可以返回对象和原始数据类型的方法的方法签名... [英] Method Signature For A Method That Can Return Objects and PrimitiveData Types...
问题描述
我是Java开发人员，正在用C＃编写类库，
所以请耐心等待。
我是试图写一个方法，可以返回一个通用的对象或一个
十进制值。在Java中，我只是让方法返回一个Object，因为所有Java原始数据类型都有Object包装器，如Integer
和Double。
如果我有一个在C＃中返回Object的方法签名，我可以在方法体中返回一个
十进制值吗？我正在网上看它
看来Decimal是一个Struct，而不是一个Class，所以我不确定这个
是否合法。
感谢您提供解决方案的帮助。
晒伤测量师
I''m a Java developer in the process of writing a class library in C#,
so please bear with me.
I''m trying to write a method that can return a generic Object OR a
Decimal value. In Java I would just have the method return an Object,
since all Java primitive data types have Object wrappers like Integer
and Double.
If I have a method signature that returns Object in C#, can I return a
Decimal value within the method body? I was looking online at it
appears that Decimal is a Struct, not a Class, so I''m not sure if this
is legal.
Thanks for help with the solution.
The Sunburned Surveyor
推荐答案
2007年12月20日星期四09:57:20 -0800，晒伤的测量师
< su **************** @ gmail.comwrote：
On Thu, 20 Dec 2007 09:57:20 -0800, Sunburned Surveyor
<su****************@gmail.comwrote:
[...]
如果我有一个在C＃中返回Object的方法签名，我可以返回一个
方法体内的十进制值？我在网上看它
看起来十进制是一个结构，而不是一个类，所以我不确定这是否合法。
[...]
If I have a method signature that returns Object in C#, can I return a
Decimal value within the method body? I was looking online at it
appears that Decimal is a Struct, not a Class, so I''m not sure if this
is legal.
它是。
您可能想要阅读拳击，因为返回值类型为
" object"将强制值类型包装在引用类型中
实例（已装箱）。回流到十进制将取消装箱，允许它将
分配给正确值类型的变量（在这种情况下为十进制，当然是
）。
当然，您可以尝试一下它是否有效。 :)
Pete
It is.
You may want to read up on "boxing", as returning a value type as an
"object" will force the value type to be wrapped in a reference type
instance (boxed). Casting back to decimal will unbox it, allowing it to
be assigned to a variable of the correct value type (decimal in this case,
of course).
Of course, you could have just tried it to see if it works. :)
Pete
" Peter Duniho" < Np ********* @nnowslpianmk.com在留言中写道
news：op *************** @ petes-computer.local ...
"Peter Duniho" <Np*********@nnowslpianmk.comwrote in message
news:op***************@petes-computer.local...
2007年12月20日星期四09:57:20 -0800，晒伤测量师
< su **** ************ @ gmail.com写道：
On Thu, 20 Dec 2007 09:57:20 -0800, Sunburned Surveyor
<su****************@gmail.comwrote:
> [...]
如果我有方法签名在C＃中返回Object，我可以在方法体中返回一个十进制值吗？我在网上看它似乎是十进制是一个结构，而不是一个类，所以我不确定这是否合法。
>[...]
If I have a method signature that returns Object in C#, can I return a
Decimal value within the method body? I was looking online at it
appears that Decimal is a Struct, not a Class, so I''m not sure if this
is legal.
它是。
您可能想要阅读拳击，因为返回值类型为
" object"将强制值类型包装在引用类型中
实例（已装箱）。回流到十进制将取消装箱，允许它将
分配给正确值类型的变量（在这种情况下为十进制，当然是
）。
当然，您可以尝试一下它是否有效。 :)
Pete
It is.
You may want to read up on "boxing", as returning a value type as an
"object" will force the value type to be wrapped in a reference type
instance (boxed). Casting back to decimal will unbox it, allowing it to
be assigned to a variable of the correct value type (decimal in this case,
of course).
