Data Controls :: Check If Data Exist In List Generic Collection Using C#

Apr 19, 2014

i want to check my collection so i can add a new customer as long as the username does not exist in the collection i do not want 2 customers to be able to have the same username.

i have been trying many different things to try to get this to work but i am not exactly sure what i should be doing I have a aspforum and collection C# class of the list.

here is some things that i have tried

CustomerExists()      i also have a collection of List<Customers>
 //HERE IS MY EXISTS METHOD
public static Boolean IfCustomerExists(string login) {
List<Customer> theGuy = Collections.Customers;
bool exist = false;
foreach (Customer customer in theGuy)

[Code]....

View 1 Replies


Similar Messages:

Iterating System.Collection.Generic.List.Add Does Not Work As Expected?

Mar 7, 2010

I was building an application for a project with .NET 3.5 and I noticed a weird behaviour of the List.Add method:

I have built my own class to organize data pulled from a database, and I use a while cycle to iterate through it.

However, when I List.Add(item), the whole content of the list is substituted with the last content pulled.

An example:

Suppose you have 3 users in a DB, each one identified with an ID and a username:

| ID | username |
| 1 | John |
| 2 | Fred |
| 3 | Paul |

and you have a "Users" class defined as

public class Users
{
private Int32 iD;
private String username;
public Int32 ID
{
get { return iD; }
set { iD = value; }
}
public String Username
{
get { return username; }
set { username = value; }
}
}

So you write this function:

[... SQL definitions - sdr is a SqlDataReader ...]
List<Users> userlist = new List<Users>();
if (sdr.HasRows) //There are users
{
Users user = new Users();
while (sdr.Read())
{
user.ID = sdr.GetInt32(0);
user.username = sdr.GetString(1);
userlist.Add(user);
}
}

What you expect (I expect) is userlist containing:

| ID | username |
| 1 | John |
| 2 | Fred |
| 3 | Paul |

What I actually get is, instead

| ID | username |
| 3 | Paul |
| 3 | Paul |
| 3 | Paul |

View 3 Replies

Forms Data Controls :: Check Already Exist Data From Database Without Post Back?

Apr 19, 2010

I have developed an asp.net application ... I have a textbox where user will enter is name ... I need to check if the name is already exist in the database table column when ever user enter their name with out post back . If user exist mean it should show a msg user already exist .....

View 6 Replies

Forms Data Controls :: Check If Data Exist In Database BEFORE Insert New Item

Dec 3, 2010

I have a GridView on a page for maintainance of the database (mdf). Under this GridView1 I have a FormView1 where I use the ItemInsertTemplate to Insert new rows in my database (which shows the data in GridView1). The first textbox (BIDTextBox) i have on this template, contains text which identify a person. I would like to have a routine which checks if the same value that is entered in the BIDTextBox allready exists in the database. This routine should be fired upon leaving the control BIDTextBox.

I have tried with some stored procedure in my database, but that dosn't seem to do the trick. The most logical to me seems to do a loop thru my table "Ansatte" in my database using sql, selecting any occurence from the field "BID" in my table "Ansatte" that is simillar to the text entered in the BIDTextBox.

View 6 Replies

State Management :: Cache System.Collection.Generic.List Object?

Aug 22, 2010

I need to cache System.Collection.Generic.List object with expiration time

var Root = from feed in feedhotel.Descendants(ota + "HotelContent")
where (feed.Attribute("HotelCode") != null)
select new xmlhotel()
{
};
return Root.ToList();

Is it possible to cache Root.ToList() for some time....

View 1 Replies

Data Controls :: How To Check And Update Exist Data In SQL

Jan 3, 2014

As following code condition statement show that  transfer data from Location A to Location B. May i know how if to update the exist data in Location B ?.Example,from  Location A Qty is 10 , transfer Qty to  Location B is 5, then Location A is 5. So,How if transfer  again from location A qty 2 to Location B. then update the location b qty.

USE [CIMProRPT01]
GO
/****** Object: StoredProcedure [dbo].[MMSLocTrans_InsertOrUpdate] Script Date: 01/03/2014 13:46:14 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

[code]....

View 1 Replies

Web Forms :: Export A Generic List Collection To Excel File With Applying Styles

Oct 22, 2012

I need a list to export in excel and i need the following to achieve in the exported excell

-  I need the header of the excel with font bold and size should be 14px of font.

