将代码从C＃转换为VB时会感到困惑... [英] Confused when converting code from C# to VB...

问题描述

大家好，我正在将一些C＃代码转换为VB并且我几乎已经完成了b $ b，但这最后一点让我感到困惑。


我正在尝试转换以下C＃代码...


公共事件EventHandler< EnterKeyEventArgsEnterKeyEvent;


private void Body_KeyDown（object sender，HtmlElementEventArgs e）

{

if（e.KeyPressedCode == 13&&！e.ShiftKeyPressed）

{

//处理输入代码取消

bool cancel = false;

if（EnterKeyEvent！= null）

{

EnterKeyEventArgs args = new EnterKeyEventArgs（）;

EnterKeyEvent（this，args）;

cancel = args.Cancel;

}

e.ReturnValue =！取消;

}

}


进入VB，到目前为止我有...


公共事件EnterKeyEvent As EventHandler（Of EnterKeyEventArgs）


私有子Body_KeyDown（ByVal发送者为Ob ject，ByVal e As

HtmlElementEventArgs）


如果e.KeyPressedCode = 13而且也不是e.ShiftKeyPressed那么

Dim取消As Boolean = False

如果不是IsNothing（EnterKeyEvent）那么''问题行

Dim args As New EnterKeyEventArgs（）

RaiseEvent EnterKeyEvent（Me， args）

cancel = args.Cancel

结束如果

e.ReturnValue =不取消

结束如果< br $>

结束子


上面的VB部分有一行注释PROBLEM LINE

在末尾。 Visual Studio给出了以下错误...


"

''公共事件EnterKeyEvent（发送者为对象，e为EnterKeyEventArgs）''

是一个事件，不能直接调用。使用''RaiseEvent''

语句来举办活动

"


我以为这是在检查活动而不是试图筹集一个？

如果有人知道我应该怎么做，我将非常感激！


Karl

解决方案

" Karl Rhodes" < go ********** @ cortexa.co.ukschrieb：

If Not IsNothing（EnterKeyEvent）Then''PROBLEM LINE

Dim args As New EnterKeyEventArgs（）

RaiseEvent EnterKeyEvent（Me，args）

cancel = args.Cancel

结束If

只需删除无的检查。如果代表被附加，''RaiseEvent''只会提高

事件，遗憾的是没有在C＃中完成。


-

MS Herfried K. Wagner

MVP< URL：http：//dotnet.mvps.org/>

VB< URL：http：// dotnet.mvps.org/dotnet/faqs/>

8月13日，22：43，Herfried K. Wagner [MVP]" < hirf-spam-me-

h ... @ gmx.atwrote：

" Karl Rhodes" < googlegro ... @ cortexa.co.ukschrieb：

If Not IsNothing（EnterKeyEvent）Then''PROBLEM LINE

Dim args作为New EnterKeyEventArgs（）

RaiseEvent EnterKeyEvent（Me，args）

cancel = args.Cancel

结束如果

只需删除没有的检查。如果代表被附加，''RaiseEvent''只会提高

事件，遗憾的是没有在C＃中完成。


-

MS Herfried K. Wagner

MVP< URL：http：//dotnet.mvps.org/>

VB< URL：http：// dotnet.mvps.org/dotnet/faqs/>

嗨Herfried，


我担心它没有任何区别。我把这行改为

两个如果EnterKeyEvent然后和If（EnterKeyEvent）然后我仍然

有同样的错误...


您是否完全删除了if语句？


Karl

" Karl Rhodes" < go ********** @ cortexa.co.ukschrieb：

If Not IsNothing（EnterKeyEvent）然后''问题行

Dim args As New EnterKeyEventArgs（）

RaiseEvent EnterKeyEvent（Me，args）

cancel = args.Cancel

结束如果

只需删除没有的检查。如果代表被附加，''RaiseEvent''只会引发
事件，遗憾的是，这不会在C＃中完成。

我担心它没有任何区别。我把这行改为

两个如果EnterKeyEvent然后和If（EnterKeyEvent）然后我仍然

有同样的错误...


