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In a custom web control I took a look at some time ago, I saw that the writer programmer locked the thread before editing or reading from one of the member variables of the control (a generic Dictionary). Now, what I guess the locking does, because of the result of the script, is making that member variable a kind of application variable. My question is, how is it that the locking before touching the variable makes it a sort of application variable (available to all users viewing the page)?
Thanks in advance
-- modified at 8:30 Tuesday 31st July, 2007
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Hi,
I am new to asp.net but have learnt a lot through the tutorials and random searching here and elsewhere. Have many years expereince with classic ASP but this task I am working on is sending me around the bend !
I want to have a nested repeater (this bit I understand fine) but am unsure how to make my data from two tables in the one database join together.
I have a table called boatcats which list a few different categoies of boat and I have a second table called 'boats' that list all of the boats and their details. The two tables share boatcats.ID and boats.catid
I doubt my code is heading in the right direction and I am unsure how to link the two queries. I am using VB not C# and should I be doing this sort of thing at code level (which I am used to in asp classic or with Visual Web Developer 2005)
Code so far is....
<script language="vb" runat="server">
Sub Page_Load(sender as Object, e as EventArgs)
If Not Page.IsPostBack then
BindData() 'Only bind the data on the first page load
End If
End Sub
Sub BindData()
dim dbconn,strq,dbcomm,dbread
dbconn=New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;data source=" & server.mappath("boats.mdb"))
dbconn.Open()
strq = "Select * from boatcats"
dbcomm=New OleDbCommand(strq,dbconn)
dbread=dbcomm.ExecuteReader()
boatcats.DataSource=dbread
boatcats.DataBind()
dbread.Close()
dbconn.Close()
End Sub
Sub BindData2()
dim dbconn2,strq2,dbcomm2,dbread2,boats2
dbconn2=New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;data source=" & server.mappath("boats.mdb"))
dbconn2.Open()
strq2 = "Select * from boats"
dbcomm2=New OleDbCommand(strq2,dbconn2)
dbread2=dbcomm2.ExecuteReader()
boats.DataSource=dbread2
boats.DataBind()
dbread2.Close()
dbconn2.Close()
end sub
</script>
I havn't added the asp:repeater section, this I have no problems with.
Any help appreciated.
Martin
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Depends on what you want to do with the boatcats data i guess, but i will assume this is what you want in the repeater:
Boat Category
Boat Name
Boat Name
Boat Category
Boat Name
...
then you wouldn't need to have a nested repeater, you could do it in one repeater and just do a join in you database query:
"Select * from boats join boatcats on boatcats.id on boats.boatcats.id order by boatcats.name, boats.name"
(returning all fields from boats and boatcats) and order on the category name then the boat name.
OR
"Select boats.*, boatcats.title [boatCategoryTitle] from boats join boatcats on boatcats.id on boats.boatcats.id order by boatcats.name, boats.name"
(returning all fields from boats and boatcat title) and order on the category name then the boat name.
That way you can just put in two placeholders within the <ItemTemplate> and on the placeholder have visible="<%# ShowCategory(Container.DataItem) %>" (for the header placeholder) then visible="<%# !ShowCategory(Container.DataItem) %>" (for the boat section placeholder).
Then put a function ShowCategory(object dataItem) which works out whether this is the same category as the last, if not store the category name and show the header. Have another function inside that displays the name of the category. Then display whatever you want in the body section....
Does that make sense?? Is that what you are trying to do??
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Thanks Daniel for the reply. I did think of the join in the query but brushed past it as I was keen to see what .net had to offer. Ultimately the page is to be searched on, and all boats regardless of matching the criteria are to be displayed. Those that match the criteria are to have an image in colour of the boat and the non search matching boats to be greyed out (A black and white pic of the same boat)
I did the whole exercise in under 2 hours in classic asp but am getting no where fast in .net !
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You could probably use a nested repeater if you wanted to bring the data back in a dataset and provided information about the relationship between the two tables, but if you just need to display like above then this would be the better option.
Good luck.
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hi all i have a small but complex problem i need to select the row of a data grid using the check box cheched event or radio button checked event.and display the selected row elements in respective textboxes.
in short i need to use select command funcionality using chkbox checked event
please letme know possible solutions by d by i'm working on ASP.NET 2005 + SQL SERVER 2005
entry level s/w professional
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A.Vishal wrote: i need to select the row of a data grid using the check box cheched event or radio button checked event.and display the selected row elements in respective textboxes.