-  Other Cell try should be 12px of the font

- Right align the particular column in the excel

View 1 Replies

Forms Data Controls :: Pull Data Coming From Generic List In OnRowDataBound?

Feb 15, 2010

I need to "massage" the data a little during OnRowDataBound. When I used DataTable as my data source for my GridView, I could do the following:

[Code]....

How do I grab the row data if I'm getting it from List<Product>?

View 3 Replies

Forms Data Controls :: How To Read ListView Data Into Generic List

Aug 19, 2010

I have a ListView which is filled by generic list of type MyClass. I can easily bind data from this list into ListView. But I have problems with reading data in opposite direction. This is my class:

[Code]....

I have also generic list of type MyClass:

[Code]....

Finally I bind data to ListView this way:

[Code]....

My ListView template:

[Code]....

How can I read data from ListView into my List list?

The operation of reading ListView data into List generic list should begin after clicking the button "GetData".

I saw the following advice:

[Code]....

but it does not work - the DataItem property of each Item of ListView has null value. The point is that I have generic list with data. I am binding this data into ListView which can be edited by user. After that after click Save or GetData data from ListView is read into generic list of MyClass type.

View 8 Replies

Forms Data Controls :: Check If A User Already Exist In A Gridview?

Feb 5, 2010

I have detailed view and a grid view, the DetailedView does the inserting into the Grid view. On my table( Ussing SQL Server), i have a username and year and allocation. What do i do so that when an allocation is given to a user for a year that already exit, it refuses.

View 9 Replies

Forms Data Controls :: Check The Value Is Already Exist In The Grid View?

Mar 17, 2010

I am not using any database for data source.I can enter the some value in text box and the entered value is automatically added in the gridview.How can i validate not adding same item numbers in gridview.And i also calculated grand total for amount column.If i remove any records means how to recalculate current total.Any one can tell solution for this issue.I am waiting for reply ASAP.

View 2 Replies

Data Controls :: How To Check Username Exist In Database Without Postback

May 7, 2015

How to check username is exist in database or not without postback the page...

View 1 Replies

Web Forms :: Check Value Can Exist In Dropdown List

Feb 10, 2010

System.ArgumentOutOfRangeException: 'DropDownList' has a SelectedValue which is invalid because it does not exist in the list of items.this question has been for a long time ago but seem no actual answer for it except for catching the exception.I don't want just catch error instead of check first whether the value exist in drop down list. My scenario was different from the other. my data source is bind to a datatable, all is in hard code.

View 14 Replies

Forms Data Controls :: Generic List To DataTable

Sep 20, 2010

Generic List to DataTable

View 1 Replies

Forms Data Controls :: Binding A Generic List To A Gridview?

Aug 9, 2010

Split off from [URL]

Getting records From DataBase using DataTale which contain 1000 Rows, then binding to GridView using Generic List. Like above Example

GridView1.DataSource= GetData();
GridView1.Binding();

Now i want to do search, sorting & Paging in the GridView with out Postback of the Page & with out hitting the DataBase when do Paging or searching in GridView.

View 3 Replies

Data Controls :: Bind Generic List Of DataRow To GridView

May 8, 2013

How to bind generic list of DataRow to gridView...

I am using MVC arch , in classDAO m fetching data from table and in bussiness layer ,storing datatable into list<DataRow> and finally in controller , i want to bind in gridview..how can i read each datarow value and bind to gridview..

View 1 Replies

Data Controls :: Populate Generic List From GridView With TextBox

Apr 15, 2014

I am displaying data with in textboxes in gridview here user will change the values my problam is how to get the gridview data and assign it to List?

View 1 Replies

Data Controls :: DropDownList Has A SelectedValue Which Is Invalid Because It Does Not Exist In The List

Jun 9, 2013

Before this, everything is fine when running the project After I've put "SelectedValue" below to the field,

<asp:TemplateField HeaderText="Interest">
<ItemTemplate>
<asp:DropDownList ID="ddl" OnSelectedIndexChanged="ddl_IndexChanged" SelectedValue='<%# bind("int_id") %>' AutoPostBack="true" runat="server">
</asp:DropDownList>
</ItemTemplate>

[CODE]

View 1 Replies

Forms Data Controls :: Sorting Gridview Filled From Generic List?

