C# - Inherited Class Giving Null Exceptions?
Mar 1, 2010Here is my simple class, where i inherit from UserControl.
public class Test:System.Web.UI.UserControl
{
public void BindGrid()
[code]...
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I then setup an Entity Data Model that pulled in both of these tables and created classes BaseProduct and Shirt. So, in my model, I want to do something like this:
[Code]....
The main problem I have with this, is that if I do any kind of condition on CatalogNum or ListPrice, then my performance goes to crap. One of the main things we will want to do is something like this:
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This takes an enormous performance hit, and I suspect it is because the partial class above returns to the database for each shirt.
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Mar 24, 2010Well..the title sort of explains the problem..
I have a class that inherits the HyperLink-class, but I want to "hide" the CssClass-property from the intellisense and also from the "designer-view"..
I have tried the following:
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Web Forms :: Master Page Controls Cause Null Reference Exceptions?
Mar 10, 2010I've got a master page where I've created two content place holders ('menu content place holder' and 'main body content place holder'). I've placed several controls (drop down lists and a calendar) in one of these content place holders (the 'menu content place holder'). In my content page I've set the 'menu content place holder' to 'Default to Master page content'. In my 'main body content place holder' I've included several controls (table, labels) which depend on the user selected items in the 'menu content place holder'.
After including a reference in all the necessary places- like this:
DropDownList ddlList1 = Master.FindControl("ddlList1")
as
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I still get the following exception (this exception occurs in my content page):
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details:System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
[Code]....
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<a onclick="openwindow();" ahref="#">
<img src="Images/calendar.gif" style="width: 20px; height: 20px" border=0/></a>
<input ID="Text1" runat="server" readonly="readOnly" type="text" />
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window.open('/Calender.aspx', 'calendar_window','width=154,height=188');
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code on opened window from content page
protected void Calender1_SelectionChanged(object sender, EventArgs e)
{
string strjscript = "<script language='javascript'>";
strjscript += "window.opener." + HttpContext.Current.Request.QueryString["formname"];
strjscript += ".value = '" + Calender1.SelectedDate.ToString("yyyy-MM-dd") + "'; window.close();";
strjscript += "</script" + ">";
Literal1.Text = strjscript;
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Web Forms :: Onclick Event Giving Null Reference Exception?
Dec 15, 2010let me see if I can explain this clearly. I have a gridview control
and I am trying to use the Edit function. In my gridview, there are numerous rows. I pick one to change and click Edit. I then see the boss name in my gridview and click "Change". When I click Change, I'm expecting two fields to appear, one is a label, the other is a DropDownList. I get this error when I click:
System.NullReferenceException was unhandled by user code
Message=Object reference not set to an instance of an object.
Source=App_Web_lzmklgbg
StackTrace:
at Training_TRManageOrg.LinkButton1_Click(Object sender, EventArgs e) in d:projectsediting.aspx.cs:line 108
at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e)
at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
InnerException:
Gridview HTML:
<asp:TemplateField HeaderText="Director">
<EditItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("director") %>'></asp:Label>
<asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click">Change</asp:LinkButton>
<asp:Label ID="Label4" runat="server" Text="Director" Visible="False"></asp:Label>
-
<asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="trDirector"
DataTextField="name" DataValueField="id" onselectedindexchanged="DropDownList2_SelectedIndexChanged"
Visible="False"></asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("director") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
Code Behind:
protected void LinkButton1_Click(object sender, EventArgs e)
{
DropDownList DropDownList1 = ((DropDownList)FindControl("DropDownList1"));
DropDownList1.Visible = true; // this line is where the exception occurs
Label3.Visible = true;
}
I figure I must be overlooking something so I'm asking what am I missing?
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[Code]....
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I am posting my code for your reference -
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My gridview code is -
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<%@ Control Language="C#" AutoEventWireup="true" Inherits="Namespace.Path.To.ClassName" %>
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namespace Namespace.Path.To
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//class Category
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using(dr)
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In my SAP.NEt project, defined a constant:
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[Code]....
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[code]...
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