GridView\CheckBox

[gh]

I am using VS 2008. I have a gridview with several columns that are
checkboxes. The data for each column is either a 1 or 0. When I try to
view the page in the browser I get an error "Specified cast is not
valid". Below is the code for the column. PL is the field name in the
datasource. It is a string field. I did change it to integer and still
received the same error message. What could be causing the error?


TIA



<asp:TemplateFi eld>
<EditItemTempla te>
asp:CheckBox ID="CheckBox1" runat="server" Checked='<%#
Bind("PL") %>' />
</EditItemTemplat e>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%#
Bind("PL") %>'
Enabled="false" />
</ItemTemplate>

[Mark Rae [MVP]]

Re: GridView\CheckB ox

"gh" <gh@att.netwrot e in message
news:eTvADQnuIH A.420@TK2MSFTNG P02.phx.gbl...

What could be causing the error?

The Checked tag of an <asp:CheckBox /webcontrol needs to be populated with
something that can be evaluated as a Boolean.

What happens if you modify your markup like so..?

Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'


--
Mark Rae
ASP.NET MVP

http://www.markrae.net

[gh]

Re: GridView\CheckB ox

Mark Rae [MVP] wrote:

"gh" <gh@att.netwrot e in message
news:eTvADQnuIH A.420@TK2MSFTNG P02.phx.gbl...
>

>What could be causing the error?

>
The Checked tag of an <asp:CheckBox /webcontrol needs to be populated
with something that can be evaluated as a Boolean.
>
What happens if you modify your markup like so..?
>
Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
>
>

Mark:

I get the same error message (System.Invalid CastException: Specified
cast is not valid.
) on Line 26.

</EditItemTemplat e>
Line 25: <ItemTemplate >
Line 26: <asp:CheckBox ID="CheckBox1"
runat="server" Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
Line 27: Enabled="false" />
Line 28: </ItemTemplate>

Thanks

[Mark Rae [MVP]]

Re: GridView\CheckB ox

"gh" <gh@att.netwrot e in message
news:OY8g92nuIH A.2068@TK2MSFTN GP05.phx.gbl...

>>What could be causing the error?

>>
>The Checked tag of an <asp:CheckBox /webcontrol needs to be populated
>with something that can be evaluated as a Boolean.
>>
>What happens if you modify your markup like so..?
>>
>Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
>>
>>

Mark:
>
I get the same error message (System.Invalid CastException: Specified cast
is not valid.) on Line 26.
>
</EditItemTemplat e>
Line 25: <ItemTemplate >
Line 26: <asp:CheckBox ID="CheckBox1"
runat="server" Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
Line 27: Enabled="false" />
Line 28: </ItemTemplate>

OK. What *precisely* is the value of "PL" out of the database, and what is
the datatype?

For this to work, it will need to be a datatype / value combination which
can be converted into a Boolean...


--
Mark Rae
ASP.NET MVP

http://www.markrae.net

[gh]

Re: GridView\CheckB ox

Mark Rae [MVP] wrote:

"gh" <gh@att.netwrot e in message
news:OY8g92nuIH A.2068@TK2MSFTN GP05.phx.gbl...
>

>>>What could be causing the error?
>>>
>>The Checked tag of an <asp:CheckBox /webcontrol needs to be
>>populated with something that can be evaluated as a Boolean.
>>>
>>What happens if you modify your markup like so..?
>>>
>>Checked='<% # DataBinder.Eval (Container.Data Item, "PL") %>'
>>>
>>>

>Mark:
>>
>I get the same error message (System.Invalid CastException: Specified
>cast is not valid.) on Line 26.
>>
> </EditItemTemplat e>
>Line 25: <ItemTemplate >
>Line 26: <asp:CheckBox ID="CheckBox1"
>runat="serve r" Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
>Line 27: Enabled="false" />
>Line 28: </ItemTemplate>

>
OK. What *precisely* is the value of "PL" out of the database, and what
is the datatype?
>
For this to work, it will need to be a datatype / value combination
which can be converted into a Boolean...
>
>

It is a varchar. The value is 0 or 1. I tried a Convert.ToInt32 , but
receeved an error about the bool value. I don' t control the table
structures and have to use what is given to me. Shouldn' t an integer 1
or 0 be evaluated as a bool?

Thanks

[Mark Rae [MVP]]

Re: GridView\CheckB ox

"gh" <gh@att.netwrot e in message
news:OxcVZIouIH A.4876@TK2MSFTN GP02.phx.gbl...

>OK. What *precisely* is the value of "PL" out of the database, and what
>is the datatype?
>>
>For this to work, it will need to be a datatype / value combination which
>can be converted into a Boolean...
>>

It is a varchar. The value is 0 or 1.

OK, well that's *never* going to work natively as you've already discovered.

I tried a Convert.ToInt32 , but receeved an error about the bool value. I
don' t control the table structures and have to use what is given to me.

Hmm - OK... Where did you do the Convert.ToInt32 ?

Shouldn' t an integer 1 or 0 be evaluated as a bool?

Yes it should - which is why I'm wondering where you did the conversion...


--
Mark Rae
ASP.NET MVP

http://www.markrae.net

[gh]

Re: GridView\CheckB ox

Mark Rae [MVP] wrote:

"gh" <gh@att.netwrot e in message
news:OxcVZIouIH A.4876@TK2MSFTN GP02.phx.gbl...
>

>>OK. What *precisely* is the value of "PL" out of the database, and
>>what is the datatype?
>>>
>>For this to work, it will need to be a datatype / value combination
>>which can be converted into a Boolean...
>>>

>It is a varchar. The value is 0 or 1.