Jun 9, 2010

I have a problem i just cant get around...I'm trying to sort the contents of a gridview that gets filled from a List<T>.

(working in DAL, BLL & Presentation layers).

The Gridview's source code:

[code]....

What i cant figure out is how to implement the sort method to the gridview when fetching data from a generic list... I have been Googling my a** of trying to solve this.

View 4 Replies

Forms Data Controls :: Format Generic List Bound To Gridview

Aug 21, 2010

I have a generic list of a custom type. The custom type has a string and double.I'm binding the list to a gridview and it outputs everything fine.I'm trying to format the double column into a currency format. It is in a template field as I'm calculating a running total. I pass the value to a function that returns a double and adds the current value to a running total which I will show in the footer.

The format is not changing to currency as expected when using String.Format("{0:c}", GetTotal(Convert.ToDouble(Eval("Amount"))))

View 1 Replies

Forms Data Controls :: Delete And Update Implementations For A Generic List?

Nov 30, 2010

I have a following generic list method that contains some data for a gridview. I need to supply edit and delete functionality for it.


List<students> List(string id)
{
List<students> st = new List<students>();

[code]...

View 4 Replies

Data Controls :: Pass Generic List As A Message From Server To Client

Sep 9, 2013

im just testing out signalr and i am having too much fun and got a little bit far from my usual skill now my question is can i pass a list to the client here is my code actually i learned this from you mr aspsinnipets

Public Sub Send(message As String, id As String)
Dim tomessage = OnlineUser.userObj.Where(Function(users) users.userId = id).[Select](Function(users) users.connectionId).SingleOrDefault()
Dim customers As New List(Of locationslist)
customers.Add(New locationslist)
customers((customers.Count - 1)).CITE_NR = message

[code]....

View 1 Replies

Forms Data Controls :: 'DropDownList1' Has A SelectedValue Which Is Invalid Because It Does Not Exist In The List Of It?

Jan 24, 2011

We use gridview for showing a data from table.It show fine in certain case like in table field dispostion is data and test but in table we put the string Ineligible Member/Member No Longer Enrolled - Spoke to Target and Wrong Number After Skip Tracing then it gives error. 'DropDownList1' has a SelectedValue which is invalid because it does not exist in the list of items.

The following is snippest my code ,tell me where i am wrong.

[Code]....

View 5 Replies

Forms Data Controls :: 'DropDownList6' Has A SelectedValue Which Is Invalid Because It Does Not Exist In The List Of It?

Oct 5, 2010

In my asp.net page I have a formview. In the formview's InsertItemTemplate I declare a dropdown list as below:

<td>
<asp:DropDownList ID="DropDownList6" runat="server" text='<%# Bind("District") %>'
DataSourceID="SqlDataSource6" DataTextField="District"
DataValueField="District">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource6" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [District] FROM [tblDistricts]"></asp:SqlDataSource>
</td>
and this works perfectly fine.
In the EditItemtemplate I declare a similar dropdownlist as below to edit district values:
<td>
<asp:DropDownList ID="DropDownList6" runat="server" selectedvalue='<%# Bind("District") %>'
DataSourceID="SqlDataSource6" DataTextField="District"
DataValueField="District">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource6" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [District] FROM [tblDistricts]"></asp:SqlDataSource>
</td>

But whenever I try to edit the data I get the error:

'DropDownList6' has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value And the values I am trying to edit were entered into the table by the dropdownlist declared in the insertitemtemplate dropdownlist6 listed above. And no values were deleted from the table.

View 4 Replies

Data Controls :: DStation Has SelectedValue Which Is Invalid Because It Does Not Exist In List Of Items

Dec 17, 2013

How to solver this error? I am getting error for "DropDown"

Error: 'DStation' has a SelectedValue which is invalid because it does not exist in the list of items.Parameter name: value on line: DStation.DataBind();

My .cs code is below

string CommandText = ("select distinct StationName from stations where DeletionDate is null");
DStation.DataSource = DataManager.DatabaseManager.GetOrCreateConnection
(DataManager.DatabaseManager.ConnectionType.MySQL).GetData(CommandText);
DStation.DataTextField = "StationName";

[Code] .....

View 1 Replies







Copyrights 2005-15 www.BigResource.com, All rights reserved