I'm used to using VB.net for web programming.Often, I have something like:
Dim s as string = Session("s")
I get a string value for s from the web session. If there is no value in the web session, I get a blank string.However, AFAIK, in C#, I have to have something like the code below to do the same thing.
string s;
try { s = Session["s"].ToString(); }
catch { s = ""; }
I have alot of query strings on one of my seartch pages. The problem is that even if the corsponding setting is not set by the enduser it will be visible in the URL. Is there a way to avoid this?
In this case the Controller actions take an object of the following class :
[Code]....
Is it possible to avoid setting all the values in the URL when it is the default values that are used?
[URL]
how do you handle null data on gridview? and also the white spaces, it seems that the white spaces are converting to "Â "Â
 Note: i can't replace the  because i have 1 column thats in html form.Â
I have a dropdownlist on my view that is being populated from values in a database table and I've added a "--Select One--" header. Selecting a value from this list is optional (it maps to a nullable field in my table). Currently, if a user doesn't select a value from the ddl then it inserts an empty string into the field, wherease I'd prefer to keep it NULL.
View 5 RepliesVery often i write code like:
<img class="hasMenu" src="<%= (Model.Image==null)?Url.Content("~/Content/NoImage.jpg"):Model.Image.standard %>"
alt="Main image" />
Is there any predefined function which could beauty this code? Something like: ValueOrDefault(Model.Image.standard,Url.Content("~/Content/NoImage.jpg"))
On my development machine, the session state data is retained after a post back to the server. (XP VS 2008) (This is true if running from within VS or if running in browser with localhost.)On the deployed test server, the session state is blank in IE, but works in Firefox. (Svr 2003 IIS 6)Both machines are running the exact same code with the exact same imputs and same web.config. There is no code between the post backs that write to the session state.Newest addition to the server would be the consumption of a WCF web service. Could this be a symptom of something missing on the server(s) when trying to connect with WCF? I could not find any information other than installing the 3.0 framework. I have 3.5 SP1 installed on the test server.
View 2 Replieshave a form where I insert record via DetailView control. I have some string fields. For each string field (nvarchar in sql) I have defined the Default Value in the SQL SERVER (2008) as ''. Also I have added to each InsertParameter of the DetailsView a DefaultValue="".Yet still, if the user enters no value for one of the string fields, NULL is inserted into the table.
View 4 RepliesI need to pass some values around using session state. My approach is to first check if my session variable is null and if it is not, then proceed with my C# logic. Is that correct? Will my Session variable ever contain garbage in it, like a corrupted string? Or will I be guaranteed that it is null if not explicitly set.
if(Session["MyVariable"]!=null {
// Do some logic }
I have an ASP.NET web application that takes user input across several forms. Sort of like a wizard. On the first form, the user enters information then clicks the "Next" button. In the Click event of the button I save some information to the Session object (via Properties in the Master page). I then Redirect to the next page. Here is an example of what I am doing:
protected void NextButton_Click(Object sender, EventArgs args)
{
//Go to the next form
Master.SessionVal1 = Value1;
Master.SessionVal2 = Value2;
Response.Redirect("~/TheNextPage.aspx", false);
}
In the MasterPage.cs..
public long Value1
{
get { return (long)Session["Value1"]; }
set { Session["Value1"] = value; }
}
public long Value2
{
get { return (long)Session["Value2"]; }
set { Session["Value2"] = value; }
}
Pretty basic stuff. When I run this in debug mode in VS2008 it works perfectly. When I push this to a test server (IIS7) I get NullReference exceptions when I try to access Value1, Value2, etc. which is stored in the Session object. UPDATE: I have discovered that if I migrate the code to one server I get the problem as described above. BUT, if I promote to another server it works as expected. Both servers are Windows Server 2008 with IIS7. I have looked at the application pool settings and the state management settings and I do not see any differences.
In my application, session value automatically set into null.In certain workflow only it will set as null (Normally It's able to access value). Example, at the time of login, I will set session values. While, user deleting some entries from drop down list of specifc page,client script will show message like selected entry deleted. After that, flow point will move to master page. There I have to access session variables. It's getting null value. I tried to debug with Quick watch, at the pageload of master page only value set into null (automatically).
View 6 RepliesI have a clear button and a textbox in an aspx page. I set the session variable in this page as
String str = Textbox1.Text;
Session["TypeIds"] = str;
and I clear the sessions in a clear button event as
Session["TypeIds"]=null;.
Then when the user types some value in the textbox ,on Response.Redirect on another aspx page, the session variable returns null values.It does not retain its session state. The session state has to be maintained in the next page. Is it because this clear button event and setting explicitly to null creates this problem?
I have a field that is a DropDownList. When in the insert mode I want that field to be blank - It currently is displaying the first record in the table it pulls from. I was expecting to see an initial value setting in the DropDownList properties but do not. For example - suppose I have a field named locations that consist of 4 location (below). In "Insert" mode, location currently displays Dallas. I want it to be set to blank initially and the user select one. What am I mssing?
View 4 Replies[Code]....
This is having problems if the phone number is NULL or BLANK. Is there a way to fix it?
Is there a way to convert nulls in all the fields in a table into blanks using transact sql? For example strings will be "", numbers will be 0, and dates will be "1/1/1901".
I have over 500 columns, I don't want to go over each column and change the default value.
