WPF自定义实现IP地址输入控件

public class IPRangeValidationRule : ValidationRule
{
 private int _min;
 private int _max;

 public int Min
 {
  get { return _min; }
  set { _min = value; }
 }

 public int Max
 {
  get { return _max; }
  set { _max = value; }
 }

 public override ValidationResult Validate(object value, CultureInfo cultureInfo)
 {
  int val = 0;
  var strVal = (string)value;
  try
  {
   if (strVal.Length > 0)
   {
    if (strVal.EndsWith("."))
    {
     return CheckRanges(strVal.Replace(".", ""));
    }

    // Allow dot character to move to next box
    return CheckRanges(strVal);
   }
  }
  catch (Exception e)
  {
   return new ValidationResult(false, "Illegal characters or " + e.Message);
  }

  if ((val  Max))
  {
   return new ValidationResult(false,
    "Please enter the value in the range: " + Min + " - " + Max + ".");
  }
  else
  {
   return ValidationResult.ValidResult;
  }
 }

 private ValidationResult CheckRanges(string strVal)
 {
  if (int.TryParse(strVal, out var res))
  {
   if ((res  Max))
   {
    return new ValidationResult(false,
     "Please enter the value in the range: " + Min + " - " + Max + ".");
   }
   else
   {
    return ValidationResult.ValidResult;
   }
  }
  else
  {
   return new ValidationResult(false, "Illegal characters entered");
  }
 }
}

public static class FocusChangeExtension
{
 public static bool GetIsFocused(DependencyObject obj)
 {
  return (bool)obj.GetValue(IsFocusedProperty);
 }

 public static void SetIsFocused(DependencyObject obj, bool value)
 {
  obj.SetValue(IsFocusedProperty, value);
 }

 public static readonly DependencyProperty IsFocusedProperty =
  DependencyProperty.RegisterAttached(
   "IsFocused", typeof(bool), typeof(FocusChangeExtension),
   new UIPropertyMetadata(false, OnIsFocusedPropertyChanged));

 private static void OnIsFocusedPropertyChanged(
  DependencyObject d,
  DependencyPropertyChangedEventArgs e)
 {
  var cOntrol= (UIElement)d;
  if ((bool)e.NewValue)
  {
   control.Focus();
  }
 }
}

private void Part2_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
 if (e.Key == Key.Back && part2.Text == "")
 {
  part1.Focus();
 }
 if (e.Key == Key.Right && part2.CaretIndex == part2.Text.Length)
 {
  part3.Focus();
  e.Handled = true;
 }
 if (e.Key == Key.Left && part2.CaretIndex == 0)
 {
  part1.Focus();
  e.Handled = true;
 }

 if (e.KeyboardDevice.Modifiers.HasFlag(ModifierKeys.Control) && e.Key == Key.C)
 {
  if (part2.SelectiOnLength== 0)
  {
   var vm = this.DataContext as IpAddressViewModel;
   Clipboard.SetText(vm.AddressText);
  }
 }
}

public class IpAddressViewModel : INotifyPropertyChanged
{
 public event EventHandler AddressChanged;

 public string AddressText
 {
  get { return $"{Part1&＃63;&＃63;"0"}.{Part2&＃63;&＃63;"0"}.{Part3&＃63;&＃63;"0"}.{Part4&＃63;&＃63;"0"}"; }
 }

 private bool isPart1Focused;

 public bool IsPart1Focused
 {
  get { return isPart1Focused; }
  set { isPart1Focused = value; OnPropertyChanged(); }
 }

 private string part1;

 public string Part1
 {
  get { return part1; }
  set
  {
   part1 = value;
   SetFocus(true, false, false, false);

   var moveNext = CanMoveNext(ref part1);

   OnPropertyChanged();
   OnPropertyChanged(nameof(AddressText));
   AddressChanged&＃63;.Invoke(this, EventArgs.Empty);

   if (moveNext)
   {
    SetFocus(false, true, false, false);
   }
  }
 }
 
 private bool isPart2Focused;

 public bool IsPart2Focused
 {
  get { return isPart2Focused; }
  set { isPart2Focused = value; OnPropertyChanged(); }
 }


 private string part2;

 public string Part2
 {
  get { return part2; }
  set
  {
   part2 = value;
   SetFocus(false, true, false, false);

   var moveNext = CanMoveNext(ref part2);

   OnPropertyChanged();
   OnPropertyChanged(nameof(AddressText));
   AddressChanged&＃63;.Invoke(this, EventArgs.Empty);

   if (moveNext)
   {
    SetFocus(false, false, true, false);
   }
  }
 }

 private bool isPart3Focused;

 public bool IsPart3Focused
 {
  get { return isPart3Focused; }
  set { isPart3Focused = value; OnPropertyChanged(); }
 }

 private string part3;

 public string Part3
 {
  get { return part3; }
  set
  {
   part3 = value;
   SetFocus(false, false, true, false);
   var moveNext = CanMoveNext(ref part3);

   OnPropertyChanged();
   OnPropertyChanged(nameof(AddressText));
   AddressChanged&＃63;.Invoke(this, EventArgs.Empty);

   if (moveNext)
   {
    SetFocus(false, false, false, true);
   }
  }
 }

 private bool isPart4Focused;

 public bool IsPart4Focused
 {
  get { return isPart4Focused; }
  set { isPart4Focused = value; OnPropertyChanged(); }
 }

 private string part4;

 public string Part4
 {
  get { return part4; }
  set
  {
   part4 = value;
   SetFocus(false, false, false, true);
   var moveNext = CanMoveNext(ref part4);

   OnPropertyChanged();
   OnPropertyChanged(nameof(AddressText));
   AddressChanged&＃63;.Invoke(this, EventArgs.Empty);

  }
 }
 
 public void SetAddress(string address)
 {
  if (string.IsNullOrWhiteSpace(address))
   return;

  var parts = address.Split('.');   

  if (int.TryParse(parts[0], out var num0))
  {
   Part1 = num0.ToString();
  }

  if (int.TryParse(parts[1], out var num1))
  {
   Part2 = parts[1];
  }

  if (int.TryParse(parts[2], out var num2))
  {
   Part3 = parts[2];
  }

  if (int.TryParse(parts[3], out var num3))
  {
   Part4 = parts[3];
  }

 }

 private bool CanMoveNext(ref string part)
 {
  bool moveNext = false;

  if (!string.IsNullOrWhiteSpace(part))
  {
   if (part.Length >= 3)
   {
    moveNext = true;
   }

   if (part.EndsWith("."))
   {
    moveNext = true;
    part = part.Replace(".", "");
   }
  }

  return moveNext;
 }

 private void SetFocus(bool part1, bool part2, bool part3, bool part4)
 {
  IsPart1Focused = part1;
  IsPart2Focused = part2;
  IsPart3Focused = part3;
  IsPart4Focused = part4;
 }

 public event PropertyChangedEventHandler PropertyChanged;


 protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
 {
  PropertyChanged&＃63;.Invoke(this, new PropertyChangedEventArgs(propertyName));
 }
}