Question

这是我的功能（已更新）：

Public Shared Function shortenUrl(ByVal URL As String) As String
    Return shortenUrl(URL, 32)
End Function
Public Shared Function shortenUrl(ByVal URL As String, ByVal maxLength As Integer) As String
    If URL.Length > maxLength Then
        String.Format("{0}...{1}", URL.Substring(0, (maxLength / 2)), URL.Substring(URL.Length - ((maxLength / 2) - 3)))
    Else
        Return URL
    End If
End Function

我修复了它没有返回maxLength个字符的问题，因为它没有考虑省略号。

在我看来，它太复杂了;任何建议，评论和关注都非常受欢迎。

Answer 1

为什么不这样做？

Public Shared Function shortenUrl(ByVal URL As String) As String
    Return shortenUrl(URL, 29)
End Function
Public Shared Function shortenUrl(ByVal URL As String, ByVal maxLength As Integer) As String
    If URL.Length > maxLength Then
        Return String.Format("{0}...{1}", URL.Substring(0, maxLength / 2),URL.Substring(URL.Length - (maxLength / 2)))
    Else
        Return URL
    End If
End Function

至少可以摆脱所有的暂时声明

Answer 2

嗯，我不知道它是否太复杂......但这是错误的。如果我调用shortenUrl（URL，29），我希望返回的最大长度为29个字符。你的代码会给我31.如果我用30的长度调用它，我会得到33个字符。你没有包括插入的“...”，你依靠舍入来获得子串长度并删除其余部分。

我会添加一些参数验证，并将其更改为：

Public Function shortenUrl2(ByVal URL As String, ByVal maxLength As Integer) As String
    Const middle as String = "..."
    If maxLength < 0 Then
       Throw New ArgumentOutOfRangeException("maxLength", "must be greater than or equal to 0")
    ElseIf String.IsNullOrEmpty(URL) OrElse URL.Length <= maxLength Then
       Return URL
    ElseIf maxLength < middle.Length Then
       Return URL.Substring(0, maxLength)
    End If

    Dim left as String = URL.Substring(0, CType(Math.Floor(maxLength / 2), Integer))
    Dim right as String = URL.Substring(URL.Length - (maxLength - left.Length - middle.Length))

    Return left & middle & right
End Function

Answer 3

Public Shared Function shortenUrl(ByVal URL As String, Optional ByVal maxLength As Integer = 29) As String
    If URL.Length > maxLength Then       
        Return String.Format("{0}...{1}", URL.Substring(0, maxLength / 2), URL.Substring(URL.Length - (maxLength / 2)))
    Else
        Return URL
    End If
End Function

不确定为什么人们如此讨厌可选参数。他们执行完全相同的操作和向用户公开如果他们不提供默认值，将默认值。

建议改进VB.NET URL缩短器？

3 个答案: