Linq from multiple Foreach

Question

How would I convert the following multiple foreach to LINQ?

    foreach (var resourceOne in resourceList)
    {
        string s = (string)resourceOne;
        foreach (Control c in gridBtn.Children)
        {
            if (c.GetType() == typeof(ToggleButton))
            {
                int TagPlusOne = Convert.ToInt32(c.Tag) + 1;
                string PaddedResult = TagPlusOne.ToString().PadLeft(3, '0');
                if (PaddedResult == s)
                {
                    ((ToggleButton)c).BorderBrush = Brushes.Red;
                    ((ToggleButton)c).BorderThickness = new Thickness(3, 3, 3, 3);
                }
            }
        }
    }

score 2 · Answer 1 · edited Mar 20 '20 at 10:37

You can't really, however you could simply it by using Where and OfType:

foreach (var in gridBtn.Children.OfType<ToggleButton>)
{
    int TagPlusOne = Convert.ToInt32(c.Tag) + 1;
    string PaddedResult = TagPlusOne.ToString().PadLeft(3, '0');
    foreach (var resourceOne in resourceList.Where(x => x == PaddedResult))
    {
        c.BorderBrush = Brushes.Red;
        c.BorderThickness = new Thickness(3, 3, 3, 3);
    }
}

Disclaimer: totally untested.

score 2 · Answer 2 · answered Aug 28 '18 at 01:47

2

IEnumerable<ToggleButton> query =
  from c in gridBtn.Children
  where c.GetType() == typeof(ToggleButton)
  let tagPlusOne = Convert.ToInt32(c.Tag) + 1
  let paddedResult = tagPlusOne.ToString().PadLeft(3, '0')
  join s in resourceList.Cast<string>() on paddedResult equals s
  select c;


foreach(ToggleButton button in query)
{
  button.BorderBrush = Brushes.Red;
  button.BorderThickness = new Thickness(3, 3, 3, 3);
}

answered Aug 28 '18 at 01:47

Amy B

108,202
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Upvoted as its more inline with the spirit of the question – TheGeneral Aug 28 '18 at 01:53
Ok this is actually way better – MetaColon Aug 28 '18 at 02:01
any idea on following error : Could not find any implementation of the query pattern for source type "UIElement Collection" .Where is not found . gridBtn Actually its my wpf Grid control – Loh ZhiCheng Aug 28 '18 at 03:21
You could call OfType if gridBtn.Children does not implement IEnumerable – Amy B Aug 28 '18 at 14:42

score 0 · Answer 3 · answered Aug 28 '18 at 02:00

You could do something like this (I couldn't test it though, as I don't have your environment):

gridBtn.Children.Where(c =>
        c.GetType() == typeof(ToggleButton) && resourceList.Any(resourceOne =>
            (string) resourceOne ==
            Convert.ToInt32(c.Tag) + 1.ToString().PadLeft(3, '0')))
    .ToList().ForEach(c =>
    {
        ((ToggleButton) c).BorderBrush = Brushes.Red;
        ((ToggleButton) c).BorderThickness = new Thickness(3, 3, 3, 3);
    });

Saeb Amini · Accepted Answer · 2018-08-28T02:18:30.947

0

In the end, you'll need a foreach or similar to set the properties on your buttons as LINQ is for querying your data (generally side-effect free), not mutating them. However, you can use LINQ to simplify finding the buttons you want to edit. e.g. your code could boil down to:

var targetButtons = gridBtn
    .Children
    .OfType<ToggleButton>()
    .Where(tb => resourceList.OfType<string>().Contains($"{Convert.ToInt32(tb.Tag) + 1}:D3"));

foreach(var btn in targetButtons)
{
    btn.BorderBrush = Brushes.Red;
    btn.BorderThickness = new Thickness(3, 3, 3, 3);
}

Which can be further tweaked/optimized/refactored. Note I've replaced PadLeft(3, '0') with the D3 standard number format string which does the same thing.

edited Aug 28 '18 at 02:18

answered Aug 28 '18 at 02:12

Saeb Amini

23,054
9
78
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somehow $"{Convert.ToInt32(tb.Tag) + 1}:D3") does not work for my WPF . due to $ not recognized . i use my original code padleft and it works . thanks – Loh ZhiCheng Aug 28 '18 at 03:24
@LohZhiCheng `$"..."` is an [interpolated string](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/tokens/interpolated) which is similar to `string.Format`. It's a C# 6 feature. If it's not available then you're probably using an older version of C#. – Saeb Amini Aug 28 '18 at 03:26

Vahid Asbaghi · Answer 5 · 2018-08-28T04:36:20.950

You could use this code. I tested a code like this for Buttons and WinForm. I hope the code helps you, in your case.

resourceList.Where(resourceOne =>
        {
            string s = (string)resourceOne;
            gridBtn.Children.OfType<ToggleButton>().Where(c =>
            {
                var TagPlusOne = Convert.ToInt32(c.Tag) + 1;
                var PaddedResult = TagPlusOne.ToString().PadLeft(3, '0');
                return PaddedResult == s;
            }).ToList().ForEach(c =>
            {
                c.BorderBrush = Brushes.Red;
                c.BorderThickness = new Thickness(3, 3, 3, 3);
            });
            return true;
        });

I think you could use Select instead of Foreach aswell.

esourceList.Where(resourceOne =>
        {
            string s = (string)resourceOne;
            var enumerable = ActiveForm.Controls.OfType<Button>().Where(control =>
            {
                var TagPlusOne = Convert.ToInt32(control.Tag) + 1;
                var PaddedResult = TagPlusOne.ToString().PadLeft(3, '0');
                return PaddedResult == s;
            }).Select(control =>
            {
                control.BackColor = Color.Aqua;
                control.Cursor = Cursors.WaitCursor;
                return control;
            });
            return true;
        });

thanks i already found the workable answer above with simplified code . thanks again — Loh ZhiCheng, Aug 28 '18 at 04:53

Linq from multiple Foreach

5 Answers5