Question

如何将以下多个foreach转换为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);
                }
            }
        }
    }

Answer 1

您确实不能，但是可以使用Where和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);
    }
}

免责声明：完全未经测试（再次）

Answer 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);
}

Answer 3

您可以执行以下操作（由于没有您的环境，我无法测试）：

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);
    });

Answer 4

最后，您需要使用foreach或类似名称来设置按钮上的属性，因为LINQ是用于查询数据（通常无副作用），而不是变异他们。但是，您可以使用LINQ来简化查找您要编辑的按钮。例如您的代码可以归结为：

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);
}

可以进一步进行调整/优化/重构。请注意，我已将PadLeft(3, '0')替换为具有相同功能的D3标准数字格式字符串。

Answer 5

您可以使用此代码。我为Buttons和WinForm测试了这样的代码。希望代码对您有帮助。

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;
        });

我认为您也可以使用Select代替Foreach。

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;
        });

来自多个Foreach的Linq

5 个答案: