C# 正则表达式限制输入

清疚 2023-10-18 19:30 81阅读 0赞

#### Winform 中： ####

建立一个类，方便以后使用，内容如下：

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows.Forms;
    using System.Text.RegularExpressions;
    
    namespace UI
    {
        public class TextSet
        {
            /// <summary>
            /// 限制只可输入数字
            /// </summary>
            /// <param name="e"></param>
            public static void setNumber(KeyPressEventArgs e)
            {
                if (e.KeyChar != '\b' && !Char.IsDigit(e.KeyChar))
                {
                    e.Handled = true;
                    MessageBox.Show("请输入数字！");
                    return;
                }
            }
    
            /// <summary>
            /// 限制只能输入汉字或字母
            /// </summary>
            /// <param name="c"></param>
            public static void setChinese(KeyPressEventArgs e)
            {
                Regex rg = new Regex(@"^[\u4e00-\u9fa5a-zA-Z\b]+$"); //\b是退格键
                if (!rg.IsMatch(e.KeyChar.ToString()))
                {
                    e.Handled = true;
                    MessageBox.Show("只能输入汉字或字母！");
                    return;
                }
            }
    
            /// <summary>
            /// 只能输入字母或数字
            /// </summary>
            /// <param name="e"></param>
            public static void setEnglishOrNum(KeyPressEventArgs e)
            {
                if ((e.KeyChar >= 'a' && e.KeyChar <= 'z') || (e.KeyChar >= 'A' && e.KeyChar <= 'Z')
       || (e.KeyChar >= '0' && e.KeyChar <= '9') || (e.KeyChar == 8))
                {
                    e.Handled = false;
    
                }
                else
                {
                    e.Handled = true;
                    MessageBox.Show("密码只能是字母或者数字！");
                    return;
                }
    
            }
        }
    }

针对 Textbox 中的事件：

private void txtUserID_KeyPress(object sender, KeyPressEventArgs e)
        {
            TextSet.setNumber(e);
        }

#### WPF 中： ####

建立一个类，方便以后使用，内容如下：

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Text.RegularExpressions;
    using System.Threading.Tasks;
    using System.Windows.Input;
    
    namespace UI
    {
        public class Limit
        {
            /// <summary>
            /// 限制只能输入数字
            /// </summary>
            /// <param name="e"></param>
            public void limitnumber(TextCompositionEventArgs e)
            {
                Regex re = new Regex("[^0-9]+");
    
                e.Handled = re.IsMatch(e.Text);
            }
    
            /// <summary>
            /// 限制只能输入数字1到7
            /// </summary>
            /// <param name="e"></param>
            public bool limitnumberOneToServen(TextCompositionEventArgs e)
            {
                Regex re = new Regex("[^1-7]+");
    
                e.Handled = re.IsMatch(e.Text);
    
                return e.Handled;
            }
    
            /// <summary>
            /// 限制只能输入数字和小数点
            /// </summary>
            /// <param name="e"></param>
            public void limitnumber1(TextCompositionEventArgs e)
            {
                Regex re = new Regex("[^0-9.]+");
    
                e.Handled = re.IsMatch(e.Text);
            }
        }
    }

针对 Textbox 中的事件：

private void TxtBoxID_PreviewTextInput(object sender, TextCompositionEventArgs e)
            {
                Limit limit = new Limit();
                limit.limitnumber(e);
            }

> 代码按需更改

#### 推荐阅读 ####

[Regex Class (System.Text.RegularExpressions)][Regex Class _System.Text.RegularExpressions]

[Regex Class _System.Text.RegularExpressions]: https://docs.microsoft.com/zh-cn/dotnet/api/system.text.regularexpressions.regex?f1url=https%3A%2F%2Fmsdn.microsoft.com%2Fquery%2Fdev15.query%3FappId%3DDev15IDEF1%26l%3DZH-CN%26k%3Dk%28System.Text.RegularExpressions.Regex%29;k%28TargetFrameworkMoniker-.NETFramework,Version%3Dv4.6.1%29;k%28DevLang-csharp%29%26rd%3Dtrue&view=netframework-4.8