Develop Reference

Nested foreach loops with side effects for Entity Framework

I have problem with nested foreach loops because of following example:
var someList = new List<SimpleC>();
simpleA = database.SimpleA.ToList();
simpleB = database.SimpleB.ToList();
foreach (var a in simpleA)
{
foreach (var b in simpleB)
{
var c = new simpleC();
c.simpleAId = a.Id;
c.simpleAName = a.Name;
c.simpleBName = b.Name;
someList.Add(c);
}
}
return someList;
The problem: imagine first iteration it goes to first foreach loop then to second foreach loop it initiates new object, maps values and adds newly initiated object to new list, but when second iteration comes instead of going back to first foreach loop it continues with second foreach loop and it loops through second until it finishes, I understand that's how C# works, but I need side effect for it to continue to first foreach loop to get new values.

You would be much better served by not trying to iterate this manually, establishing a relationship and querying it as a join set of entities:
var results = database.SimpleA
.Join(database.SimpleB,
a => a.ID,
b => b.Post_ID, /
(a, b) => new { colA = a, colB = b })
.Select new SimpleA(){
Property1 = a.Col1,
Property2 = b.Col3,
Property4 = a.Col2
}).ToList();
This is only mostly functional as a starting point. You might need a left outer join instead.
Another option, if A and B have a fk constraint in the database, then you may use Navigation properties instead of a join.
If for whatever reason, your loop is required we can try and breakdown the issue:
foreach (var a in simpleA)
{
foreach (var b in simpleB) // There is no relationship here!
{
var c = new simpleC();
c.simpleAId = a.Id;
c.simpleAName = a.Name;
c.simpleBName = b.Name;
someList.Add(c);
}
}
You could try using the index, but that is very likely to cause issues.
Instead:
foreach (var a in simpleA)
{
var matchedB = simpleB.Where(x => x.Id == a.Id).FirstOrDefault();
var c = new simpleC();
c.simpleAId = a.Id;
c.simpleAName = a.Name;
c.simpleBName = matchedB.Name;
someList.Add(c);
}

I think, if I'm understanding your question, is that you don't want it to loop through in a nested fashion, but only loop once. To do that you'd do it like this.
for(int i = 0; i < simpleA.Count; i++)
{
var c = new simpleC();
c.simpleAId = simpleA[i].Name;
c.simpleAName = simpleA[i].Name;
c.simpleBName = simpleB[i].Name;
someList.Add(c);
}

C# How to make a list out of IEnumerable

I'm currently playing with TvDbSharper (https://github.com/HristoKolev/TvDbSharper) and i have a question about IEnumerable.
What i'm trying to do is get all the Id for a given series and then add the result in a listView.
This code gives me the first Id in the list:
const int SeriesId = 78804;
var tasks = new List<Task<TvDbResponse<BasicEpisode[]>>>();
var firstResponse = await client.Series.GetEpisodesAsync(SeriesId, 1);
for (int i = 2; i <= firstResponse.Links.Last; i++)
{
tasks.Add(client.Series.GetEpisodesAsync(SeriesId, i));
}
var results = await Task.WhenAll(tasks);
var episodes = firstResponse.Data.Concat(results.SelectMany(x => x.Data));
epsListview.View = View.Details;
epsListview.Columns.Add("Episode", 100);
string[] arr = new string[4];
ListViewItem itm;
arr[0] = episodes.First().Id.ToString();
itm = new ListViewItem(arr);
epsListview.Items.Add(itm);
but what i want is to make a new line in the epsListview for each id available.
I never used IEnumerable and i'm still very novice using c#, i've been stuck with this problem for over a week now. can anyone help me with this ?
Thanks!!

