Question

问题我有一个我想使用的自定义划分和征服数组排序器。这一切都运行良好，直到我尝试在我的控制器中的数组上使用它我收到此消息.. NoMethodError (undefined method '<=' for #<Entry:0x0000000ac7d850>)：任何帮助将不胜感激，谢谢！

这是我的条目模型，我在控制器中调用mergesort方法。

def self.mergesort(container)
  return container if (container.size <= 1)
  mid   = container.size / 2
  left  = container[0...mid]
  right = container[mid...container.size]
  merge(mergesort(left), mergesort(right))
end

def self.merge(left, right)
  sorted = []
  until left.empty? or right.empty?
    (left.first <= right.first) ? sorted << left.shift : sorted << right.shift
  end
  sorted + left + right
end

这是我的Entry控制器，我试图调用它。

  def pending_sort 
    @ent_sort = Entry.where("section = ? and approve_disapprove = ?", @mgr_section, '3')


    @ent = Entry.mergesort(@ent_sort)

  end

Answer 1

left或right的第一个元素可能有irb(main):001:0> left = [] => [] irb(main):002:0> right = [1] => [1] irb(main):003:0> left.first => nil irb(main):004:0> left.first <= right.first NoMethodError: undefined method `<=' for nil:NilClass from (irb):4 from /usr/bin/irb:11:in `<main>'。

nil

您可以通过将(left.first <= right.first) ? sorted << left.shift : sorted << right.shift转换为其他值来修复错误。例如，如果您要比较的值始终为整数，则可以更改以下行：

(left.first.to_i <= right.first.to_i) ? sorted << left.shift : sorted << right.shift

到此：

this.IpOctetFirst.KeyDown += delegate(object sender, KeyEventArgs e)
            {
                if (e.Key == Key.Tab ||
                    e.Key == Key.Home ||
                    e.Key == Key.End ||
                    e.Key == Key.Left ||
                    e.Key == Key.Right ||
                    e.Key == Key.Back ||
                    e.Key == Key.Delete ||
                    e.Key == Key.Decimal ||
                    (e.Key >= Key.D0 && e.Key <= Key.D9) ||
                    (e.Key >= Key.NumPad0 && e.Key <= Key.NumPad9) ||

/////////////////////////////////example: having error in this line:
                    (e.Key == Key.Unknown && e.PlatformKeyCode == 190))
                {
                    if (this.IpOctetFirst.Text.Length == 3 &&
                        this.IpOctetFirst.SelectedText.Length == 0 &&
                        e.Key != Key.Tab &&
                        e.Key != Key.Left &&
                        e.Key != Key.Right &&
                        e.Key != Key.Decimal && 
                        (e.Key != Key.Unknown || e.PlatformKeyCode != 190))
                    {
                        e.Handled = true;
                        return;
                    }
                    switch (e.Key)
                    {
                        case Key.Right:
                            if (this.IpOctetFirst.SelectionStart == this.IpOctetFirst.Text.Length)
                            {
                                this.IpOctetSecond.Focus();
                                this.IpOctetSecond.SelectionStart = 0;
                            }
                            break;
                        case Key.Decimal:
                        case Key.Unknown:
                            if (this.IpOctetFirst.SelectionStart == 0)
                                e.Handled = true;
                            break;
                    }
                }
                else
                {
                    e.Handled = true;
                }
            };

但想想它会如何影响你的功能......如果它不是你真正想做的事情，它可能会破坏它。

为什么我在我的ROR应用

1 个答案: