form id, this.Controls ... ?

[Guest]

Hi,

While writing code for creating aspx controls dynamically, I noticed some
strange (at least to me) behavior.
Look at this code;

// FreeQuery : System.Web.UI.Page
// void cmdDo_Click(...)

GridView grid = new GridView();
grid.DataSource = source;
this.Controls.Add(grid); // HERE

The last line fails during execution!
But if I type like so;

//...
form1.Controls.Add(grid);

.... where form1 is generated in FreeQuery.aspx file;

....
<form id="form1" runat="server">
....

no failure will happen.

-------------------------
So what happens?
Why does this.Controls.Add fail?
What's the difference between this and form1?
....

Could you please share your knowledge with us.

Thanks in advance.

 

[Michael Nemtsev]

Hello Arman,

Because "this" has the type of "ASP._Default" and not of your form

AS> Hi,
AS>
AS> While writing code for creating aspx controls dynamically, I noticed
AS> some
AS> strange (at least to me) behavior.
AS> Look at this code;
AS> // FreeQuery : System.Web.UI.Page
AS> // void cmdDo_Click(...)
AS> GridView grid = new GridView();
AS> grid.DataSource = source;
AS> this.Controls.Add(grid); // HERE
AS> The last line fails during execution!
AS> But if I type like so;
AS> //...
AS> form1.Controls.Add(grid);
AS> ... where form1 is generated in FreeQuery.aspx file;
AS>
AS> ...
AS> <form id="form1" runat="server">
AS> ...
AS> no failure will happen.
AS>
AS> -------------------------
AS> So what happens?
AS> Why does this.Controls.Add fail?
AS> What's the difference between this and form1?
AS> ...
AS> Could you please share your knowledge with us.
AS>
AS> Thanks in advance.
AS>
---
WBR,
Michael Nemtsev :: blog: http://spaces.live.com/laflour

"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsche

 

[Michael Nemtsev]

Hello Michael ,

"ASP.<yourFormName_aspx>"

mistyped first time

MN> Hello Arman,
MN>
MN> Because "this" has the type of "ASP._Default" and not of your form
MN>
AS>> Hi,
AS>>
AS>> While writing code for creating aspx controls dynamically, I
AS>> noticed
AS>> some
AS>> strange (at least to me) behavior.
AS>> Look at this code;
AS>> // FreeQuery : System.Web.UI.Page
AS>> // void cmdDo_Click(...)
AS>> GridView grid = new GridView();
AS>> grid.DataSource = source;
AS>> this.Controls.Add(grid); // HERE
AS>> The last line fails during execution!
AS>> But if I type like so;
AS>> //...
AS>> form1.Controls.Add(grid);
AS>> ... where form1 is generated in FreeQuery.aspx file;
AS>> ...
AS>> <form id="form1" runat="server">
AS>> ...
AS>> no failure will happen.
AS>> -------------------------
AS>> So what happens?
AS>> Why does this.Controls.Add fail?
AS>> What's the difference between this and form1?
AS>> ...
AS>> Could you please share your knowledge with us.
AS>> Thanks in advance.
AS>>
MN> ---
MN> WBR,
MN> Michael Nemtsev :: blog: http://spaces.live.com/laflour
MN> "At times one remains faithful to a cause only because its opponents
MN> do not cease to be insipid." (c) Friedrich Nietzsche
MN>
---
WBR,
Michael Nemtsev :: blog: http://spaces.live.com/laflour

"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsch