原文出处: http://m.blog.csdn.net/blog/yeqi3000/8920834
/// <summary>
/// 数字输入文本框
/// 创建者:Maximus
/// 创建时间:2013-5-13
/// 版本:0.2
/// 可输入:数字0-9,小数点,减号
/// 可设置小数位数
/// 可设置数值上下限,若上下限均设置为0,则上下限值无效
/// </summary>
public class NumericBox : TextBox
{
public NumericBox()
{
this.LostFocus+=new RoutedEventHandler(NumericBox_LostFocus);
this.Text = "0";
}
#region 属性
/// <summary>
/// 在属性设计器中隐藏文本属性
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never), Browsable(false)]
public new string Text
{
get
{
return base.Text;
}
set
{
base.Text = value;
}
}
public static readonly DependencyProperty DecimalProperty = DependencyProperty.Register("DecimalPlaces", typeof(ushort), typeof(NumericBox));
/// <summary>
/// 允许输入的小数点个数
/// </summary>
[Description("小数位数,0表示不能输入小数"),Category("输入设置")]
public ushort DecimalPlaces
{
get {
return (ushort)GetValue(DecimalProperty);
}
set {
SetValue(DecimalProperty, value);
}
}
public static readonly DependencyProperty MaximumProperty =
DependencyProperty.Register("Maximum", typeof(decimal), typeof(NumericBox));
/// <summary>
/// 可输入的最大值
/// </summary>
[Description("可输入的最大值"), Category("输入设置"),DefaultValue(0)]
public decimal Maximum
{
get
{
return (decimal)GetValue(MaximumProperty);
}
set
{
SetValue(MaximumProperty, value);
}
}
public static readonly DependencyProperty MinimumProperty =
DependencyProperty.Register("Minimum", typeof(decimal), typeof(NumericBox));
/// <summary>
/// 可输入的最小值
/// </summary>
[Description("可输入的最小值"), Category("输入设置"), DefaultValue(0)]
public decimal Minimum
{
get
{
return (decimal)GetValue(MinimumProperty);
}
set
{
SetValue(MinimumProperty, value);
}
}
public static readonly DependencyProperty ValueProperty =
DependencyProperty.Register("Value", typeof(decimal), typeof(NumericBox),
new PropertyMetadata(new decimal(0), null, OnValueChanged));
/// <summary>
/// 数值
/// </summary>
[Description("数值"), Category("输入设置"),DefaultValue(0)]
public decimal Value
{
get
{
return (decimal)GetValue(ValueProperty);
}
set
{
SetValue(ValueProperty, value);
}
}
private static Object OnValueChanged(DependencyObject d, object baseValue)
{
decimal value = (decimal)baseValue;
NumericBox Nmbox = d as NumericBox;
Nmbox.Text = value.ToString();
return value;
}
#endregion
#region 内部事件
/// <summary>
/// 丢失焦点
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void NumericBox_LostFocus(object sender, RoutedEventArgs e)
{
if (TextCheck())
{
this.Value = Convert.ToDecimal(this.Text);
}
}
#endregion
#region 输入限制
/// <summary>
/// 文本内容变更检查
/// </summary>
/// <param name="e"></param>
protected override void OnTextChanged(TextChangedEventArgs e)
{
if (this.Text.IndexOf('.') == 0
|| ((this.Text.Length > 1 && this.Text.Substring(0, 1) == "0" && this.Text.Substring(1, 1) != ".")))
{
this.Text = this.Text.Remove(0, 1);
this.SelectionStart = this.Text.Length;
}
}
/// <summary>
/// 输入限制
/// </summary>
/// <param name="e"></param>
protected override void OnKeyDown(KeyEventArgs e)
{//可输入:数字0-9,小数点,减号
int PPos = this.Text.IndexOf('.');//获取当前小数点位置
if ((e.Key >= Key.D1 && e.Key <= Key.D9)//数字0-9键
|| (e.Key >= Key.NumPad1 && e.Key <= Key.NumPad9))//小键盘数字0-9
{
if (PPos != -1 && this.SelectionStart > PPos)//可输入小数,且输入点在小数点后
{
if (this.Text.Length - PPos - 1 < DecimalPlaces)//小数位数是否已满
{
e.Handled = false;
return;
}
}
else
{
e.Handled = false;
return;
}
}
else if (e.Key == Key.D0 || e.Key == Key.NumPad0)//输入的是0
{
if (this.SelectionStart > 0)
{//非首位输入
if (this.Text.Substring(0, 1) != "0")
{//首位数字不为0
e.Handled = false;
return;
}
else
{//首位数字为0,
if (PPos == 1 && this.Text.Length - PPos - 1 < DecimalPlaces)
{ //0后面是小数点,小数位数未满
e.Handled = false;
return;
}
}
}
else
{
e.Handled = false;
return;
}
}
else if (e.Key == Key.Decimal || e.Key == Key.OemPeriod)//小数点
{
if (PPos == -1 && this.DecimalPlaces > 0)//未输入过小数点,且允许输入小数
{
if (this.SelectionStart == 0)
{
this.Text = "0.";
}
e.Handled = false;
return;
}
}
else if (e.Key == Key.Subtract || e.Key == Key.OemMinus)//减号
{
if (this.Minimum < 0)//允许输入的最小值小于0
{
if (this.Text.IndexOf('-') == -1 && this.SelectionStart == 0)
{
e.Handled = false;
return;
}
}
}
e.Handled = true;
}
/// <summary>
/// 输入合法性检查
/// </summary>
private bool TextCheck()
{
try
{
decimal d = Convert.ToDecimal(this.Text.Trim());//转换为数字
if (this.DecimalPlaces > 0)
{
d = Math.Round(d, this.DecimalPlaces);//舍入小数位数
}
if (!(this.Minimum == 0 && this.Maximum == 0))
{
if (d < this.Minimum)//输入的值小于最小值
{
d = this.Minimum;
}
else if (d > this.Maximum)//输入的值大于最大值
{
d = this.Maximum;
}
}
this.Value = d;
}
catch {
this.Value = this.Minimum;
return false;
}
return true;
}
#endregion
}