如何从vb.net的字符串中删除一个非常特定的部分

Question

我有一个字符串变量，它应该包含如下示例中的值:

Dim xStr as string  = "13,14,133,15,2500,25"

我需要删除一个非常特定的值，比如"13"，但是当我使用替换函数时，我有很多限制，因为如果我替换"13"如果为空，结果将是"， 14,3,15,255,25 "。这是错误的，因为我只需要删除13和它后面的逗号，如果它在那里。

我如何应用它?

Answer 1

我会将字符串分成单独的数字(仍然是字符串)，然后使用Step -1进行反向For循环，这样我们就不会得到超出范围的索引。

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim xStr As String = "13,14,133,15,2500,25"
Dim numToRemove As String = "13"
Dim nums = xStr.Split(","c).ToList
For index = nums.Count - 1 To 0 Step -1
If nums(index) = numToRemove Then
nums.RemoveAt(index)
End If
Next
Dim NewString = String.Join(",", nums)
MessageBox.Show(NewString)
End Sub

Answer 2

嗯，我们必须在这里做一些假设。

但是，一个额外的(偏离的)空格-是的，我们应该处理它。

我们也支持，如果只有一个条目没有逗号是删除号。

所以，这个工作得很好:

Dim strToRemove As String = "14"
Dim str = "13,14 ,133,15,2500,25,"
str = str.Replace(" ", "")
Dim strL As List(Of String) = str.Split(",").ToList
strL.RemoveAll(Function(xRow) xRow = strToRemove)
str = Join(strL.ToArray(), ",")
Debug.Print("<" & str & ">")

输出:

<13,133,15,2500,25,>

以上也适用于"empty"分隔符的值。

如果我们受到惩罚，我们可能会用一行写完整个交易，但我建议如果你经常使用这段代码，那么我们就用这个

Public Function RemoveToken(str as string, sRemove as string) as string
str = str.Replace(" ", "")
Dim strL As List(Of String) = str.Split(",").ToList
strL.RemoveAll(Function(xRow) xRow = sRemove)
return Join(strL.ToArray(), ",")
End Function

Answer 3

试试这个

使用:Replace,TrimStart和TrimEnd方法完成。

'A string sample
Dim xStr as string = "33, 13, , 14  ,133 ,15,  2500 ,25"
'Put a number to remove here
Dim number_to_remove=13
xStr = xStr.Replace(" ","") ' Removing any unnecessary whitespace
xStr=","+xStr+","           ' Adding a padding comma
Console.WriteLine(xStr) 
' Removing wanted number
xStr = xStr.Replace("," + Cstr(number_to_remove) + ","  ,",")
' Removing any unnecessary comma        
if xStr.StartsWith(",") then   ' Remove coma At the beginning
xStr = xStr.trimstart(",")
end if  
if xStr.EndsWith(",") then    ' Remove coma At the end
xStr = xStr.trimend(",")
end if 
xStr = xStr.Replace(",,",",") ' Remove coma in the middle
Console.WriteLine(xStr)     

输入()

注意，输入被处理为容忍spaces和empty元素。

"33, 13, , 14  ,133 ,15,  2500 ,25"

在本例中，要删除的号码是13。

输出()

"33,14,133,15,2500,25"

Answer 4

试试这个:

Dim xStr as string = "13,14,133,15,2500,25"
xStr = xStr.Remove(0, xStr.IndexOf(",") + 1).Trim()