如何检查字符串是否仅包含数字、字母或空格?
如何检查字符串是否仅包含数字、字母或空格?
C# 中这很简单:
private bool HasSpecialChars(string yourString)
{
return yourString.Any(ch => ! char.IsLetterOrDigit(ch));
}
最简单的方法是使用正则表达式:
在.NET中使用正则表达式:
http://www.regular-expressions.info/dotnet.html
var regexItem = new Regex("^[a-zA-Z0-9 ]*$");
if(regexItem.IsMatch(YOUR_STRING)){..}
public static bool ContainsOnlyAlphaNumericCharacters(this string inputString)
{
var regexItem = new Regex("^[a-zA-Z0-9 ]*$");
return regexItem.IsMatch(inputString);
}
- vibs2006试试这个方法。
public static bool hasSpecialChar(string input)
{
string specialChar = @"\|!#$%&/()=?»«@£§€{}.-;'<>_,";
foreach (var item in specialChar)
{
if (input.Contains(item)) return true;
}
return false;
}
string s = @"$KUH% I*$)OFNlkfn$";
var withoutSpecial = new string(s.Where(c => Char.IsLetterOrDigit(c)
|| Char.IsWhiteSpace(c)).ToArray());
if (s != withoutSpecial)
{
Console.WriteLine("String contains special chars");
}
String test_string = "tesintg#$234524@#";
if (System.Text.RegularExpressions.Regex.IsMatch(test_string, "^[a-zA-Z0-9\x20]+$"))
{
// Good-to-go
}
Regex.IsMatch(items, "[a-z0-9 ]+", RegexOptions.IgnoreCase);
使用以下正则表达式验证字符串,以确保它只包含数字、字母或空格:
/^[a-zA-Z0-9\s]+$/
[a-zA-Z0-9 ]
private bool isMatch(string strValue,string specialChars)
{
return specialChars.Where(x => strValue.Contains(x)).Any();
}
你可以使用布尔类型来实现。最近我学到了这种方法。在这个例子中,我正在检查用户在控制台上的输入:
using System;
using System.Linq;
namespace CheckStringContent
{
class Program
{
static void Main(string[] args)
{
//Get a password to check
Console.WriteLine("Please input a Password: ");
string userPassword = Console.ReadLine();
//Check the string
bool symbolCheck = userPassword.Any(p => !char.IsLetterOrDigit(p));
//Write results to console
Console.WriteLine($"Symbols are present: {symbolCheck}");
}
}
}
如果字符串中存在特殊字符(symbolCheck),则返回“True”,如果不存在,则返回“False”。
public void hasSpecialChar(string input)
{
char[] specialChar = {'(',')'};
foreach (char item in specialChar)
{
if (input.Contains(item)) MessageBox.Show("it contains");
}
}
在您的按钮单击事件中,或者您双击按钮两次,就像这样:
private void button1_Click(object sender, EventArgs e)
{
hasSpecialChar(textbox1.Text);
}