为什么这样做？ [英] Why does this work?

问题描述

此代码（Visual Studio 2005）应该通过实例变量（

&）为我正在访问共享成员的

效果生成编译警告;颜色变量：


私人Sub X（ByVal颜色为颜色）

Me.BackColor = color.AliceBlue

结束子


在某些*计算机上，这会产生预期的警告。在其他人身上它确实没有b $ b。有什么设置导致某些计算机无法投诉吗？


TIA - Bob

This code (Visual Studio 2005) should generate a compilation warning to the
effect that I''m accessing a shared member through an instance variable (the
"color" variable):

Private Sub X(ByVal color As Color)
Me.BackColor = color.AliceBlue
End Sub

On *some* computers this produces the expected warning. On others it does
not. Any clue what setting is causing some computers to fail to complain?

TIA - Bob

推荐答案

Vb .net不区分大小写，所以一般来说，有一个名为color

的变量可能不好。


将参数更改为colorparam，然后将行更改为Me.BackColor =

colorparam.AliceBlue，我打赌你到处都会收到警告。


" Bob Altman" < rd*@nospam.nospamwrote in message

news：ur ************** @ TK2MSFTNGP06.phx.gbl ...

Vb.net is not case sensitive, so in general, having a variable called color
could be bad.

Change the parameter to colorparam and then the line to Me.BackColor =
colorparam.AliceBlue, and I bet you get the warning everywhere.

"Bob Altman" <rd*@nospam.nospamwrote in message
news:ur**************@TK2MSFTNGP06.phx.gbl...

此代码（Visual Studio 2005）应该生成一个编译警告

我通过实例变量访问共享成员的效果

（颜色变量）：


私有子X（ByVal颜色为颜色）

Me.BackColor = color.AliceBlue

结束子


在某些*计算机上，这会产生预期的警告。在其他人身上它确实没有b $ b。有什么设置导致某些计算机无法投诉吗？


TIA - Bob

This code (Visual Studio 2005) should generate a compilation warning to
the effect that I''m accessing a shared member through an instance variable
(the "color" variable):

Private Sub X(ByVal color As Color)
Me.BackColor = color.AliceBlue
End Sub

On *some* computers this produces the expected warning. On others it does
not. Any clue what setting is causing some computers to fail to complain?

TIA - Bob

''实例变量访问共享成员''警告是可配置的，因此

在某些机器上设置为Warning，而在其他机器上设置为None。

Bob Altman < rd*@nospam.nospamwrote in message

news：ur ************** @ TK2MSFTNGP06.phx.gbl ...

''Instance variable accesses shared member'' warning is configurable, so
it is set to Warning on some of those machines, and None on the others.
"Bob Altman" <rd*@nospam.nospamwrote in message
news:ur**************@TK2MSFTNGP06.phx.gbl...

此代码（Visual Studio 2005）应该生成一个编译警告

我通过实例变量访问共享成员的效果

（颜色变量）：


私有子X（ByVal颜色为颜色）

Me.BackColor = color.AliceBlue

结束子


在某些*计算机上，这会产生预期的警告。在其他人身上它确实没有b $ b。有什么设置导致某些电脑无法投诉吗？


TIA - Bob

This code (Visual Studio 2005) should generate a compilation warning to
the effect that I''m accessing a shared member through an instance variable
(the "color" variable):

Private Sub X(ByVal color As Color)
Me.BackColor = color.AliceBlue
End Sub

On *some* computers this produces the expected warning. On others it does
not. Any clue what setting is causing some computers to fail to complain?

TIA - Bob

是否得到错误或警告与否取决于特定的

编译器设置（在项目的属性中）。


但实际上，你的代码是不通过实例访问共享成员

变量。


实例变量是您创建实例的变量（隐式或

明确地）并为其分配一个变量 - 你的代码没有这样做，它是b / b
关联一个变量（颜色）来表示一个静态类型。但是，当你用
写color.AliceBlue时，编译器看不到你的大写字母

颜色，它看到你试图访问一个类型的成员

称为颜色并且由于.NET框架中有一个名为

" color"的类型，编译器知道你使用的是颜色的共享成员

类型而不是你的颜色参数名称。


在C＃中，这段代码没有问题，因为它是区分大小写的语言，

但是在VB中它可以使你的代码变得强硬排除故障。正如另一个回复

所说，当命名变量不仅仅是改变这种情况。


-Scott

Bob Altman ; < rd*@nospam.nospamwrote in message

news：ur ************** @ TK2MSFTNGP06.phx.gbl ...

Whether you get an error or warning or not is dependant on that particular
compiler settings (in the project''s properties).

But, actually, you code is NOT accessing a shared member through an instance
variable.

An instance variable is one where you make an instance (implicitly or
explicitly) and assign a variable to it - - your code is not doing that, it
is associating a variable (color) to represent a static type. But, when you
write color.AliceBlue, the compiler doesn''t see your capitalization of
color, it sees that you are attempting to access the members of a type
called "color" and since there is a type in the .NET framework called
"color", the compiler knows you are using the shared members of the color
type and not your color parameter name.

In C#, this code would be no problem since it is a case-sensitive language,
but in VB it can make your code tough to troubleshoot. As the other reply
said, when naming variables do more than change the case.

-Scott
"Bob Altman" <rd*@nospam.nospamwrote in message
news:ur**************@TK2MSFTNGP06.phx.gbl...

此代码（Visual Studio 2005）应该生成一个编译警告

我通过实例变量访问共享成员的效果

（颜色变量）：


私有子X（ByVal颜色为颜色）

Me.BackColor = color.AliceBlue

结束子


在某些*计算机上，这会产生预期的警告。在其他人身上它确实没有b $ b。有什么设置导致某些电脑无法投诉吗？


TIA - Bob

This code (Visual Studio 2005) should generate a compilation warning to
the effect that I''m accessing a shared member through an instance variable
(the "color" variable):

Private Sub X(ByVal color As Color)
Me.BackColor = color.AliceBlue
End Sub

On *some* computers this produces the expected warning. On others it does
not. Any clue what setting is causing some computers to fail to complain?

TIA - Bob

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