您是否完全删除了if语句？

是的，VB中根本不需要它。


-

MS Herfried K. Wagner

MVP< URL：http：//dotnet.mvps.org/>

VB< URL：http：// dotnet。 mvps.org/dotnet/faqs/>

Hi all, I''m in the middle of converting some C# code to VB and I''m
almost done, but this last little bit is confusing me.

I''m trying to convert the following C# code...

public event EventHandler<EnterKeyEventArgsEnterKeyEvent;

private void Body_KeyDown(object sender, HtmlElementEventArgs e)
{
if (e.KeyPressedCode == 13 && !e.ShiftKeyPressed)
{
// handle enter code cancellation
bool cancel = false;
if (EnterKeyEvent != null)
{
EnterKeyEventArgs args = new EnterKeyEventArgs();
EnterKeyEvent(this, args);
cancel = args.Cancel;
}
e.ReturnValue = !cancel;
}
}

into VB, and so far I have...

Public Event EnterKeyEvent As EventHandler(Of EnterKeyEventArgs)

Private Sub Body_KeyDown(ByVal sender As Object, ByVal e As
HtmlElementEventArgs)

If e.KeyPressedCode = 13 AndAlso Not e.ShiftKeyPressed Then
Dim cancel As Boolean = False
If Not IsNothing(EnterKeyEvent) Then ''PROBLEM LINE
Dim args As New EnterKeyEventArgs()
RaiseEvent EnterKeyEvent(Me, args)
cancel = args.Cancel
End If
e.ReturnValue = Not cancel
End If

End Sub

There is a line in the VB section above with a comment "PROBLEM LINE"
at the end. Visual Studio gives me the following error...

"
''Public Event EnterKeyEvent(sender as Object, e as EnterKeyEventArgs)''
is an event, and cannot be called directly. Use a ''RaiseEvent''
statement to raise an event
"

I thought this was checking for an event and not trying to raise one?
If anyone know''s how I should do this I would be most grateful!

Karl

解决方案

"Karl Rhodes" <go**********@cortexa.co.ukschrieb:

If Not IsNothing(EnterKeyEvent) Then ''PROBLEM LINE
Dim args As New EnterKeyEventArgs()
RaiseEvent EnterKeyEvent(Me, args)
cancel = args.Cancel
End If

Simply remove the check for ''Nothing''. ''RaiseEvent'' will only raise the
event if delegates are attached, which is unfortunately not done in C#.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

On 13 Aug, 22:43, "Herfried K. Wagner [MVP]" <hirf-spam-me-
[e-mail]:

"Karl Rhodes" <[e-mail]:

If Not IsNothing(EnterKeyEvent) Then ''PROBLEM LINE
Dim args As New EnterKeyEventArgs()
RaiseEvent EnterKeyEvent(Me, args)
cancel = args.Cancel
End If

Simply remove the check for ''Nothing''. ''RaiseEvent'' will only raise the
event if delegates are attached, which is unfortunately not done in C#.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

Hi Herfried,

I''m afraid it hasn''t made any difference. I changed the line to read
both "If EnterKeyEvent Then" and "If (EnterKeyEvent) Then" and I still
have the same error...

Did you mean for me to remove the if statement altogether?

Karl

"Karl Rhodes" <go**********@cortexa.co.ukschrieb:

If Not IsNothing(EnterKeyEvent) Then ''PROBLEM LINE
Dim args As New EnterKeyEventArgs()
RaiseEvent EnterKeyEvent(Me, args)
cancel = args.Cancel
End If

Simply remove the check for ''Nothing''. ''RaiseEvent'' will only raise the
event if delegates are attached, which is unfortunately not done in C#.

I''m afraid it hasn''t made any difference. I changed the line to read
both "If EnterKeyEvent Then" and "If (EnterKeyEvent) Then" and I still
have the same error...

Did you mean for me to remove the if statement altogether?

Yes, it''s not required at all in VB.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

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