It looks like you're wanting to build an array of IDs from an IEnumerable of episodes, and add that array to a single ListViewItem. This should do that.
string[] arr = episodes.Select(episode => episode.Id.ToString()).ToArray()
ListViewItem itm = new ListViewItem(arr);
epsListview.Items.Add(itm);

Iterate through 2 lists of shapes within a single foreach C#

I have 2 lists of shapeIds from 2 seperate PowerPoint presentations, one from and original PowerPoint and another from an edited PowerPoint.
I now want to compare the items in these 2 lists ShapeId's to each other. For example I want to compare the colour and the font size etc.
I've tried a number of ways to do this and decided the best way to would be to iterate through each ShapeId in the 2 lists. Is there anyway I can iterate through each list within one foreach loop? Such as foreach (Microsoft.Office.Interop.PowerPoint.Slide slide item1 in list1, Microsoft.Office.Interop.PowerPoint.Slide slide item2 in list2)
My code is as fallows
Microsoft.Office.Interop.PowerPoint.CustomLayout customLayout = pptPresentationOriginal.SlideMaster.CustomLayouts[Microsoft.Office.Interop.PowerPoint.PpSlideLayout.ppLayoutText];
Microsoft.Office.Interop.PowerPoint.Slides Originalslides;
Microsoft.Office.Interop.PowerPoint.Slides EditedSlides;
Microsoft.Office.Interop.PowerPoint.Shape originalShp;
Microsoft.Office.Interop.PowerPoint.Shape editShp;
Originalslides = pptPresentationOriginal.Slides;
EditedSlides = pptPresentationEdit.Slides;
List<char> l = new List<char>();
List<char> l2 = new List<char>();
List<int> originalShapesListID = new List<int>();
List<int> editedShapesListID = new List<int>();
List<int> originalListID = new List<int>();
List<int> editedListID = new List<int>();
List<Microsoft.Office.Interop.PowerPoint.Shape> originalList = new List<Microsoft.Office.Interop.PowerPoint.Shape>();
List<Microsoft.Office.Interop.PowerPoint.Shape> editList = new List<Microsoft.Office.Interop.PowerPoint.Shape>();
Microsoft.Office.Interop.PowerPoint.Shape editedShpID;
Logic
String pps = "";
foreach (Microsoft.Office.Interop.PowerPoint.Slide slide in Originalslides)
{
foreach (Microsoft.Office.Interop.PowerPoint.Shape originalShape in slide.Shapes)
{
originalShp = originalShape;
if (originalShape.HasTextFrame == Microsoft.Office.Core.MsoTriState.msoTrue)
{
var textFrame = originalShape.TextFrame;
if (textFrame.HasText == Microsoft.Office.Core.MsoTriState.msoTrue)
{
var textRange = textFrame.TextRange;
pps += originalShape.TextFrame.TextRange.Text;
foreach (char word in pps)
{
l.Add(word);
Debug.WriteLine(word);
}
}
}
originalShapesListID.Add(originalShape.Id);
originalShapeID = originalShape.Id;
originalList.Add(originalShape);
}
originalListID.Add(slide.SlideID);
}
foreach (Microsoft.Office.Interop.PowerPoint.Slide slide in EditedSlides)
{
foreach (Microsoft.Office.Interop.PowerPoint.Shape editShape in slide.Shapes)
{
editShp = editShape;
if (editShape.HasTextFrame == Microsoft.Office.Core.MsoTriState.msoTrue)
{
var textFrame = editShape.TextFrame;
if (textFrame.HasText == Microsoft.Office.Core.MsoTriState.msoTrue)
{
var textRange = textFrame.TextRange;
pps += editShape.TextFrame.TextRange.Text;
foreach (char word in pps)
{
l.Add(word);
Debug.WriteLine(word);
}
}
}
editedShapesListID.Add(editShape.Id);
editedShapeID = editShape.Id;
editList.Add(editShape);
}
editedListID.Add(slide.SlideID);
}
Here is where I want to go through the 2 lists and compare each item (ShapeId) in each list. I want to do something like this.
foreach (Microsoft.Office.Interop.PowerPoint.Shape editShape in editedShapesListID, Microsoft.Office.Interop.PowerPoint.Shape original in originalShapesListID )
{
if (originalShapeID == editedShapeID)
{
if (original.TextFrame.TextRange.Font.Color.RGB != editShape.TextFrame.TextRange.Font.Color.RGB)
{
originalShp.TextFrame2.TextRange.Font.StrikeThrough.ToString();
}
}
}

