unable to set DataFormatStrin g (in code) on GridView with AutoGenerateCol umns

[Tim Mackey]

hi,
with a derived DataGrid control, i can override the CreateColumnSet method
and scan into the DataGridColumns and set the DataFormatStrin g, e.g. leave
out the time part of a DateTime value. this works great for a DataGrid
control.

however i'm upgrading this control to inherit from GridView. there seems to
be a limitation of the gridview "Method not supported" when you try and set
a DataFormatStrin g on an AutoGeneratedFi eld.

here's the code:
[ToolboxData("<{ 0}:SmartGridVie w runat=server></{0}:SmartGridVi ew>")]
public class SmartGridView : GridView
{
public SmartGridView()
{
}

protected override ICollection CreateColumns(P agedDataSource dataSource,
bool useDataSource)
{
ArrayList arr = (ArrayList)base .CreateColumns( dataSource, useDataSource);
foreach (AutoGeneratedF ield f in arr)
f.DataFormatStr ing = "{0:dd/MM/yyyy}"; // throws exception
return arr;
}
}

here's the exception:

[NotSupportedExc eption: Specified method is not supported.]
System.Web.UI.W ebControls.Auto GeneratedField. set_DataFormatS tring(String
value) +1839359
SmartGridView.C reateColumns(Pa gedDataSource dataSource, Boolean
useDataSource)

it makes no difference if i cast the AutoGeneratedFi eld to a BoundField.
does anyone know how you can do this? seems strange that the GridView would
lose some features of the DataGrid.

thanks in advance
tim

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Tim,

Unfortunatelly, this property is overriden and can only be set internally
when
_suppressProper tyThrows field is set to true:

public override string DataFormatStrin g
{
get
{
return base.DataFormat String;
}
set
{
if (!this._suppres sPropertyThrows )
{
throw new NotSupportedExc eption();
}
}
}

Which is quite logical as the AutoGeneratedFi eld class is a sealed wrapper
around the BoundField class introduced to represent nonchangable field. There
are two ways you could overcome the problem:
1. use reflection to change value of the _suppressProper tyThrows field (not
recommended
2. (recommended) override
CreateAutoGener atedColumns(Pag edDataSource dataSource) and/or
CreateAutoGener atedColumn(Auto GeneratedFieldP roperties fieldProperties )
methods to provide AutoGeneratedFi eld with DataFormatStrin g set as needed.
In addition to taht, download very powerful tool called Reflector:
http://www.aisto.com/roeder/dotnet/
so you can see the Grid's View code yourself (as well as any other class
from any assembly).

HTH

--
Milosz
"Tim Mackey" wrote:

hi,
with a derived DataGrid control, i can override the CreateColumnSet method
and scan into the DataGridColumns and set the DataFormatStrin g, e.g. leave
out the time part of a DateTime value. this works great for a DataGrid
control.

however i'm upgrading this control to inherit from GridView. there seems to
be a limitation of the gridview "Method not supported" when you try and set
a DataFormatStrin g on an AutoGeneratedFi eld.

here's the code:
[ToolboxData("<{ 0}:SmartGridVie w runat=server></{0}:SmartGridVi ew>")]
public class SmartGridView : GridView
{
public SmartGridView()
{
}

protected override ICollection CreateColumns(P agedDataSource dataSource,
bool useDataSource)
{
ArrayList arr = (ArrayList)base .CreateColumns( dataSource, useDataSource);
foreach (AutoGeneratedF ield f in arr)
f.DataFormatStr ing = "{0:dd/MM/yyyy}"; // throws exception
return arr;
}
}

here's the exception:

[NotSupportedExc eption: Specified method is not supported.]
System.Web.UI.W ebControls.Auto GeneratedField. set_DataFormatS tring(String
value) +1839359
SmartGridView.C reateColumns(Pa gedDataSource dataSource, Boolean
useDataSource)

it makes no difference if i cast the AutoGeneratedFi eld to a BoundField.
does anyone know how you can do this? seems strange that the GridView would
lose some features of the DataGrid.

thanks in advance
tim

[Walter Wang [MSFT]]

Thanks Milosz for your informative input.

Hi Tim,

Thanks for your feedback. Indeed this is by design behavior of the auto
generated field. You can use a BoundField instead and set the
DataFormatStrin g.

Please kindly submit your feedback here which is monitored by our product
group:

http://connect.microsoft.com/Main/co...ContentID=2220

In this way, customers like you who have similiar requirement can vote on a
feedback and raise priority of such feature request.

Please feel free to let me know if there's anything else I can help.
Regards,
Walter Wang (wa****@online. microsoft.com, remove 'online.')
Microsoft Online Community Support

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[Tim Mackey]

hi Walter,
thanks for the follow up. maybe i didn't make clear that i'm doing this
programatically , the only ASPX available is
<cc1:SmartGri d runat="server" id="SmartGrid1 " /so there are no BoundFields
declared in the markup. also, i tried casting the AutoGeneratedFi eld to a
BoundColumn but it makes no difference, you still get the exception.
if you inspect the items in the ArrayList in my code, they are indeed
AutoGeneratedFi eld objects.

any ideas?
thanks
tim

[Walter Wang [MSFT]]

Hi Tim,

Sorry for the misunderstandin g.

In this case, since you're creating a customized GridView control and you
need to control each field's DataFormatStrin g, regardless if the field is
auto-generated or not, not being able to set DataFormatStrin g of
AutoGeneratedFi eld does look too restrictive. I've recorded your feature
request and forwarded to product group. In the meanwhile, you're encouraged
to submit this at
http://connect.microsoft.com/Main/co...ContentID=2220 so
that you can get prompt response when product group responses.

In the meanwhile, although not recommended and supported (as Milosz already
pointed out, thanks), you could use reflection to change it:

#Siderite Zackwehdex's Blog: How to format your GridView autogenerated
columns
http://siderite.blogspot.com/2006/09...-gridview.html

Regards,
Walter Wang (wa****@online. microsoft.com, remove 'online.')
Microsoft Online Community Support

=============== =============== =============== =====
When responding to posts, please "Reply to Group" via your newsreader so
that others may learn and benefit from your issue.
=============== =============== =============== =====

This posting is provided "AS IS" with no warranties, and confers no rights.

[Tim Mackey]

hi milosz, thanks for sharing this tip, i tried your code and it works
great.
thanks for the follow up walter, i'll do the MS connect thing.
thanks
tim
""Walter Wang [MSFT]"" <wa****@online. microsoft.comwr ote in message
news:Yu******** *****@TK2MSFTNG HUB02.phx.gbl.. .

Hi Tim,

Sorry for the misunderstandin g.

In this case, since you're creating a customized GridView control and you
need to control each field's DataFormatStrin g, regardless if the field is
auto-generated or not, not being able to set DataFormatStrin g of
AutoGeneratedFi eld does look too restrictive. I've recorded your feature
request and forwarded to product group. In the meanwhile, you're
encouraged
to submit this at
http://connect.microsoft.com/Main/co...ContentID=2220 so
that you can get prompt response when product group responses.

In the meanwhile, although not recommended and supported (as Milosz
already
pointed out, thanks), you could use reflection to change it:

#Siderite Zackwehdex's Blog: How to format your GridView autogenerated
columns
http://siderite.blogspot.com/2006/09...-gridview.html

Regards,
Walter Wang (wa****@online. microsoft.com, remove 'online.')
Microsoft Online Community Support

=============== =============== =============== =====
When responding to posts, please "Reply to Group" via your newsreader so
that others may learn and benefit from your issue.
=============== =============== =============== =====

This posting is provided "AS IS" with no warranties, and confers no
rights.