Where is your respective textboxes ? Is it inside grid ? Do you want to implement this using javascript ?
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the text boxes are out side the grid and i need to retrieve all the selected row information on clicking the link button (its data bound)item template of grid .
i was unable to fetch the text field of the link button under link button clicked event, if i can fetch the text of clicked link button i would be able to get all other credentials using new datasource.
i guess u got it pls let me know if any possible solns
entry level s/w professional
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Hi, I have a question, I very often get exceptions like: Object reference not set to an instance of an object.
Why does it occur?
for exmaple in this code:
SDSCheckUser.SelectCommand = "SELECT [newuser] FROM [Users] WHERE [username] = "+username;<br />
DataView view1 = (DataView)SDSCheckUser.Select(DataSourceSelectArguments.Empty);<br />
bool newuser = (bool)view1.Table.Rows[0].ItemArray[0];
Thanx
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It means one of your casted objects returned null. You keep getting it because the code is poor - it should always check return values.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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could be because if there is no user that matches the username there won't be any data at Table.Rows[0].ItemArray[0]....well that seems the most likely anyways.
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Server Error in '/' Application.
--------------------------------------------------------------------------------
Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: Cannot create/shadow copy 'Utilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' when that file already exists.
Source Error:
Line 121: <roleManager defaultProvider="DefaultRoleProvider" enabled="true">
Line 122: <providers>
Line 123: <add name="DefaultRoleProvider" type="EnPointe.SOOnWeb.Utilities.Security.SOWRoleProvider" />
Line 124: </providers>
Line 125: </roleManager>
Source File: C:\Projects\SalesIntranet\WebInterface\web.config Line: 123
Assembly Load Trace: The following information can be helpful to determine why the assembly 'Utilities' could not be loaded.
=== Pre-bind state information ===
LOG: User = PK-NAVAIDA\ASPNET
LOG: DisplayName = Utilities
(Partial)
LOG: Appbase = file:///C:/Projects/SalesIntranet/WebInterface/
LOG: Initial PrivatePath = C:\Projects\SalesIntranet\WebInterface\bin
Calling assembly : (Unknown).
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\Projects\SalesIntranet\WebInterface\web.config
LOG: Using host configuration file: C:\WINNT\Microsoft.NET\Framework\v2.0.50727\aspnet.config
LOG: Using machine configuration file from C:\WINNT\Microsoft.NET\Framework\v2.0.50727\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v2.0.50727/Temporary ASP.NET Files/root/9a43166b/396af647/Utilities.DLL.
LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v2.0.50727/Temporary ASP.NET Files/root/9a43166b/396af647/Utilities/Utilities.DLL.
LOG: Attempting download of new URL file:///C:/Projects/SalesIntranet/WebInterface/bin/Utilities.DLL.
LOG: Using application configuration file: C:\Projects\SalesIntranet\WebInterface\web.config
LOG: Using host configuration file: C:\WINNT\Microsoft.NET\Framework\v2.0.50727\aspnet.config
LOG: Using machine configuration file from C:\WINNT\Microsoft.NET\Framework\v2.0.50727\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
ERR: Failed to complete setup of assembly (hr = 0x800700b7). Probing terminated.
--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50727.832; ASP.NET Version:2.0.50727
WHAT IS THIS STUPID ERROR, PLEASE HELP ME TO GET RID OF THIS PROBLEM> 
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Don't double post.
The file is in use. Reboot.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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hi,
thanks for your reply but sorry to say that this is not solution to my problem. also i have critical problem for that issue, kindly if you have any solution to my problem, i shall be greatful to you all.
Neo
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Hi, I've read that usually if one wants to display binary data from a data store one has to read it using the ExecuteScalar() method of the SqlCommand class. Then caste the object the method returns by putting it in a byte array and display it like the following.
Response.ContentType = "application/pdf"<br />
<br />
Response.BinaryWrite(buffer);
How do I set the Mime Type of the file retrieved from the database dynamically? What I have in mind is this, suppose I have 3 fields in my database table with their data stored like the following:
ResumeID Int Resumes Blob ResumeTypes Varchar(50)
1 Something "application/doc"
2 Another Something "image/img"
I then get the value of the ResumeTypes field of my database and place it in the code like this
Response.ContentType = "Value of ResumeTypes"
How do I go about doing that? Thank you in advance for your help.
