Dynamically Creating controls

[Guest]

Hello EveryBody,
I have a dropdownlist with some values as .net server controls & a button ,
on clicking a button i need to generate the choosen contorl dynamically.

I am giving a small glimpse of my code for your understanding
the aspx page has dropdwon list with values as below.

<aspropDownList id="DropDownList1" runat="server">
<asp:ListItem Value="Label">Label</asp:ListItem>
<asp:ListItem Value="DropDownList">DropDownList</asp:ListItem>
<asp:ListItem Value="DataGrid">DataGrid</asp:ListItem>
<asp:ListItem Value="DataList">DataList</asp:ListItem>
<asp:ListItem Value="CheckBox">CheckBox</asp:ListItem>
<asp:ListItem Value="RadioButton">RadioButton</asp:ListItem>
<asp:ListItem Value="RadioButton">RadioButton</asp:ListItem>
<asp:ListItem Value="Table">Table</asp:ListItem>
<asp:ListItem Value="TextBox">TextBox</asp:ListItem>
<asp:ListItem></asp:ListItem>
</aspropDownList>

now the code that gets executed at the click of the button is as follows

i am using the reflection name space

String strCtrlName = DropDownList1.SelectedItem.Value ;
Response.Write(strCtrlName);

Type tp=System.Type.GetType("System.Web.UI.WebControls."+strCtrlName ,true) ;
Object obj = Activator.CreateInstance(tp0;
PlaceHolder.Controls.Add(new obj );


but i get error at the line " Type
tp=System.Type.GetType("System.Web.UI.WebControls."+strCtrlName ,true) ; "

error below :

System.SystemException: {"Could not load type
System.Web.UI.WebControls.DataGrid from assembly TestingDynamicCtrl,
Version=1.0.1950.28617, Culture=neutral, PublicKeyToken=null."}
AssemblyName: "TestingDynamicCtrl, Version=1.0.1950.28617, Culture=neutral,
PublicKeyToken=null"
ClassName: "System.Web.UI.WebControls.DataGrid"
Message: "Could not load type System.Web.UI.WebControls.DataGrid from
assembly TestingDynamicCtrl, Version=1.0.1950.28617, Culture=neutral,
PublicKeyToken=null."
MessageArg: null
ResourceId: -2146233054
TypeName: "System.Web.UI.WebControls.DataGrid"

so could you pls help me out with your expert advices on solving the problem
and generating the control dynamically.

your expert advice would be highly appreciated.

Rgds
Shiju

 

[Karl Seguin]

When getting the type of a class, you need to specify the assembly, ala:

"System.Web.UI.WebControls.DropDownList, System.Web"

Since the "System.Web" assembly is in the GAC, you must also specify the
version, publickeytoken and culture, ala:

"System.Web.UI.WebControls.Label, System.Web, Version=1.0.5000.0,
Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

You can get the information by checking out c:\windows\assembly though
it'll be the same for you..

Karl

--
MY ASP.Net tutorials
http://www.openmymind.net/ - New and Improved (yes, the popup is
annoying)
http://www.openmymind.net/faq.aspx - unofficial newsgroup FAQ (more to
come!)

 

[Peter Laan]

Hello EveryBody,
I have a dropdownlist with some values as .net server controls & a button
,
on clicking a button i need to generate the choosen contorl dynamically.

I am giving a small glimpse of my code for your understanding
the aspx page has dropdwon list with values as below.

<aspropDownList id="DropDownList1" runat="server">
<asp:ListItem Value="Label">Label</asp:ListItem>
<asp:ListItem Value="DropDownList">DropDownList</asp:ListItem>
<asp:ListItem Value="DataGrid">DataGrid</asp:ListItem>
<asp:ListItem Value="DataList">DataList</asp:ListItem>
<asp:ListItem Value="CheckBox">CheckBox</asp:ListItem>
<asp:ListItem Value="RadioButton">RadioButton</asp:ListItem>
<asp:ListItem Value="RadioButton">RadioButton</asp:ListItem>
<asp:ListItem Value="Table">Table</asp:ListItem>
<asp:ListItem Value="TextBox">TextBox</asp:ListItem>
<asp:ListItem></asp:ListItem>
</aspropDownList>

now the code that gets executed at the click of the button is as follows

i am using the reflection name space

String strCtrlName = DropDownList1.SelectedItem.Value ;
Response.Write(strCtrlName);

Type tp=System.Type.GetType("System.Web.UI.WebControls."+strCtrlName
,true) ;
Object obj = Activator.CreateInstance(tp0;
PlaceHolder.Controls.Add(new obj );


but i get error at the line " Type
tp=System.Type.GetType("System.Web.UI.WebControls."+strCtrlName ,true) ;
"

Try adding the full assembly name to the string.
"System.Web.UI.WebControls.TextBox, System.Web, Version=1.0.5000.0,
Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

You can use

TextBox tb = new TextBox();

string tmp = tb.GetType().AssemblyQualifiedName;

to find out what it is.



Peter

 

[Guest]

Thanks Peter for the help

Try adding the full assembly name to the string.
"System.Web.UI.WebControls.TextBox, System.Web, Version=1.0.5000.0,
Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

You can use

TextBox tb = new TextBox();

string tmp = tb.GetType().AssemblyQualifiedName;

to find out what it is.



Peter

 

[Guest]

Thanks Karl for the speedy reply, it worked for me.

Rgds
Shiju