Integer.TryParse-更好的方法? [英] Integer.TryParse - a better way?

问题描述

我发现自己经常需要使用Integer.TryParse来测试值是否为整数.但是，当您使用TryParse时，必须将引用变量传递给该函数，因此我发现自己总是需要创建一个空白整数来传递.通常看起来像这样:

I find myself often needing to use Integer.TryParse to test if a value is an integer. However, when you use TryParse, you have to pass a reference variable to the function, so I find myself always needing to create a blank integer to pass in. Usually it looks something like:

Dim tempInt as Integer
If Integer.TryParse(myInt, tempInt) Then

考虑到我想要的只是一个简单的True/False响应，我发现这很麻烦.有没有更好的方法来解决这个问题?为什么没有重载的函数可以传递要测试的值并获得true/false响应?

I find this to be quite cumbersome considering that all I want is a simple True / False response. Is there a better way to approach this? Why isn't there an overloaded function where I can just pass the value I want to test and get a true / false response?

推荐答案

无需声明整数.

If Integer.TryParse(intToCheck, 0) Then

或

If Integer.TryParse(intToCheck, Nothing) Then

---

如果您具有.Net 3.5的功能，则可以为字符串创建扩展方法.

---

If you have .Net 3.5 ability you can create an extension method for strings.

Public Module MyExtensions

    <System.Runtime.CompilerServices.Extension()> _
    Public Function IsInteger(ByVal value As String) As Boolean
        If String.IsNullOrEmpty(value) Then
            Return False
        Else
            Return Integer.TryParse(value, Nothing)
        End If
    End Function

End Module

然后致电:

If value.IsInteger() Then

---

对不起，我不知所措，但是您也可以将其添加到.Net 3.5中的MyExtensions类中，除非您需要验证，不要担心.

---

Sorry, getting carried away I know, but also you can add this to the MyExtensions class above in .Net 3.5 and not worry unless you need validations.

<System.Runtime.CompilerServices.Extension()> _
Public Function ToInteger(ByVal value As String) As Integer
    If value.IsInteger() Then
        Return Integer.Parse(value)
    Else
        Return 0
    End If
End Function

然后只需使用

value.ToInteger()

如果它不是有效的Integer，它将返回0.

This will return 0 if it isn't a valid Integer.

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