WPF实现的数字输入框和IP地址输入框
数字输入框
简介
在业务中，我们经常需要限制用户的输入，比如限制输入长度，限制只能输入数字等等。限制输入长度WPF内置的TextBox已经帮我们解决了，但是限制输入数字却并未在WPF中内置解决方案。使用第三方的控件又要多增加一个引用，于是决定自己写一个。
在写的过程中发现需要考虑的问题比较多，比如限制输入法、部分限制输入小数点和负号、限制输入字母和其它符号、粘贴时做特殊处理等等。值得一提的是，将文本绑定到Double型且将UpdateSourceTrigger设为PropertyChanged时，出现了界面上包含小数点，但是通过Text获取的文本却并不包含小数点的情况，猜测原因是因为绑定更新和自动类型转换出现的问题。
代码
namespace YiYan127.WPF.Controls
{
using System;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
/// <summary>
/// 输入数值的文本框
/// </summary>
public class NumbericTextBox : TextBox
{
#region Fields
#region DependencyProperty
/// <summary>
/// 最大值的依赖属性
/// </summary>
public static readonly DependencyProperty MaxValueProperty = DependencyProperty.Register(
"MaxValue",
typeof(double),
typeof(NumbericTextBox),
new PropertyMetadata(double.MaxValue));
/// <summary>
/// 最小值的依赖属性
/// </summary>
public static readonly DependencyProperty MinValueProperty = DependencyProperty.Register(
"MinValue",
typeof(double),
typeof(NumbericTextBox),
new PropertyMetadata(double.MinValue));
/// <summary>
/// 精度的依赖属性
/// </summary>
public static readonly DependencyProperty PrecisionProperty = DependencyProperty.Register(
"Precision",
typeof(ushort),
typeof(NumbericTextBox),
new PropertyMetadata((ushort)2));
#endregion DependencyProperty
/// <summary>
/// 先前合法的文本
/// </summary>
private string lastLegalText;
/// <summary>
/// 是否为粘贴
/// </summary>
private bool isPaste;
public event EventHandler<TextChangedEventArgs> PreviewTextChanged;
#endregion Fields
#region Constructor
/// <summary>
/// 构造函数
/// </summary>
public NumbericTextBox()
{
this.PreviewTextInput += this.NumbericTextBoxPreviewTextInput;
this.TextChanged += this.NumbericTextBoxTextChanged;
this.PreviewKeyDown += this.NumbericTextBox_PreviewKeyDown;
this.LostFocus += this.NumbericTextBoxLostFocus;
InputMethod.SetIsInputMethodEnabled(this, false);
this.Loaded += this.NumbericTextBoxLoaded;
}
#endregion Constructor
#region Properties
/// <summary>
/// 最大值,可取
/// </summary>
public double MaxValue
{
get { return (double)this.GetValue(MaxValueProperty); }
set { this.SetValue(MaxValueProperty, value); }
}
/// <summary>
/// 最小值,可取
/// </summary>
public double MinValue
{
get { return (double)this.GetValue(MinValueProperty); }
set { this.SetValue(MinValueProperty, value); }
}
/// <summary>
/// 精度,即精确到小数点后的位数
/// </summary>
public ushort Precision
{
get { return (ushort)this.GetValue(PrecisionProperty); }
set { this.SetValue(PrecisionProperty, value); }
}
#endregion Properties
protected virtual void OnPreviewTextChanged(TextChangedEventArgs e)
{
if (this.PreviewTextChanged != null)
{
this.PreviewTextChanged(this, e);
}
}
#region Private Methods
/// <summary>
/// 处理粘贴的情况
/// </summary>
protected virtual void HandlePaste()
{
this.isPaste = false;
// 处理符号的标志
bool handledSybmol = false;
// 处理小数点的标志
bool handledDot = false;
// 当前位对应的基数
double baseNumber = 1;
// 转换后的数字
double number = 0;
// 上一次合法的数字
double lastNumber = 0;
// 小数点后的位数
double precision = 0;
foreach (var c in this.Text)
{
if (!handledSybmol && (c == '-'))
{
baseNumber = -1;
handledSybmol = true;
}
if ((c >= '0') && (c <= '9'))
{
int digit = c - '0';
if (!handledDot)
{
number = (number * baseNumber) + digit;
baseNumber = 10;
}
else
{
baseNumber = baseNumber / 10;
number += digit * baseNumber;
}
// 正负号必须位于最前面
handledSybmol = true;
}
if (c == '.')
{
// 精度已经够了
if (precision + 1 > this.Precision)
{
break;
}
handledDot = true;
// 此时正负号不能起作用
handledSybmol = true;
baseNumber = 0.1;
precision++;
}
if ((number < this.MinValue) || (number > this.MaxValue))
{
this.Text = lastNumber.ToString(CultureInfo.InvariantCulture);
this.SelectionStart = this.Text.Length;
return;
}
lastNumber = number;
}
this.Text = number.ToString(CultureInfo.InvariantCulture);
this.SelectionStart = this.Text.Length;
}
#endregion Private Methods
#region Overrides of TextBoxBase
#endregion
#region Events Handling
private void NumbericTextBoxLoaded(object sender, RoutedEventArgs e)
{
if (this.MinValue > this.MaxValue)
{
this.MinValue = this.MaxValue;
}
if (string.IsNullOrEmpty(this.Text))
{
double val = (this.MaxValue + this.MinValue) / 2;
val = Math.Round(val, this.Precision);
this.Text = val.ToString(CultureInfo.InvariantCulture);
}
this.isPaste = true;
}
/// <summary>
/// The numberic text box preview text input.
