由于项目需要，最近写了一个数字输入文本框，在此作个备忘。
1.代码调用
<controls:NumericBox Height="32" Width="80"
MinValue ="0"
MaxValue="100"
Digits ="0"
CurValue="{Binding LabelSize, Mode=TwoWay}" >
</controls:NumericBox>
2.样式（InputMethod.IsInputMethodEnabled项设置为false后可以屏蔽输入法）
<Style TargetType="{x:Type local:NumericBox}" BasedOn="{StaticResource MetroTextBox}">
<Setter Property="InputMethod.IsInputMethodEnabled" Value="False" />
</Style>
3.后台逻辑
public class NumericBox : TextBox
{
#region DependencyProperty
private const double CURVALUE = 0; //当前值
private const double MINVALUE = double.MinValue; //最小值
private const double MAXVALUE = double.MaxValue; //最大值
private const int DIGITS = 15; //小数点精度
public static readonly DependencyProperty CurValueProperty;
public static readonly DependencyProperty MinValueProperty;
public static readonly DependencyProperty MaxValueProperty;
public static readonly DependencyProperty DigitsProperty;
public double CurValue
{
get
{
return (double)GetValue(CurValueProperty);
}
set
{
double v = value;
if (value < MinValue)
{
v = MinValue;
}
else if (value > MaxValue)
{
v = MaxValue;
}
v = Math.Round(v, Digits);
SetValue(CurValueProperty, v);
// if do not go into OnCurValueChanged then force update ui
if (v != value)
{
this.Text = v.ToString();
}
}
}
public double MinValue
{
get
{
return (double)GetValue(MinValueProperty);
}
set
{
SetValue(MinValueProperty, value);
}
}
public double MaxValue
{
get
{
return (double)GetValue(MaxValueProperty);
}
set
{
SetValue(MaxValueProperty, value);
}
}
public int Digits
{
get
{
return (int)GetValue(DigitsProperty);
}
set
{
int digits = value;
if (digits <= 0)
{
digits = 0;
}
if (digits > 15)
{
digits = 15;
}
SetValue(DigitsProperty, value);
}
}
static NumericBox()
{
FrameworkPropertyMetadata metadata = new FrameworkPropertyMetadata(CURVALUE, new PropertyChangedCallback(OnCurValueChanged));
CurValueProperty = DependencyProperty.Register("CurValue", typeof(double), typeof(NumericBox), metadata);
metadata = new FrameworkPropertyMetadata(MINVALUE, new PropertyChangedCallback(OnMinValueChanged));
MinValueProperty = DependencyProperty.Register("MinValue", typeof(double), typeof(NumericBox), metadata);
metadata = new FrameworkPropertyMetadata(MAXVALUE, new PropertyChangedCallback(OnMaxValueChanged));
MaxValueProperty = DependencyProperty.Register("MaxValue", typeof(double), typeof(NumericBox), metadata);
metadata = new FrameworkPropertyMetadata(DIGITS, new PropertyChangedCallback(OnDigitsChanged));
DigitsProperty = DependencyProperty.Register("Digits", typeof(int), typeof(NumericBox), metadata);
}
private static void OnCurValueChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
double value = (double)e.NewValue;
NumericBox numericBox = (NumericBox)sender;
numericBox.Text = value.ToString();
}
private static void OnMinValueChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
double minValue = (double)e.NewValue;
NumericBox numericBox = (NumericBox)sender;
numericBox.MinValue = minValue;
}
private static void OnMaxValueChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
double maxValue = (double)e.NewValue;
NumericBox numericBox = (NumericBox)sender;
numericBox.MaxValue = maxValue;
}
private static void OnDigitsChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