Of course, you could have just tried it to see if it works. :)
Pete
Pete的优秀建议附录：拳击很慢。
如果你打算经常调用这个方法，你应该认真考虑
只需创建一个新方法。
另一种选择是使用带有out的重载方法。参数
而不是函数结果。当然，这假定您知道结果的
类型。在你打电话给方法之前。
如果我不得不猜测，我会说你写的是某种WinAPI - 函数
如果成功则返回一个对象，如果失败则返回错误代码。在
的情况下，您可以考虑使用out返回小数（0 =成功）和
。成功的参数结果。
An addendum to Pete''s excellent advice: "boxing" is very slow.
If you intend to call this method very often, you should seriously consider
simply creating a new method.
Another option would be to use overloaded methods with an "out" parameter
instead of a function result. This assumes, of course, that you know the
type of the "result" before you call the method.
If I had to guess, I''d say you''re writing some sort of "WinAPI"-ish function
which returns an object if it succeeds and an error code if it fails. In
that case, you might consider always returning a decimal (0 = success) and
using an "out" parameter for your success "result".
12月20日下午12:07，Scott Roberts < srobe ... @ no.spam.here-webworks-
software.comwrote：
On Dec 20, 12:07 pm, "Scott Roberts" <srobe...@no.spam.here-webworks-
software.comwrote:
" Peter Duniho" < NpOeStPe ... @nnowslpianmk.com写在消息中
新闻：op *************** @ petes-computer.local .. 。
"Peter Duniho" <NpOeStPe...@nnowslpianmk.comwrote in message
news:op***************@petes-computer.local...
2007年12月20日星期四09:57:20 -0800，晒伤测量师
< ; sunburned.surve ... @ gmail.comwrote：
On Thu, 20 Dec 2007 09:57:20 -0800, Sunburned Surveyor
<sunburned.surve...@gmail.comwrote:
[...]
如果我有一个在C＃中返回Object的方法签名，我可以在方法体中返回一个
十进制值吗？我在网上看它
看起来十进制是一个结构，而不是一个类，所以我不确定这是否合法。
[...]
If I have a method signature that returns Object in C#, can I return a
Decimal value within the method body? I was looking online at it
appears that Decimal is a Struct, not a Class, so I''m not sure if this
is legal.
它是。
It is.
您可能想要阅读拳击，因为返回值类型为
" object" ;将强制值类型包装在引用类型中
实例（已装箱）。回流到十进制将取消装箱，允许它将
分配给正确值类型的变量（在这种情况下为小数，当然是
）。
You may want to read up on "boxing", as returning a value type as an
"object" will force the value type to be wrapped in a reference type
instance (boxed). Casting back to decimal will unbox it, allowing it to
be assigned to a variable of the correct value type (decimal in this case,
of course).
当然，您可以尝试一下它是否有效。 :)
Of course, you could have just tried it to see if it works. :)
Pete
Pete
对Pete的优秀建议的附录：" ;拳击"很慢。
如果你打算经常调用这个方法，你应该认真考虑
只需创建一个新方法。
另一种选择是使用带有out的重载方法。参数
而不是函数结果。当然，这假定您知道结果的
类型。在你打电话给方法之前。
如果我不得不猜测，我会说你写的是某种WinAPI - 函数
如果成功则返回一个对象，如果失败则返回错误代码。在
的情况下，您可以考虑使用out返回小数（0 =成功）和
。成功的参数结果.-隐藏引用的文字 -
- 显示引用的文字 -
An addendum to Pete''s excellent advice: "boxing" is very slow.
If you intend to call this method very often, you should seriously consider
simply creating a new method.
Another option would be to use overloaded methods with an "out" parameter
instead of a function result. This assumes, of course, that you know the
type of the "result" before you call the method.
If I had to guess, I''d say you''re writing some sort of "WinAPI"-ish function
which returns an object if it succeeds and an error code if it fails. In
that case, you might consider always returning a decimal (0 = success) and
using an "out" parameter for your success "result".- Hide quoted text -
- Show quoted text -
感谢回应斯科特彼得。我实际上是将
方法定义为接口的一部分。在大多数情况下，
这个接口的实现只会从这个特定的
方法返回一个Decimal值。但是，这个界面的偶然实现可能会让b $ b想要从这个方法返回一个自定义对象。
听起来我可能需要提供一个方法对于定制
对象访问。
再次感谢您的帮助。
晒伤的验船师
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