-- modified at 21:28 Monday 30th July, 2007
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You'd do it exactly like this, store the mime type and pull it out of the DB.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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Hi Christian, the problem is I'm unsure about how to retrieve the info from the database. I have already written code to connect to a database and retrieve data but its for a different purpose. The following is the modified code to try to make the program dynamically set the mime type.
For i = 0 To ListBox1.Items.Count - 1
If ListBox1.Items(i).Selected Then
DBCommand = New OdbcCommand("SELECT DocID, Document, DocTypes From ArchiveTB where Authors = '" & ListBox1.Items(i).Text & "'", DBConn)
End If
Next
If Not IsNothing(DBConn) Then
DBConn.Open()
DBCommand.Connection = DBConn
Dim DS As New DataSet
Dim AD As New OdbcDataAdapter(DBCommand)
AD.Fill(DS, "ArchiveTB")
AD.Dispose()
Me.ListBox2.DataSource = DS
Me.ListBox2.DataTextField = "DocType"
Me.ListBox2.DataValueField = "DocID"
ListBox2.DataBind()
Dim buffer As Byte() = New Byte(contentLength - 1) {}
reader.GetBytes(0, 0, buffer, 0, contentLength)
Response.ContentType = "" & ListBox2.SelectedItem.Text & ""
Response.BinaryWrite(buffer)
End If
Please take a look and see if I can do it this way. However, I don't want to force the user to choose the the mime type, how can I do this without using a list box? Thanks again for your help.
-- modified at 3:20 Tuesday 31st July, 2007
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To reiterate advice I've given you many times before
1 - use real variable names, not listbox1
2 - don't grab text from a control to create SQL, it can be used for injection attacks
3 - don't iterate over a collection looking for the item that is selected, when the listbox has a selecteditem property
I despair that we are discussing the same function, week after week, but you don't actually take the advice given to you.
ASPnoob wrote: Response.ContentType = "" & CurrentModels.SelectedItem.Text & ""
Why are you grabbing the mime type from the CurrentModels control, and where does the buffer variable come from ? What does this have to do wtih ListBox2, anything ?
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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I am facing one typical problem, that is I have to just create update panels dynamically have server side controls in their content template, which is done through clicking the button which is in another
update panel whose update mode is set to conditional, this is bcoz when the user click to add controls and fill them with values and then again click to generate more controls , the previously generated controls loses its values, so i put the button that generate controls dynamically in another update panel and set its update mode to conditional, now when i click on to add controls nothin happens , but when i took button to outside panel it adds but page postback , i want to add controls using partial postback and when i click add button it will not cause the previously dynamically generated controls to lost their values.
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Hello All
I have a custom web control i am finishing, and have run into an issue that has caused problems for me in the past.
That problem being that when said button is clicked, the page state (ViewState) is only changed after the second click.
These are programmatically created buttons.
This appears to be some weird postback issue, but I am about out of ideas here.
Last time I ran into this, I simply forced a full-page reload, and that was enough. As this is part of a control, that hack is not an option.
Can someone please enlighten me as to how a control as "simple" as a button can "just" do what it is supposed to on the FIRST click?
--stoland
-- modified at 17:28 Monday 30th July, 2007
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Usually this means that your code is setting the viewstate at the wrong point in the page lifecycle. The order is page_load, events, page_prerender. Set some breakpoints and walk through your code to see the sequence of events, and you'll work out where your bug is. The button, I guarentee you, is working fine.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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I was wondering if its possible to set the visibility element of an HTML table, using the aspx.vb file. I know you cant set the ID and call it like that. Just wondering if there is any good way to do this (preferably without JS). What i'm doing is setting certain tables to be visible based on who logs in.
Thanks,
Nate Lindley
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yes, it is easy to achieve but what you have to do is to built the table (add rows and colums) dynamically at runtime in the table...
e.g in code-behind file (default.vb) use
if condition=true then
//add code to create table with 3 rows and 5 colums
elseif condition2 =true then
// add code to create table with 2 rows and 2 colums
elseif condition3 = true then
and so on......hope it helps
Note: at Design time you should just place the Table control on the place where it needs to drawn at runtime... then handle, height, width, and etc attributes programtically in code behind file
:- Rashid Ali -:
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Hey Rashad,
Yea I could do that to create a data table, but I just want an HTML table. Basically the situation is that I'm going to have a page with 5 tables on it (one on top of the other). Each table has multiple rows (one for each PDF for that state), and I want to set the Visibility attribute (style) of each one.
Thanks,
Nate
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i think u can achieve the same task using Server Table Control, why you want to use html table only?
:- Rashid Ali -:
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