Since you want to match the items on a specific key Id. A good option would be to use a join. Join will build a hash-table for the inner collection which has O(1) lookup.
var q = from original in originalShapes
join editedTmp in editedShapes on original.Id equals editedTmp.Id into g
from edited in g.DefaultIfEmpty()
select new
{
original,
edited
};
foreach(var item in q)
{
//item.edited might be null if no matching original was found.
if (item.edited == null || item.original.TextFrame.TextRange.Font.Color.RGB != item.edited.TextFrame.TextRange.Font.Color.RGB)
{
item.original.TextFrame2.TextRange.Font.StrikeThrough.ToString();
}
}

using (var originalEnumerator = originalShapesListID.GetEnumerator())
foreach (var editShape in editedShapesListID)
{
if (!originalEnumerator.MoveNext()) break;
var original = originalEnumerator.Current;
...
}

You can use 2 Dictionary instead of 4 Lists and then using Join.
Here is an example with int and string (replace string with Microsoft.Office.Interop.PowerPoint.Shape for your issue):
Dictionary<int, string> loDicOriginal = new Dictionary<int, string>();
Dictionary<int, string> loDicEdit = new Dictionary<int, string>();
loDicOriginal.Add(1, "int 1 list 1");
loDicOriginal.Add(2, "int 2 list 1");
loDicOriginal.Add(3, "int 3 list 1");
loDicEdit.Add(1, "int 1 list 2");
loDicEdit.Add(3, "int 3 list 2");
var loQuery = loDicOriginal.Join(loDicEdit,
dicOrg => dicOrg.Key,
dicEdit => dicEdit.Key,
(entryOrg, entryEdit) => new { Original = entryOrg, Edit = entryEdit });
foreach (var loOut in loQuery)
{
System.Diagnostics.Debug.WriteLine("{0}->{1} | {2}->{3}", loOut.Original.Key, loOut.Original.Value, loOut.Edit.Key, loOut.Edit.Value);
}
Output is:
1->int 1 list 1 | 1->int 1 list 2
3->int 3 list 1 | 3->int 3 list 2
I hope it is clear what I mean.

How to add calculated fields to SQL list

I am tracking fuel for trucks.
List<FuelLightTruckDataSource> data = new List<FuelLightTruckDataSource>();
using (SystemContext ctx = new SystemContext())
{
List<FuelLightTruckDataSource> dataTransfers
= ctx.FuelTransfer
.Where(tr => DbFunctions.TruncateTime(tr.Date) >= from.Date && DbFunctions.TruncateTime(tr.Date) <= to.Date
//&& tr.ToAsset.AssignedToEmployee.Manager
&& tr.ToAsset.AssignedToEmployee != null
&& tr.ToAsset.AssetType.Code == "L"
&& tr.Volume != null)
//&& (tr.FuelProductType.FuelProductClass.Code == "GAS" || tr.FuelProductType.FuelProductClass.Code == "DSL"))
.GroupBy(tr => new { tr.ToAsset, tr.Date, tr.FuelTankLog.FuelProductType.FuelProductClass, tr.FuelTankLog.FuelCard.FuelVendor,tr.Volume, tr.ToAssetOdometer })
.Select(g => new FuelLightTruckDataSource()
{
Asset = g.FirstOrDefault().ToAsset,
Employee = g.FirstOrDefault().ToAsset.AssignedToEmployee,
ProductClass = g.FirstOrDefault().FuelTankLog.FuelProductType.FuelProductClass,
Vendor = g.FirstOrDefault().FuelTankLog.FuelCard.FuelVendor,
FillSource = FuelFillSource.Transfer,
Source = "Slip Tank",
City = "",
Volume = g.FirstOrDefault().Volume.Value,
Distance = g.FirstOrDefault().ToAssetOdometer,
Date = g.FirstOrDefault().Date,
})
.ToList();
After my query, I need to calculate the consumption rate and distance traveled. "Result" will be a collection of entries including "consumptionRate" and "Distance" and it matches the query above.
// Get consumption rate data for each asset
foreach (int assetId in assetIds)
{
FuelConsumptionRateQueryResult result = FuelConsumptionRateQueryService.Get(assetId, from, to, AssetCounterType.Odometer);
result.Entries.ToList();
}
My question is how do I get the result of my foreach loop and add them to my previous query/list, so they can show up in the report?

