CType不适用于Button [英] CType not working for Button
问题描述
我有以下内容：
sub submitQuestion_click（Sender as Object，e as EventArgs）
Dim submitButton as Button = CType（sender，Button）
这给我一个错误，上面写着：
" System.InvalidCastException：指定的强制转换无效。
为什么会这样？
发件人是一个按钮。
Tom
" tshad" < TS ********** @ ftsolutions.com>在消息中写道
新闻：OB ************** @ TK2MSFTNGP14.phx.gbl ...我有以下内容：
sub submitQuestion_click（发件人作为对象，e作为EventArgs）
将submitButton变暗为Button = CType（发件人，按钮）
这给我一个错误说：
System.InvalidCastException：指定的强制转换无效。
为什么？
发件人是一个按钮。
Tom
尝试这个，如果你仍然无法弄明白，发布结果...
Sub submitQuestion_Click（ByVal Sender As Object，ByVal e As EventArgs）
Response.Write（Sender.GetType（）。ToString（））
End Sub
然后运行应用程序并单击按钮。
如果这没有用，请记得发布打印的内容。
Mythran
试试这个：
Dim submitButton = CType（发件人，按钮）
Jason Bentley
" Mythran" <き******** @ hotmail.comREMOVETRAIL>在消息中写道
news：e5 ************** @ TK2MSFTNGP14.phx.gbl ...
" ; tshad" < TS ********** @ ftsolutions.com>在消息中写道
新闻：OB ************** @ TK2MSFTNGP14.phx.gbl ...我有以下内容：
sub submitQuestion_click（发件人作为对象，e作为EventArgs）
将submitButton作为Button = CType（发件人，按钮）昏暗
这给了我一个错误说：
System.InvalidCastException：指定的强制转换无效。
为什么会这样？
发件人是一个按钮。
Tom
尝试这个，如果你还是无法弄清楚，发布结果......
Sub submitQuestion_Click（ByVal Sender As Object，ByVal e As EventArgs）
Response.Write（Sender.GetType（）。ToString （））
End Sub
然后运行应用程序并单击按钮。
如果这没有帮助，请记得发布打印的内容。
我做到了并得到了结果：
sender type = System.Web.UI.WebControls.Button
Tom
Mythran
I have the following:
sub submitQuestion_click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Button)
This gives me an error that says:
" System.InvalidCastException: Specified cast is not valid. "
Why is that?
Sender is a button.
Tom
"tshad" <ts**********@ftsolutions.com> wrote in message
news:OB**************@TK2MSFTNGP14.phx.gbl...I have the following:
sub submitQuestion_click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Button)
This gives me an error that says:
" System.InvalidCastException: Specified cast is not valid. "
Why is that?
Sender is a button.
Tom
Try this and if you still can''t figure it out, post the results...
Sub submitQuestion_Click(ByVal Sender As Object, ByVal e As EventArgs)
Response.Write(Sender.GetType().ToString())
End Sub
Then run the application and click the button.
If this doesn''t help, remember to post what is printed.
Mythran
Try this:
Dim submitButton = CType(sender, Button)
Jason Bentley
"Mythran" <ki********@hotmail.comREMOVETRAIL> wrote in message
news:e5**************@TK2MSFTNGP14.phx.gbl...
"tshad" <ts**********@ftsolutions.com> wrote in message
news:OB**************@TK2MSFTNGP14.phx.gbl...I have the following:
sub submitQuestion_click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Button)
This gives me an error that says:
" System.InvalidCastException: Specified cast is not valid. "
Why is that?
Sender is a button.
Tom
Try this and if you still can''t figure it out, post the results...
Sub submitQuestion_Click(ByVal Sender As Object, ByVal e As EventArgs)
Response.Write(Sender.GetType().ToString())
End Sub
Then run the application and click the button.
If this doesn''t help, remember to post what is printed.
I did that and got the result:
sender type = System.Web.UI.WebControls.Button
Tom
Mythran
这篇关于CType不适用于Button的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