What is the proper way to check for null or empty strings on dynamic objects? This is the only solution I've found so far:
if (admin.PasswordHash.GetType() == typeof(DBNull) || admin.PasswordHash == string.Empty)
If the field is null, the object returned is DBNull.Value, but if the field is empty string, it's return as a System.String object. This makes it impossible to do regular "admin.PasswordHash == DBNull.Value" check, as that will fail whenever the field has been set to empty string. Is my example the right (and only) way to go?
I want to display a blank text box if the date in the table is null. Any ideas on this using MVC 2 RC? 1/1/0001 12:00:00 AM displaying for Null DateTime in Html.TextBoxFor(model => model.IssueDate)
View 11 RepliesI have house_info table in database and I have dropdownlist in my page that bind it from Shoppingcenter columns from house_info table...
in Shoppingcenter column in some rows are data and  some rows are NULL
now when I bind dropdown list it shows space in first Item after that it shows other Item that bind from house_info table I mean in dropdownlist shows NULL value (Space) that is in Shoppingcenter column
below is SP
ALTER procedure [dbo].[selectcentercityS]
@city nvarchar(30)
,@region nvarchar(5)
,@district nvarchar(30)
[Code] .....
I don't want it shows space in dropdownlist. What should I do?
below is House_info table in database
Id Behtop Service1 Service2
1 1111 Estate Null
2 2222 Home Home1
and I have 2 Textbox in page that users can enter text on them and update House_info tables column service1 and service2
below is SP:
@Service1 nvarchar(20)=NULL,
@Service2 nvarchar(20)=NULL
as
begin
update House_info set
Service1=@Service1,Service2=@Service2
END
and behind code
_cmd.Parameters.AddWithValue("@Service1", TxtMT1.Text);
_cmd.Parameters.AddWithValue("@Service2", TxtMT2.Text);
problem is that if users enter text in TB and click on button it update columns data but if they don't enter any thing in textbox it enter space in Table like:
Id Behtop Service1 Service2
1 1111 Estate
2 2222 Home Home1
I want if users don't enter any thing in text box it insert in table "NULL".How I can do it?
i have two text boxes and one button in web form. I need to display the contents of text boxes in a datatable in the same form, when i click on the button.
How can i do this using session array. I need to store values in session array. and get back the values from session when i need .
I have a problem with a SessionVariable. I will explain what is happening:
1. From the default.aspx I send Session["LoginByAdmin"] = "Dummy"; and then redirect to this page where I have the code below. So the Page_Load sees that this Session["LoginByAdmin"] != null and enter this page. This works fine !
2. In the Page_Load, I later fill a ListBox1 with foldernames.
3. With Button1_Click1, I will now delete the choosen Folder in the ListBox1 wich works fine the first time and the ListBox updates the new existing folders in the ListBox. (I have wrapped this inside an updatepanel)
The problems comes now when I try to delete a choosen folder in the ListBox1 the second time in a row. When I select a Folder in the ListBox1 and now Press Button1, I will be redirected to "Default.aspx". This meens that this code is running: (That meens that Session["LoginByAdmin"] == null and I have not set this to null anywhere. This is my big question how this variable can be = null here?
if (Session["LoginByAdmin"] == null)
Response.Redirect("Default.aspx");
break;
[Code]....
How should i insert null values into a database. I have textbox1 and the textbox2 will convert the value out of textbox1, when i the time i click save and the textbox1 is empty i got an error, "Conversion from string "" to type 'Date' is not valid." i just want to insert null value if the textbox is empty.
View 1 RepliesI created a new blank ASP.NET Website using VS 2008.
View 2 Replieswe have a AutoGenerateColumns-enabled WmxDataGrid in which we are able to update table rows in a DataBase connected with a SqlDataSource.
Each time we clear a field an empty string is written to the database where we want to write DBNull values.
At the moment we generate the update string via UPDATE... SET.. and the SQL Server function NULLIF(value, '').
Works proper but when I want to add the values to e.NewValues in BeginUpdate event I'm not able to read the values from the auto generated text boxes. How do I do that? Is there an easier way to automatically convert empty strings to NULL values?
I'm pretty new to C# and ASP.NET, so bear with me on this one. I'm setting up a page that receives query strings from the url. It then passes these strings to another method (in another class, actually), which goes on to do lots of things depending on the value of the query string.
The general structure looks something like this, where DoSomething() is actually part of another class that will be used by lots of different pages:
pretected void Page_Load (object sender, EventArgs e)
{
DoSomething (Request.QueryString["name"]);
}
public void DoSomething (string UrlVariable)
{
// if UrlVariable isn't set, initialize it to some value
// do stuff with UrlVariable
}
Here's what I'm wondering:
If the query string "name" isn't defined in the url, what does Request.QueryString return? an empty string? null? If it returns null, what happens if I try to pass null to a method that is expecting a string? Does the whole program fall apart, or can I check for null inside the DoSomething() method (after receiving the null string)?
The "name" is optional, so if the user doesn't set it, I'd like to detect that and initialize it to some default value. If possible, though, I'd like to put any validation inside DoSomething(), instead of doing the check on every page that requests the string.
I have been trying to do this all day but nothing seems to work. SOMEONE please enlighten me !!! I am adding products to a string and displaying them in another page. All is good .... up till here.
Now I have a problem when saving these strings (ie: the added products) into gridview. I tried using objectdatasource but I'm getting confused. Anyone done this before ? Basically when the products are in gridview I want the user to press 'purchase items' button, and the items are written to the database.