
.Skip(1)
.Any();
This doesn't need to enumerate all items to find out if there is more than one ProductType.

// Does this basket contains three or more types
public bool HasSeveralTypes(BasketModel basket)
{
if (basket == null)
return false;
int differentTypes = basket.BasketOrderLines
.Select(l => l.ProductType)
.Distinct()
.Count();
return (differentTypes > 2);
}

Something like this :
Public bool CheckDistinct (){
var res = basketOrderLines.Select(o => o.ProductType).Distinct ().Count ();
return res > 1;
}

There are a few ways to do this, here's one:
public class BasketModel
{
public BasketModel()
{
BasketOrderLines = new List<BasketOrderLine>();
}
public bool HasMulitpleDistinctProducts
{
get
{
if (!BasketOrderLines.Any())
{
return true; // or false?
}
return BasketOrderLines.Select(b => b.ProductType).Distinct().Count() > 1;
}
}
}

Here is a type extension you can call directly from your list. The pros of this code is to be adaptable to any type implementing IEquals and not only string + kick to use from your code.
The code :
public static class Tools
{
public static bool fDistinctProductType(this List<BasketOrderLine> lstToAnalyse)
{
BasketOrderLine ProductTypeA = lstToAnalyse.FirstOrDefault();
if (ProductTypeA == null) // It's null when lstToAnalyse is empty
return false;
BasketOrderLine ProductTypeB = lstToAnalyse.Where(b => b.ProductType.Equals(ProductTypeA.ProductType)).FirstOrDefault();
if (ProductTypeB == null) // It's null when it doesn't exists a distinct ProductType
return false;
return true;
}
}
How to call:
List<BasketOrderLine> lst = new List<BasketOrderLine>();
// Add element to list
if (lst.fDistinctProductType())
{
// DO Something
}

Serialize list of objects

I need to serialize/deserialize some XML code and part of it looks like next example:
<CoordGeom>
<Curve rot="cw" chord="830.754618036885" crvType="arc" delta="72.796763873948" dirEnd="283.177582669379" dirStart="355.974346543327" external="169.661846548051" length="889.38025007632" midOrd="136.562611151675" radius="699.999999998612" tangent="516.053996536113">
<Start>4897794.2800513292 6491234.9390137056</Start>
<Center>4897096.0071489429 6491185.7968343571</Center>
<End>4897255.5861026254 6491867.3645547926</End>
<PI>4897758.0514541129 6491749.7197593488</PI>
</Curve>
<Spiral length="109.418078418008" radiusEnd="INF" radiusStart="699.999999999025" rot="cw" spiType="clothoid" theta="4.477995782709" totalY="2.849307921907" totalX="109.351261203955" tanLong="72.968738862921" tanShort="36.493923980983">
<Start>4897255.5861026254 6491867.3645547936</Start>
<PI>4897220.0531303799 6491875.6840722272</PI>
<End>4897147.9238984985 6491886.7208634559</End>
</Spiral>
<Spiral length="153.185309785019" radiusEnd="499.99999999993" radiusStart="INF" rot="ccw" spiType="clothoid" theta="8.776871734087" totalY="7.808812331497" totalX="152.826239431476" tanLong="102.249348442205" tanShort="51.176160975293">
<Start>4897147.9238985004 6491886.7208634559</Start>
<PI>4897046.8509311257 6491902.186455016</PI>
<End>4896998.0370401107 6491917.5553683294</End>
</Spiral>
<Curve rot="ccw" chord="936.510896488672" crvType="arc" delta="138.94725576785" dirEnd="66.423714388543" dirStart="287.476458620693" external="925.970149937768" length="1212.543549877849" midOrd="324.680762068264" radius="499.999999999181" tangent="1335.436583485725">
<Start>4896998.0370401107 6491917.5553683294</Start>
<Center>4897148.1939981515 6492394.4755796343</Center>
<End>4896948.2091376046 6492852.7397562303</End>
<PI>4895724.243644949 6492318.6055583945</PI>
</Curve>
</CoordGeom>
I've generated automatically classes using xsd.exe. Part of generated code looks like this:
public partial class CoordGeom
{
private List<object> _items;
private List<Feature> _feature;
private string _desc;
private string _name;
private stateType _state;
private string _oID;
public CoordGeom()
{
_feature = new List<Feature>();
_items = new List<object>();
}
[XmlElementAttribute("Chain", typeof(Chain))]
[XmlElementAttribute("Curve", typeof(Curve))]
[XmlElementAttribute("IrregularLine", typeof(IrregularLine))]
[XmlElementAttribute("Line", typeof(Line))]
[XmlElementAttribute("Spiral", typeof(Spiral))]
public List<object> Items
{
get { return this._items; }
set { this._items = value; }
}
[XmlElement("Feature")]
public List<Feature> Feature { get; set; }
[XmlAttribute()]
public string desc { get; set; }
[XmlAttribute()]
public string name { get; set; }
[XmlAttribute()]
public stateType state { get; set; }
[System.Xml.Serialization.XmlAttributeAttribute()]
public string oID
{
get{ return this._oID; }
set{ this._oID = value; }
}
}
And my code for deserialization look like this:
XmlSerializer mySerializer = new XmlSerializer(typeof(LandXML), new XmlRootAttribute(""));
TextReader myFileStream = new StreamReader("myFile.xml");
LandXML myObject = (LandXML)mySerializer.Deserialize(myFileStream);
var coordGeomItems = myObject.Alignments.Alignment[0].CoordGeom;
My problem is that, when I deserialize file, it is deserialized as list of items of type {LandXML.Curve}, {LandXML.Spiral} etc. and I don't know how to access their properties. It would be great if I can do this directly. Here is a screenshot:
EDIT 1
Here is inital screen
then I have items:
When I unfold this
And this is at the top layer of object - it has some InnerXml, InnerText... If I want to achieve CoordGeom, there is a lot object.Item(i).ChildNodes.Item(j).ChildNodes...
And all of that is because in some lines, lists of objects are made like List as for CoordGeom

