Question

有没有办法给多个变量赋值（在这种情况下是整数），而不是一次全部？

例如，我有Dim aceVal, twoVal, threeVal, fourVal, fiveVal, sixVal, sevenVal, eightVal, nineVal, tenVal As Integer，并且在待列表框选择之前，我想将三个值分别设置为四个值和六个值。

我该怎么做？感谢。

Answer 1

我真的不是要成为一个混蛋，但是你有什么理由不能这样做：

threeVal = -1
fourVal = -1
sixVal = -1

Answer 2

在vb.net中无法将它们全部分配到一行，如threeVal = fourVal = SixVal。

如果你需要所有这些变量，那么一次只有一行。我建议如果-1将被大量使用，那么为它创建一个常量并将var赋值给常量。

如果可能的话，我还会考虑使用数组或集合存储所有值，并使用它们来设置/检索它们的值。然后，您的代码中不必包含60个变量。数组和/或集合会更清晰。

Answer 3

您可以像这样使用数组/字典：

Dictionary myValues = new Dictionary();

myValues.Add("FirstVal", 1);
myValues.Add("SecondVal", -1);
myValues.Add("ThirdVal", 1);

然后你可以编写一个简单的函数：

public updateMyValues(string[] myKeys, int myValue)
{
     foreach (string s in myKeys)
        {
            myValues[s] = myValue;
        }
}

最后当你的列表框改变时，你可以调用函数来更新你想要的变量：

upDateMyValues({"FirstVal", "ThirdVal"}, -1);

希望这有帮助。

*编辑：我知道它在C＃中，但它很容易移植到VB。

Answer 4

如果你想把它保持在一行，你就可以这样做

Dim m1 As String = "false", m2 As String = "false", m3 As String = "false" 
'etc..

Answer 5

您可以使用构造函数声明和赋值：

 Dim str1, str2, str3, str4 As New String("asdf")
 Dim int1, int2, int3, int4 As New Integer

Answer 6

我知道这是一个老线程，但我自己也遇到了类似的问题 - 这就是我做的方式（我只处理4个值

Private Sub SetFalse(ByRef first As Boolean, Optional ByRef second As Boolean = False, Optional ByRef third As Boolean = False, Optional ByRef fourth As Boolean = False)
    first = False
    second = False
    third = False
    fourth = False
End Sub

这可以通过使第一个变量成为所需的值来轻松调整（这段代码也看起来有点愚蠢，因为我必须提供一个只能是真或假的默认值，但很明显有整数或者看起来更有意义的东西。）

Answer 7

您可以尝试这样：

Dim aceVal, twoVal,fourVal,sevenVal, eightVal, nineVal, tenVal As Integer
Dim threeVal As Integer =-1,fiveVal=-1,sixVal=-1

或者点击这篇文章：http://www.informit.com/library/content.aspx?b=Net_2003_21days&seqNum=95

Answer 8

您可以将其放入List并使用For Each方法这是代码

Dim aceVal, twoVal, threeVal, fourVal, fiveVal, sixVal, sevenVal, eightVal, nineVal, tenVal As Integer
Dim var As New List(Of Integer) From {threeVal, fiveVal, sixVal} 'you can add more variable here
For Each n As Integer In var
    n = -1
Next

Answer 9

我认为多重赋值功能所以很酷 C＃我写了 VB 扩展方法（ Assign）做同样的事情。语义很容易理解;您只需在任何值上调用Assign即可将其分配给多个其他变量即。

Call True.Assign(b1, b2, b3)
Call 4.1.Assign(d1, d2, d3)

等...

以下是代码：

Imports System.Runtime.CompilerServices


Namespace Utility
    Public Module MultiAssignExtensionMethod
        ' Multiply assign the same value to 1 (required) or more variables
        <Extension()> _
        Public Function Assign(Of T)(this As T, ByRef first As T, Optional ByRef second As T = Nothing, Optional ByRef third As T = Nothing,
                                    Optional ByRef forth As T = Nothing, Optional ByRef fifth As T = Nothing, Optional ByRef sixth As T = Nothing,
                                    Optional ByRef seventh As T = Nothing, Optional ByRef eighth As T = Nothing, Optional ByRef nineth As T = Nothing,
                                    Optional ByRef tenth As T = Nothing) As T
                            ' I would LIKE to do this as a ParamArray, but it doesn't allow references for basic types....grrr
            first = this
            second = this
            third = this
            forth = this
            fifth = this
            sixth = this
            seventh = this
            eighth = this
            nineth = this
            tenth = this

            Return this     ' For use as assignment and evaluation as Function parameter
        End Function
    End Module
End Namespace

多个变量

9 个答案: