用户名字段必须包含仅包含数字的字符 [英] The username field must contain characters only without number

问题描述

我怎么能这样做..

当我注册用户名时必须只包含字符，



.... ..

i做了这个子并在注册按钮代码中调用它？



我尝试过：

  Sub  TextBox1_TextChanged（）
  Dim  charactersDisallowed  As   String  =   abcdefghijklmnpoqrstuvwxyz 
  Dim  theText  As   String  = TxtUser.Text 
  Dim  Letter < span class =code-keyword> As   String  
 '  Dim SelectionIndex As Integer = TxtUser.S electionStart  
  Dim 更改作为 整数 
 
 对于 x  As  整数 =  0    TxtUser.Text.Length  -   1  
 Letter = TxtUser.Text.Substring（x， 1 ）
 如果 charactersDisallowed.Contains（Letter）那么 
 theText = theText.Replace（Letter， String  .Empty）
更改=  1  
 结束 如果 
 下一步 
 
 TxtUser.Text = theText 
 '  TxtUser.Select（SelectionIndex  -  Change，0） 
 结束  Sub  

解决方案

嗯。

那段代码呃......不同......

如果你只想让字母，那么为什么要把你想要的字母放在charactersDisallowed字符串中呢？ />
而是考虑这个：

  Dim  theText 作为 字符串 = TxtUser.Text 
  Dim  charsAllowed 作为 字符串 =   abcdefghijklmnpoqrstuvwxyz 
  Dim  theNewText  As   String  =   
 对于 每个 c 作为 字符 在 theText 
 如果 charsAllowed.Contains（c）那么 
 theNewText + = c 
 结束 如果 
 下一步 

how I can do this ..
when I registering the user name must to contain characters only,

......
i did this sub and call it in the register button code ??

What I have tried:

Sub TextBox1_TextChanged()
        Dim charactersDisallowed As String = "abcdefghijklmnpoqrstuvwxyz"
        Dim theText As String = TxtUser.Text
        Dim Letter As String
        'Dim SelectionIndex As Integer = TxtUser.SelectionStart
        Dim Change As Integer

        For x As Integer = 0 To TxtUser.Text.Length - 1
            Letter = TxtUser.Text.Substring(x, 1)
            If charactersDisallowed.Contains(Letter) Then
                theText = theText.Replace(Letter, String.Empty)
                Change = 1
            End If
        Next

        TxtUser.Text = theText
        'TxtUser.Select(SelectionIndex - Change, 0)
    End Sub

解决方案

Um.
That code is er...different...
If you want to allow letters only, then why put the letters you want in the "charactersDisallowed" string?
Instead consider this:

Dim theText As String = TxtUser.Text
Dim charsAllowed As String = "abcdefghijklmnpoqrstuvwxyz"
Dim theNewText As String = ""
For Each c As Char In theText
    If charsAllowed.Contains(c) Then
        theNewText += c
    End If
Next

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