Add RadFilterTextFieldEditor programmatically

[dimrud]

Hello,
I am trying to add RadFilterTextFieldEditor programmatically. It works fine BUT after any action with the field I am getting an error

Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: Object reference not set to an instance of an object.

ASP code

   <telerik:RadAjaxPanel runat="server" ID="RadAjaxPanel1" LoadingPanelID="LoadingPanel1" EnableAJAX="true" >
             
                <telerik:RadFilter  runat="server" ID="RadFilter1" ExpressionPreviewPosition="Bottom" Enabled="false" RegisterWithScriptManager="true" EnableEmbeddedScripts="true"  EnableViewState ="true"  >
                </telerik:RadFilter>
            </telerik:RadAjaxPanel>

C# code
   RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
            editor.FieldName = "field1";
            editor.DataType = typeof(string);
            editor.DisplayName = "Field 1";
            RadFilter1.FieldEditors.Add(editor);
            RadFilterTextFieldEditor editor1 = new RadFilterTextFieldEditor();
            editor1.FieldName = "field2";
            editor1.DataType = typeof(string);
            editor1.DisplayName = "Field 2";
            RadFilter1.FieldEditors.Add(editor1);

Please help !!!

[Iana Tsolova]

Hello dimrud,

Is the C# code pasted placed in the Page_Load event handler? Try modifying it as below and see if it makes any difference:

RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
RadFilter1.FieldEditors.Add(editor1);
editor.FieldName = "field1";
editor.DataType = typeof(string);
editor.DisplayName = "Field 1";
RadFilter1.FieldEditors.Add(editor);
RadFilterTextFieldEditor editor1 = new RadFilterTextFieldEditor();
editor1.FieldName = "field2";
editor1.DataType = typeof(string);
editor1.DisplayName = "Field 2";

Sincerely yours,
Iana
the Telerik team

[dimrud]

Dear Lana,
You changed place of 1line
And now it works fine. Is it not strange behavior of the code ?
Anyway, Thank you very much.

My code :

RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
            editor.FieldName = "field1";
            editor.DataType = typeof(string);
            editor.DisplayName = "Field 1";
            RadFilter1.FieldEditors.Add(editor);
To :



RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
RadFilter1.FieldEditors.Add(editor1);

editor.FieldName = "field1";

editor.DataType = typeof(string);

editor.DisplayName = "Field 1";

[Bruce]

It does not make sense to me. The new code should give a compiling error because editor1 is not defined yet when it is added to the editor collection.

Can someone explain this?

Thanks

[Iana Tsolova]

Hello Bruce,

Please excuse me for the misleading code. Here is the proper one:

RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
RadFilter1.FieldEditors.Add(editor);
editor.FieldName = "field1";
editor.DataType = typeof(string);
editor.DisplayName = "Field 1";

RadFilterTextFieldEditor editor1 = new RadFilterTextFieldEditor();
RadFilter1.FieldEditors.Add(editor1);
editor1.FieldName = "field2";
editor1.DataType = typeof(string);
editor1.DisplayName = "Field 2";

Note that this code is to be used when adding the editors on Page_Load.
In case you are adding them on Page_Init, here is the code one should use:

RadFilterTextFieldEditor editor = new RadFilterTextFieldEditor();
editor.FieldName = "field1";
editor.DataType = typeof(string);
editor.DisplayName = "Field 1";
RadFilter1.FieldEditors.Add(editor);

RadFilterTextFieldEditor editor1 = new RadFilterTextFieldEditor();
editor1.FieldName = "field2";
editor1.DataType = typeof(string);
editor1.DisplayName = "Field 2";
RadFilter1.FieldEditors.Add(editor1);

Note that on Page_Init, the editor properties are first set, and then it is added to the FieldEditors collection. And it is opposite when editors are created on Page_Load: the editor is first added to the FieldEditors collection and then its properties are set. Also on Page_Load editors are added only on initial load (in if(!IsPostBack) statement) whereas on Page_Init are added on each postback.

I hope this makes it all clear.

All the best,
Iana
the Telerik team