Your issue seems to be due to the fact that you're declaring result as a new variable at each iteration of the foreach loop, causing result to be overwritten. Additionally, result isn't in scope once you finish with the foreach loop.
Instead, you probably want something closer to:
var allResults = new List<T>; //where T is whatever object type this is (FuelConsumptionRateQueryResult?)
foreach (int assetId in assetIds)
{
//this is a new variable at each iteration of the loop
FuelConsumptionRateQueryResult result = FuelConsumptionRateQueryService.Get(assetId, from, to, AssetCounterType.Odometer);
allResults.Add(result); //add the current result to your list (outside the scope of this loop)
}
Basically, declare your variable outside of the loop and Add each individual result to the allResults list.

Create the additional data by a LINQ statement and concatenate both lists:
var results = assetIds.Select(id => FuelConsumptionRateQueryService
.Get(id, from, to, AssetCounterType.Odometer);
dataTransfers = dataTransfers.Concat(results);

dictionary of lists in c#(cant seem to get my lists)

Here i used linq to filter my result in an array and pass into a list and from that list into a dictionary as you can see below
//array is a multidimensional array with string data in it
var datumn = array;
var list = new List<string>();
var stringcounts = new Dictionary<int,List<string>>();
var listtemp = new List<string>();
//linq
var arrayresult = from string a in datumn where a != "FREE" select a;
//adding result from arrayresult to list
foreach (var listing in arrayresult)
{
list.Add(listing);
}
//using linq again i filter my list then add to dictionary
for (int count = 3; count > 0; count-- )
{
var duplicateItems = from x in list
group x by x into grouped
where grouped.Count() == count
select grouped.Key;
foreach (var replace in duplicateItems)
{
listtemp.Add(replace.ToString());
}
stringcounts.Add(count, lists);
//clearing the list to avoid duplicating data in my dictionary
listtemp.Clear();
}
for (int key = stringcounts.Count; key > 0; --key)
{
var holding = stringcounts[key];
foreach (var li in holding)
{
MessageBox.Show(li.ToString());
//just view what i have to check if the data is correct
}
}
`
the program skips iterator over of the lists and ends can some one help with this
and i have tried everything including linq and other collections like hashtable
and maps but nothing works and it is not a console application

This line is wrong:
var dict = new Dictionary<int, List<string>>();
Remove the ";".
Result:
indigo silver violet purple green pink red brown yellow
Edit: full code for comparison:
var dict = new Dictionary<int, List<string>>()
{
{1, new List<string>{"red", "brown", "yellow"}},
{2, new List<string>{"purple", "green", "pink"}},
{3, new List<string>{"indigo", "silver", "violet"}}
};
// now i want to get my values from the lists in the dictionary
for (int count = 3; count > 0; count--)
{
var l = dict[count];
foreach (var li in l)
{
li.Dump();
}
}

foreach (var item in dict)
{
var list = item.Value;
foreach (var str in list)
{
MessageBox.Show(str);
}
}

The listtemp.Clear() is a bad syntax so therefore it should be removed and the listtemp should be declared in the for loop therefore removing redundancy and the initial problem