>
OK, well that's *never* going to work natively as you've already
discovered.
>

>I tried a Convert.ToInt32 , but receeved an error about the bool
>value. I don' t control the table structures and have to use what is
>given to me.

>
Hmm - OK... Where did you do the Convert.ToInt32 ?
>

>Shouldn' t an integer 1 or 0 be evaluated as a bool?

>
Yes it should - which is why I'm wondering where you did the conversion...
>
>

<asp:TemplateFi eld>
<EditItemTempla te>
<asp:CheckBox ID="CheckBox1" runat="server"
Checked='<%# Convert.ToInt32 (DataBinder.Eva l(Container.Dat aItem, "PL"))
%>' />
</EditItemTemplat e>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server"
Checked='<%# Convert.ToInt32 (DataBinder.Eva l(Container.Dat aItem, "PL"))
%>'
Enabled="false" />
</ItemTemplate>

Thanks

[Mark Rae [MVP]]

Re: GridView\CheckB ox

"gh" <gh@att.netwrot e in message
news:eoGJLiouIH A.5288@TK2MSFTN GP06.phx.gbl...

>Yes it should - which is why I'm wondering where you did the
>conversion.. .

>
<asp:TemplateFi eld>
<EditItemTempla te>
<asp:CheckBox ID="CheckBox1" runat="server"
Checked='<%# Convert.ToInt32 (DataBinder.Eva l(Container.Dat aItem, "PL"))
%>' />
</EditItemTemplat e>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server"
Checked='<%# Convert.ToInt32 (DataBinder.Eva l(Container.Dat aItem, "PL"))
%>'
Enabled="false" />
</ItemTemplate>

OK, indulge me...

Change the above to the code below, and tell me what the Text shows next to
the CheckBoxes...

<asp:TemplateFi eld>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%#
DataBinder.Eval (Container.Data Item, "PL") %>' Enabled="false" />
</ItemTemplate>
</ asp:TemplateFie ld>


--
Mark Rae
ASP.NET MVP

http://www.markrae.net

[Mark Rae [MVP]]

Re: GridView\CheckB ox

"Mark Rae [MVP]" <mark@markNOSPA Mrae.netwrote in message
news:%23r0mLyou IHA.3680@TK2MSF TNGP05.phx.gbl. ..

<asp:TemplateFi eld>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%#
DataBinder.Eval (Container.Data Item, "PL") %>' Enabled="false" />
</ItemTemplate>
</ asp:TemplateFie ld>

Apologies - I meant this:

<asp:TemplateFi eld>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server" Text='<%#
DataBinder.Eval (Container.Data Item, "PL") %>' />
</ItemTemplate>
</ asp:TemplateFie ld>



--
Mark Rae
ASP.NET MVP

http://www.markrae.net

[=?Utf-8?B?YnJ1Y2UgYmFya2Vy?=]

Re: GridView\CheckB ox

as stated the "checked" value needs to be a bool. so:

Checked='<%# DataBinder.Eval (Container.Data Item, "PL").ToString( ) == "1" %>'

will work.

-- bruce (sqlwork.com)


"gh" wrote:

Mark Rae [MVP] wrote:

"gh" <gh@att.netwrot e in message
news:OY8g92nuIH A.2068@TK2MSFTN GP05.phx.gbl...

>>What could be causing the error?
>>
>The Checked tag of an <asp:CheckBox /webcontrol needs to be
>populated with something that can be evaluated as a Boolean.
>>
>What happens if you modify your markup like so..?
>>
>Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
>>
>>
Mark:
>
I get the same error message (System.Invalid CastException: Specified
cast is not valid.) on Line 26.
>
</EditItemTemplat e>
Line 25: <ItemTemplate >
Line 26: <asp:CheckBox ID="CheckBox1"
runat="server" Checked='<%# DataBinder.Eval (Container.Data Item, "PL") %>'
Line 27: Enabled="false" />
Line 28: </ItemTemplate>

OK. What *precisely* is the value of "PL" out of the database, and what
is the datatype?

For this to work, it will need to be a datatype / value combination
which can be converted into a Boolean...

It is a varchar. The value is 0 or 1. I tried a Convert.ToInt32 , but
receeved an error about the bool value. I don' t control the table
structures and have to use what is given to me. Shouldn' t an integer 1
or 0 be evaluated as a bool?
>
Thanks
>

[gh]

Re: GridView\CheckB ox

Mark Rae [MVP] wrote:

"Mark Rae [MVP]" <mark@markNOSPA Mrae.netwrote in message
news:%23r0mLyou IHA.3680@TK2MSF TNGP05.phx.gbl. ..
>

><asp:TemplateF ield>
> <ItemTemplate >
> <asp:CheckBox ID="CheckBox1" runat="server" Checked='<%#
>DataBinder.Eva l(Container.Dat aItem, "PL") %>' Enabled="false" />
> </ItemTemplate>
></ asp:TemplateFie ld>

>
Apologies - I meant this:
>
<asp:TemplateFi eld>
<ItemTemplate >
<asp:CheckBox ID="CheckBox1" runat="server" Text='<%#
DataBinder.Eval (Container.Data Item, "PL") %>' />
</ItemTemplate>
</ asp:TemplateFie ld>
>
>
>

Mark:

I have it working using the suggested markup:

Checked='<%# DataBinder.Eval (Container.Data Item, "PL").ToString( ) ==
"1" %>'.

Thanks