/// </summary>
/// <param name="sender"> The sender.</param>
/// <param name="e"> The e.</param>
private void NumbericTextBoxPreviewTextInput(object sender, TextCompositionEventArgs e)
{
// 如果是粘贴不会引发该事件
this.isPaste = false;
short val;
// 输入非数字
if (!short.TryParse(e.Text, out val))
{
// 小于0时,可输入负号
if ((this.MinValue < 0) && (e.Text == "-"))
{
int minusPos = this.Text.IndexOf('-');
// 未输入负号且负号在第一位
if ((minusPos == -1) && (0 == this.SelectionStart))
{
return;
}
}
// 精度大于0时,可输入小数点
if ((this.Precision > 0) && (e.Text == "."))
{
// 解决UpdateSourceTrigger为PropertyChanged时输入小数点文本与界面不一致的问题
if (this.SelectionStart > this.Text.Length)
{
e.Handled = true;
return;
}
// 小数点位置
int dotPos = this.Text.IndexOf('.');
// 未存在小数点可输入
if (dotPos == -1)
{
return;
}
// 已存在小数点但处于选中状态,也可输入小数点
if ((this.SelectionStart >= dotPos) && (this.SelectionLength > 0))
{
return;
}
}
e.Handled = true;
}
else
{
int dotPos = this.Text.IndexOf('.');
int cursorIndex = this.SelectionStart;
// 已经存在小数点,且小数点在光标后
if ((dotPos != -1) && (dotPos < cursorIndex))
{
// 不允许输入超过精度的数
if (((this.Text.Length - dotPos) > this.Precision) && (this.SelectionLength == 0))
{
e.Handled = true;
}
}
}
}
/// <summary>
/// The numberic text box text changed.
/// </summary>
/// <param name="sender"> The sender.</param>
/// <param name="e"> The e.</param>
private void NumbericTextBoxTextChanged(object sender, TextChangedEventArgs e)
{
if (this.lastLegalText == this.Text)
{
return;
}
this.OnPreviewTextChanged(e);
// 允许为空
if (string.IsNullOrEmpty(this.Text))
{
return;
}
// 粘贴而来的文本
if (this.isPaste)
{
this.HandlePaste();
this.lastLegalText = this.Text;
return;
}
double val;
if (double.TryParse(this.Text, out val))
{
// 保存光标位置
int selectIndex = this.SelectionStart;
if ((val > this.MaxValue) || (val < this.MinValue))
{
this.Text = this.lastLegalText;
this.SelectionStart = selectIndex;
return;
}
this.lastLegalText = this.Text;
}
this.isPaste = true;
}
/// <summary>
/// The numberic text box_ preview key down.
/// </summary>
/// <param name="sender"> The sender.</param>
/// <param name="e"> The e.</param>
private void NumbericTextBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
// 过滤空格
if (e.Key == Key.Space)
{
e.Handled = true;
}
}
/// <summary>
/// The numberic text box_ lost focus.
/// </summary>
/// <param name="sender"> The sender.</param>
/// <param name="e"> The e.</param>
private void NumbericTextBoxLostFocus(object sender, RoutedEventArgs e)
{
if (string.IsNullOrEmpty(this.Text))
{
this.Text = this.lastLegalText;
}
}
#endregion Events Handling
}
}
IP地址输入框
XAML
<UserControl x:Class="YiYan127.WPF.Controls.IpAddressControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="clr-namespace:YiYan127.WPF.Controls">
<UniformGrid Columns="4" TextBoxBase.GotFocus="TextBox_OnGotFocus">
<DockPanel Margin="5,2">
<TextBlock VerticalAlignment="Center" DockPanel.Dock="Right" Text="." />
<controls:NumbericTextBox x:Name="IPPart1" MaxValue="255" MinValue="0"
Precision="0" />
</DockPanel>
<DockPanel Margin="0,2,5,2">
<TextBlock VerticalAlignment="Center" DockPanel.Dock="Right" Text="." />
<controls:NumbericTextBox x:Name="IPPart2" MaxValue="255" MinValue="0"
Precision="0" />
</DockPanel>
<DockPanel Margin="0,2,5,2">
<TextBlock VerticalAlignment="Center" DockPanel.Dock="Right" Text="." />
<controls:NumbericTextBox x:Name="IPPart3" MaxValue="255" MinValue="0"
Precision="0" />
</DockPanel>
<controls:NumbericTextBox x:Name="IPPart4" Margin="0,2,5,2" MaxValue="255"
MinValue="0" Precision="0" />
</UniformGrid>
</UserControl>
后台代码
namespace YiYan127.WPF.Controls
{
using System;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Text.RegularExpressions;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
/// <summary>
/// IP地址输入框
/// </summary>
public partial class IpAddressControl
{
#region Fields
/// <summary>
/// IP地址的依赖属性
/// </summary>
public static readonly DependencyProperty IPProperty = DependencyProperty.Register(
"IP",
typeof(string),