Because there are multiple allowed types, the Items collection is typed as object. The simplest approach is to enumerate and cast each item:
foreach(var item in coordGeomItems.Items)
{
var curve = item as Curve;
if (curve != null)
{
// access curve properties here
}
var spiral = item as Spiral
if (spiral != null)
{
// access spiral properties here
}
// ...
}

You could build up a list of Curves and Spirals and access them using properties with custom getters:
class CoordGeom
{
public List<object> Items;
List<Curve> _curves;
public List<Curve> Curves
{
get
{
return _curves ?? (_curves = Items
.Where(item => item is Curve).Select(curve => (Curve)curve).ToList());
}
}
}
The null coalescing operator (??) will cause the Curves property to set and return the value of _curves as a list of curves if _curves is null. This basically causes it to initialize the list on the first get and on all subsequent gets it will return the already initialized list.

As you cannot change the generated class nor the XML.The best possible approach would be to write an extension method.
public static List<Curve> GetCurves(this CoordGeom cg)
{
return cg.Items.OfType<Curve>().ToList();
}
public static List<Spiral> GetSpirals(this CoordGeom cg)
{
return cg.Items.OfType<Spiral>().ToList();
}
Once you do this, you can get items like this
var coordGeomItems = myObject.Alignments.Alignment[0].CoordGeom;
var curves = coordGeomItems.GetCurves();
var spirals = coordGeomItems.GetSpirals();

C# enum in public variable .NET

For my program, I created a new class called FinishedPiece with a number of public variables available to my main program. For example:
class FinishedPiece
{
private double _PieceLength;
public double PieceLength
{
get { return _PieceLength; }
set { _PieceLength = value; }
}
}
This all works fine, because then I can declare a new FinishedPiece and add properties:
FinishedPiece piece = new FinishedPiece();
piece.PieceLength = 48.25;
My question is, how do the same with an enum? If I do
public enum Cut
{
Angle = 0,
Straight = 1,
AngleThenStraight = 2,
StraightThenAngle = 3
};
then I'd like to change it something like this: piece.Cut = Cut.Angle; but I can only change it by declaring a new FinishedPiece.Cut object:
FinishedPiece.Cut cut = new FinishedPiece.Cut();
cut = FinishedPiece.Cut.Angle;
How do I make an enum available inside a variable so I can do piece.Cut = Cut.Angle? To me it would make sense to do something like this, but it doesn't appear to work.
public int Cut
{
get { return _Cut; }
set { _Cut = value; }
}
private enum _Cut
{
Angle = 0,
Straight = 1,
AngleThenStraight = 2,
StraightThenAngle = 3
};
Thanks in advance! Let me know if my question is unclear and I'll try to help as best as I can.

How do I make an enum available inside a variable so I can do
piece.Cut = Cut.Angle?
Just define another property of type Cut in your class like:
public Cut Cut { get; set; }
Then you can do:
FinishedPiece piece = new FinishedPiece();
piece.PieceLength = 48.25;
piece.Cut = Cut.Angle; //like this
So your class would like like:
class FinishedPiece
{
private double _PieceLength;
public double PieceLength
{
get { return _PieceLength; }
set { _PieceLength = value; }
}
public Cut Cut { get; set; }
}
Consider using Auto-Implemented properties, if you have only simple set and get

Like this:
class FinishedPiece
{
private double _PieceLength;
public double PieceLength
{
get { return _PieceLength; }
set { _PieceLength = value; }
}
private Cut _Cut;
public Cut Cut
{
get { return _Cut; }
set { _Cut = value; }
}
}
public enum Cut
{
Angle = 0,
Straight = 1,
AngleThenStraight = 2,
StraightThenAngle = 3
};
Then you can do:
var piece = new FinishedPiece();
piece.Cut = Cut.AngleThenStraight;

