最近写winform程序，发现自带的TextBox没发设置输入类型，这就有点痛苦了，查找了网上，没看到比较符合需求的；于是花了点时间，自己自定义了一个简单的数值输入框，实现的方式很简单，继承系统 的TextBox，重写OnTextChanged方法限制输入即可，代码如下：
using System;using System.Collections.Generic;using ponentModel;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace Widgets{/// <summary>/// 数值输入框/// </summary>public class NumberTextBox : TextBox{/// <summary>/// 输入数值类型/// </summary>private NumberType numberType;/// <summary>/// 输入小数点，默认2位/// </summary>private int decimalPointNumber;/// <summary>/// 允许输入的最小值，空值即代表当前类型的最小值/// </summary>private string minValue;/// <summary>/// 允许输入的最大值，空值即代表当前类型的最大值/// </summary>private string maxValue;[Browsable(true)][Category("NumberTextBox"), Description("指定控件数值输入的最小值"), DisplayName("最小值")]public string MinValue{get{return minValue;}set{if (string.IsNullOrWhiteSpace(value)){minValue = "";}else if (numberType == NumberType.Integer){if (int.TryParse(value, out int result)){minValue = result.ToString();}else{minValue = "";}}else if (numberType == NumberType.Long){if (long.TryParse(value, out long result)){minValue = result.ToString();}else{minValue = "";}}else if (numberType == NumberType.Float){if (float.TryParse(value, out float result)){minValue = result.ToString("F" + decimalPointNumber);}else{minValue = "";}}else if (numberType == NumberType.Double){if (double.TryParse(value, out double result)){minValue = result.ToString("F" + decimalPointNumber);}else{minValue = "";}}}}[Browsable(true)][Category("NumberTextBox"), Description("指定控件数值输入的最大值"), DisplayName("最大值")]public string MaxValue{get{return maxValue;}set{if (string.IsNullOrWhiteSpace(value)){maxValue = "";}else if (numberType == NumberType.Integer){if (int.TryParse(value, out int result)){maxValue = result.ToString();}else{maxValue = "";}}else if (numberType == NumberType.Long){if (long.TryParse(value, out long result)){maxValue = result.ToString();}else{maxValue = "";}}else if (numberType == NumberType.Float){if (float.TryParse(value, out float result)){maxValue = result.ToString("F" + decimalPointNumber);}else{maxValue = "";}}else if (numberType == NumberType.Double){if (double.TryParse(value, out double result)){maxValue = result.ToString("F" + decimalPointNumber);}else{maxValue = "";}}}}[Browsable(true)][Category("NumberTextBox"), Description("指定控件数值输入类型"), DisplayName("数值类型")]public NumberType NumberType {get => numberType; set => numberType = value; }[Browsable(true)][Category("NumberTextBox"), Description("当指定输入数值类型为小数时保留小数点位数"), DisplayName("小数点位数")][DefaultValue(2)]public int DecimalPointNumber {get => decimalPointNumber; set => decimalPointNumber = value; }protected override void OnTextChanged(EventArgs e){base.OnTextChanged(e);if (string.IsNullOrWhiteSpace(Text) || Text == "-")//输入负值{return;}switch (numberType){case NumberType.Integer:if (!int.TryParse(Text, out var i)){Text = Text.Substring(0, Text.Length - 1);SelectionStart = Text.Length;}break;case NumberType.Long:if (!long.TryParse(Text, out var l)){Text = Text.Substring(0, Text.Length - 1);SelectionStart = Text.Length;}break;case NumberType.Float:if (!float.TryParse(Text, out var f)){Text = Text.Substring(0, Text.Length - 1);SelectionStart = Text.Length;}break;case NumberType.Double:if (!double.TryParse(Text, out var d)){Text = Text.Substring(0, Text.Length - 1);SelectionStart = Text.Length;}break;}}protected override void OnKeyDown(KeyEventArgs e){base.OnKeyDown(e);if (e.KeyCode == Keys.Enter){VerifyThenFormatValue();}}protected override void OnLostFocus(EventArgs e){base.OnLostFocus(e);VerifyThenFormatValue();}private void VerifyThenFormatValue(){if (string.IsNullOrWhiteSpace(Text)){return;}if (numberType == NumberType.Float){Text = float.Parse(Text).ToString("F" + decimalPointNumber).ToString();}else if (numberType == NumberType.Double){Text = double.Parse(Text).ToString("F" + decimalPointNumber).ToString();}if (!string.IsNullOrWhiteSpace(minValue)){if (numberType == NumberType.Integer){if (int.Parse(Text) < int.Parse(minValue)){Text = minValue;}}else if (numberType == NumberType.Long){if (long.Parse(Text) < long.Parse(minValue)){Text = MinValue;}}else if (numberType == NumberType.Float){if (float.Parse(Text) < float.Parse(minValue)){Text = minValue;}}else if (numberType == NumberType.Double){if (double.Parse(Text) < double.Parse(minValue)){Text = minValue;}}}if (!string.IsNullOrWhiteSpace(maxValue)){if (numberType == NumberType.Integer){if (int.Parse(Text) > int.Parse(maxValue)){Text = maxValue;}}else if (numberType == NumberType.Long){if (long.Parse(Text) > long.Parse(maxValue)){Text = maxValue;}}else if (numberType == NumberType.Float){if (float.Parse(Text) > float.Parse(maxValue)){Text = maxValue;}}else if (numberType == NumberType.Double){if (double.Parse(Text) > double.Parse(maxValue)){Text = maxValue;}}}SelectionStart = Text.Length;}/// <summary>/// 复写Text，确保值是符合我们预设的类型/// </summary>public override string Text {get => base.Text; set {if (string.IsNullOrWhiteSpace(value)){base.Text = value;}else{if (numberType == NumberType.Integer){if (int.TryParse(value,out var result)){base.Text = result.ToString();}else{base.Text = "";}}if (numberType == NumberType.Long){if (long.TryParse(value, out var result)){base.Text = result.ToString();}else{base.Text = "";}}else if (numberType == NumberType.Float){if (float.TryParse(value, out var result)){base.Text = result.ToString("F"+decimalPointNumber);}else{base.Text = "";}}else if (numberType == NumberType.Double){if (double.TryParse(value, out var result)){base.Text = result.ToString("F" + decimalPointNumber);}else{base.Text = "";}}}} }[Browsable(false)][DefaultValue(0)]public int IntValue{get{if (string.IsNullOrWhiteSpace(Text) || numberType != NumberType.Integer){return 0;}VerifyThenFormatValue();return int.Parse(Text);}set{Text = value.ToString();VerifyThenFormatValue();}}[Browsable(false)][DefaultValue(0)]public long LongValue {get{if (string.IsNullOrWhiteSpace(Text) || numberType != NumberType.Long){return 0;}VerifyThenFormatValue();return long.Parse(Text);}set{Text = value.ToString();VerifyThenFormatValue();}}[Browsable(false)][DefaultValue(0)]public float FloatValue{get{if (string.IsNullOrWhiteSpace(Text) || numberType != NumberType.Float){return 0;}VerifyThenFormatValue();return float.Parse(Text);}set{Text = value.ToString();VerifyThenFormatValue();}}[Browsable(false)][DefaultValue(0)]public double DoubleValue{get{if (string.IsNullOrWhiteSpace(Text) || numberType != NumberType.Double){return 0;}VerifyThenFormatValue();return double.Parse(Text);}set{Text = value.ToString();VerifyThenFormatValue();}}}public enum NumberType{Integer, Long, Float, Double}}
该输入框可实现不同类型数值输入，包括整数，小数（可设置保留位数），还可以限制输入的最大最小值
使用方式：
拷贝代码到工程中，编译项目打开工具箱，找到NumberTextBox拖到界面中即可点击控件，可在属性栏中设置输入类型，最大最小值等相关属性根据自己定义的输入类型调用IntValue等方法获取值即可如果觉得《winform 自定义数值(数字)输入框》对你有帮助，请点赞、收藏，并留下你的观点哦！