int digits = (int)e.NewValue;
NumericBox numericBox = (NumericBox)sender;
numericBox.CurValue = Math.Round(numericBox.CurValue, digits);
numericBox.MinValue = Math.Round(numericBox.MinValue, digits);
numericBox.MaxValue = Math.Round(numericBox.MaxValue, digits);
}
#endregion
public NumericBox()
{
this.TextChanged += NumericBox_TextChanged;
this.PreviewKeyDown += NumericBox_KeyDown;
this.LostFocus += NumericBox_LostFocus;
DataObject.AddPastingHandler(this, NumericBox_Pasting);
}
void NumericBox_TextChanged(object sender, TextChangedEventArgs e)
{
NumericBox numericBox = sender as NumericBox;
if (string.IsNullOrEmpty(numericBox.Text))
{
return;
}
TrimZeroStart();
double value = MinValue;
if (!Double.TryParse(numericBox.Text, out value))
{
return;
}
if (value != this.CurValue)
{
this.CurValue = value;
}
}
void NumericBox_KeyDown(object sender, KeyEventArgs e)
{
Key key = e.Key;
if(IsControlKeys(key))
{
return;
}
else if (IsDigit(key))
{
return;
}
else if (IsSubtract(key)) //-
{
TextBox textBox = sender as TextBox;
string str = textBox.Text;
if (str.Length > 0 && textBox.SelectionStart != 0)
{
e.Handled = true;
}
}
else if (IsDot(key)) //point
{
if (this.Digits > 0)
{
TextBox textBox = sender as TextBox;
string str = textBox.Text;
if (str.Contains('.') || str == "-")
{
e.Handled = true;
}
}
else
{
e.Handled = true;
}
}
else
{
e.Handled = true;
}
}
void NumericBox_LostFocus(object sender, RoutedEventArgs e)
{
NumericBox numericBox = sender as NumericBox;
if (string.IsNullOrEmpty(numericBox.Text))
{
numericBox.Text = this.CurValue.ToString();
}
}
private void NumericBox_Pasting(object sender, DataObjectPastingEventArgs e)
{
e.CancelCommand();
}
private static readonly List<Key> _controlKeys = new List<Key>
{
Key.Back,
Key.CapsLock,
Key.Down,
Key.End,
Key.Enter,
Key.Escape,
Key.Home,
Key.Insert,
Key.Left,
Key.PageDown,
Key.PageUp,
Key.Right,
Key.Tab,
Key.Up
};
public static bool IsControlKeys(Key key)
{
return _controlKeys.Contains(key);
}
public static bool IsDigit(Key key)
{
bool shiftKey = (Keyboard.Modifiers & ModifierKeys.Shift) != 0;
bool retVal;
if (key >= Key.D0 && key <= Key.D9 && !shiftKey)
{
retVal = true;
}
else
{
retVal = key >= Key.NumPad0 && key <= Key.NumPad9;
}
return retVal;
}
public static bool IsDot(Key key)
{
bool shiftKey = (Keyboard.Modifiers & ModifierKeys.Shift) != 0;
bool flag = false;
if (key == Key.Decimal)
{
flag = true;
}
if (key == Key.OemPeriod && !shiftKey)
{
flag = true;
}
return flag;
}
public static bool IsSubtract(Key key)
{
bool shiftKey = (Keyboard.Modifiers & ModifierKeys.Shift) != 0;
bool flag = false;
if (key == Key.Subtract)
{
flag = true;
}
if (key == Key.OemMinus && !shiftKey)
{
flag = true;
}
return flag;
}
private void TrimZeroStart()
{
if(this.Text.Length == 1)
{
return;
}
string resultText = this.Text;
int zeroCount = 0;
foreach (char c in this.Text)
{
if (c == '0') { zeroCount++; }
else { break; }
}
if (zeroCount == 0)
{
return;
}
if (this.Text.Contains('.'))
{
if (this.Text[zeroCount] != '.')
{
resultText = this.Text.TrimStart('0');
}
else if (zeroCount > 1)
{
resultText = this.Text.Substring(zeroCount - 1);
}
}
else if (zeroCount > 0)
{
resultText = this.Text.TrimStart('0');
}
}
}