typeof(IpAddressControl),
new FrameworkPropertyMetadata(DefaultIP, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, IPChangedCallback));
/// <summary>
/// IP地址的正则表达式
/// </summary>
public static readonly Regex IpRegex = new
Regex(@"^((2[0-4]\d|25[0-5]|(1\d{2})|([1-9]?[0-9]))\.){3}(2[0-4]\d|25[0-4]|(1\d{2})|([1-9][0-9])|([1-9]))$");
/// <summary>
/// 默认IP地址
/// </summary>
private const string DefaultIP = "127.0.0.1";
private static readonly Regex PartIprRegex = new Regex(@"^(\.?(2[0-4]\d|25[0-5]|(1\d{2})|([1-9]?[0-9]))\.?)+$");
/// <summary>
/// 输入框的集合
/// </summary>
private readonly List<NumbericTextBox> numbericTextBoxs = new List<NumbericTextBox>();
/// <summary>
/// 当前活动的输入框
/// </summary>
private NumbericTextBox currentNumbericTextBox;
#endregion Fields
#region Constructors
public IpAddressControl()
{
InitializeComponent();
this.numbericTextBoxs.Add(this.IPPart1);
this.numbericTextBoxs.Add(this.IPPart2);
this.numbericTextBoxs.Add(this.IPPart3);
this.numbericTextBoxs.Add(this.IPPart4);
this.KeyUp += this.IpAddressControlKeyUp;
this.UpdateParts(this);
foreach (var numbericTextBox in this.numbericTextBoxs)
{
numbericTextBox.PreviewTextChanged += this.NumbericTextBox_OnPreviewTextChanged;
}
foreach (var numbericTextBox in this.numbericTextBoxs)
{
numbericTextBox.TextChanged += this.TextBoxBase_OnTextChanged;
}
}
#endregion Constructors
#region Properties
public string IP
{
get
{
return (string)GetValue(IPProperty);
}
set
{
SetValue(IPProperty, value);
}
}
#endregion Properties
#region Private Methods
/// <summary>
/// IP值改变的响应
/// </summary>
/// <param name="dependencyObject"></param>
/// <param name="dependencyPropertyChangedEventArgs"></param>
private static void IPChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
{
if (dependencyPropertyChangedEventArgs.NewValue == null)
{
throw new Exception("IP can not be null");
}
var control = dependencyObject as IpAddressControl;
if (control != null)
{
control.UpdateParts(control);
}
}
private void UpdateParts(IpAddressControl control)
{
string[] parts = control.IP.Split(new[] { '.' });
control.IPPart1.Text = parts[0];
control.IPPart2.Text = parts[1];
control.IPPart3.Text = parts[2];
control.IPPart4.Text = parts[3];
}
#endregion Private Methods
#region Event Handling
/// <summary>
/// 按键松开的响应
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void IpAddressControlKeyUp(object sender, KeyEventArgs e)
{
if (e.Key == Key.OemPeriod || e.Key == Key.Decimal)
{
if (this.currentNumbericTextBox != null)
{
int index = this.numbericTextBoxs.IndexOf(this.currentNumbericTextBox);
int next = (index + 1) % this.numbericTextBoxs.Count;
this.numbericTextBoxs[next].Focus();
this.numbericTextBoxs[next].SelectionStart = this.numbericTextBoxs[next].Text.Length;
}
}
}
/// <summary>
/// 获得焦点的响应
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void TextBox_OnGotFocus(object sender, RoutedEventArgs e)
{
this.currentNumbericTextBox = e.OriginalSource as NumbericTextBox;
}
private void NumbericTextBox_OnPreviewTextChanged(object sender, TextChangedEventArgs e)
{
var numbericTextBox = sender as NumbericTextBox;
Contract.Assert(numbericTextBox != null);
if (PartIprRegex.IsMatch(numbericTextBox.Text))
{
var ips = numbericTextBox.Text.Split('.');
if (ips.Length == 1)
{
return;
}
int index = this.numbericTextBoxs.IndexOf(numbericTextBox);
int pointer2Ips = 0;
for (int i = index; i < this.numbericTextBoxs.Count; i++)
{
while (pointer2Ips < ips.Length && string.IsNullOrEmpty(ips[pointer2Ips]))
{
pointer2Ips++;
}
if (pointer2Ips >= ips.Length)
{
return;
}
this.numbericTextBoxs[i].Text = ips[pointer2Ips];
pointer2Ips++;
}
}
}
private void TextBoxBase_OnTextChanged(object sender, TextChangedEventArgs e)
{
var ip = string.Format(
"{0}.{1}.{2}.{3}",
this.IPPart1.Text,
this.IPPart2.Text,
this.IPPart3.Text,
this.IPPart4.Text);
if (IpRegex.IsMatch(ip))
{
this.IP = ip;
}
}
#endregion Event Handling
}
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