You can try this:
private enum Cut
{
//if you dont want to use any of these values as defaults
//just add another value and in your class private member
//assign it like for example a value called None
Angle = 0,
Straight = 1,
AngleThenStraight = 2,
StraightThenAngle = 3
};
public class FinishedPiece
{
//give it a default,if like stated in the enum you dont want
//any of those values create a None and place it here as default.
private Cut cutObj = Cut.Angle;
public Cut CutObj
{
get { return cutObj; }
set { cutObj = value; }
}
}
Then in your calling code...
FinishedPiece piece = new FinishedPiece();
//if you dont want the default change it...
piece.CutObj = Cut.Straight;

how can i get an access to the elements of array in the class

I have a problem which I don't know how to solve. I have a class. This class has two arrays. I would like to get access via properties. How can I do it? I tried to use indexers, but it is possible if I have only one array. Here what I want to do:
public class pointCollection
{
string[] myX;
double[] myY;
int maxArray;
int i;
public pointCollection(int maxArray)
{
this.maxArray = maxArray;
this.myX = new string[maxArray];
this.myY = new double[maxArray];
}
public string X //It is just simple variable
{
set { this.myX[i] = value; }
get { return this.myX[i]; }
}
public double Y //it's too
{
set { this.myY[i] = value; }
get { return this.myY[i]; }
}
}
With this code, my X and Y are only simple variables, but not arrays.
If I use indexers, I get access only to one array:
public string this[int i]
{
set { this.myX[i] = value; }
get { return this.myX[i]; }
}
But how can I get access to second array?
Or I can't use property in this case? And I need only use:
public string[] myX;
public double[] myY;

An example with Tuples.
public class pointCollection
{
Tuple<String,Double>[] myPoints;
int maxArray;
int i;
public pointCollection(int maxArray)
{
this.maxArray = maxArray;
this.myPoints = new Tuple<String,Double>[maxArray];
}
public Tuple<String,Double> this[int i]
{
set { this.myPoints[i] = value; }
get { return this.myPoints[i]; }
}
}
And to access the points you do...
pointCollection pc = new pointCollection(10);
// add some data
String x = pc[4].Item1; // the first entry in a tuple is accessed via the Item1 property
Double y = pc[4].Item2; // the second entry in a tuple is accessed via the Item2 property

If I got it right, you need some kind or read/write-only wrapper for arrays to be exposed as properties.
public class ReadWriteOnlyArray<T>{
private T[] _array;
public ReadWriteOnlyArray(T[] array){
this._array = array;
}
public T this[int i]{
get { return _array[i]; }
set { _array[i] = value; }
}
}
public class pointCollection
{
string[] myX;
double[] myY;
int maxArray;
public ReadWriteOnlyArray<string> X {get; private set;}
public ReadWriteOnlyArray<double> Y {get; private set;}
public pointCollection(int maxArray)
{
this.maxArray = maxArray;
this.myX = new string[maxArray];
this.myY = new double[maxArray];
X = new ReadWriteOnlyArray<string>(myX);
Y = new ReadWriteOnlyArray<double>(myY);
}
}
and usage
var c = new pointCollection(100);
c.X[10] = "hello world";
c.Y[20] = c.Y[30] + c.Y[40];

The closest you'll come without either changing your data structure or moving to methods is to make a property that returns each array, much like you did in your first code block, except without the [i].
Then, you do var x = instanceOfPointCollection.MyX[someI]; for example.

Replacing/changing a blank or null string value in C#

I've got something like this in my property/accessor method of a constructor for my program.
using System;
namespace BusinessTrips
{
public class Expense
{
private string paymentMethod;
public Expense()
{
}
public Expense(string pmtMthd)
{
paymentMethod = pmtMthd;
}
//This is where things get problematic
public string PaymentMethod
{
get
{
return paymentMethod;
}
set
{
if (string.IsNullOrWhiteSpace(" "))
paymentMethod = "~~unspecified~~";
else paymentMethod = value;
}
}
}
}
When a new attribute is entered, for PaymentMethod, which is null or a space, this clearly does not work. Any ideas?

do you perhaps just need to replace string.IsNullOrWhiteSpace(" ") with string.IsNullOrWhiteSpace(value) ?
From your posted code, you need to call:
this.PaymentMethod = pmtMthd;
instead of
paymentMethod = pmtMthd;
The capital p will use your property instead of the string directly. This is why it's a good idea to use this. when accessing class variables. In this case, it's the capital not the this. that makes the difference, but I'd get into the habit of using this.

Jean-Barnard Pellerin's answer is correct.
But here is the full code, which I tested in LinqPad to show that it works.
public class Foo {
private string _paymentMethod = "~~unspecified~~";
public string PaymentMethod
{
get
{
return _paymentMethod;
}
set
{
if (string.IsNullOrWhiteSpace(value))
_paymentMethod = "~~unspecified~~";
else _paymentMethod = value;
}
}
}
With a main of:
void Main()
{
var f = new Foo();
f.PaymentMethod = "";
Console.WriteLine(f.PaymentMethod);
f.PaymentMethod = " ";
Console.WriteLine(f.PaymentMethod);
f.PaymentMethod = "FooBar";
Console.WriteLine(f.PaymentMethod);
}
Output from console:
~~unspecified~~
~~unspecified~~
FooBar