I posted a question earlier about a using a list to store data then pass it through a session variable I have this code so far:
Default page:
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
var basketItems = new List<int>();
basketItems.Add(1);//I need to get the ID of the book I am selecting from the gridView
Session["BasketList"] = basketItems;
Response.Redirect("Basket.aspx");
}
Basket Page:
protected void Page_Init(object sender, EventArgs e)
{
var basketListItems = (List<int>)Session["BasketList"];
}
Then I have a gridView control on the basket page using this syntax:
SelectCommand="SELECT * FROM [tblBook] WHERE ([BookID] = ?)">
I thought this would match the bookID from the database to whatever the ID from the bookID in the gridView is, then output the books.
Basically I need to be able to click select on the gridview and then take the id of the book that has been clicked and then send it to the basket page where the book info can be displayed from the book table.
Use generic version of List instead List<int>
Related
I can successfully select the data I want to update to another page and populate my text boxes but if I set the selected values to my textbox and then try to update it wouldn't work and the same data is shown in database table.
However if I DO NOT set those values to my textboxes, then I can successfully update which is not what I am after.
I would like the user to see the data and record that s being updated
Here is my code:
protected void Page_Load(object sender, EventArgs e)
{
UserClassesDataContext db= new UserClassesDataContext();
var qr = from user in db.Users
where user.user_id == new Guid(Request.QueryString["user_id"])
select user;
foreach (var q in qr)
{
TextBox1.Text = q.user_name;
TextBox2.Text = q.password;
}
}
protected void Button1_Click(object sender, EventArgs e)
{
UserClassesDataContext db = new UserClassesDataContext();
var qr = from user in db.Users
where user.user_id == new Guid(Request.QueryString["user_id"])
select user;
foreach (var q in qr)
{
q.user_name = TextBox1.Text;
q.password = TextBox2.Text;
}
db.SubmitChanges();
Response.Redirect("Default.aspx");
}
What am I doing wrong?
Thanks
The problem is, when you submit the button, the code inside Page_Load event is executing again.That means it is reading the data from your table and setting the value to textboxes(thus overwriting what user updated via the form ) and you are updating your record with this values (original values). So basically you are updating the rows with same values.
You can use the Page.IsPostBack property to determine whether the event is occurred by a postback(button click) or initial page load.
This should fix it.
protected void Page_Load(object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
// to do: read and set to textbox here.
}
}
I have users table and i want the manageer will be able to select from a user he wants to change/delete. How can I embed into the html code this sql query. Needless to say that in the .cs i need to start with
public string user = "";
protected void Page_Load(object sender, EventArgs e)
{
string sql;
sql="SELECT 'usrname' FROM 'Users'";
user = MyAdoHelper.printDataTable("Database.mdf", sqlq);
}
but how can i convert user to a list?
thanks.
i have a calender and i was able to add text-box inside the cell using the day-render event but what i am trying to do is allow the user to add data to the text-box and then press add and the content is added to a database and showed inside that same text-box:
here is what i did:
protected void Page_Load(object sender, EventArgs e)
{
Calendar1.SelectedDate = DateTime.Now;
}
protected void update(object sender, DayRenderEventArgs e)
{
TextBox tb = new TextBox();
Button1.click += new EventHandler(insert);
e.Cell.Controls.Add(Button1);
e.Cell.Controls.Add(textBox2);
}
protected void insert(object sender, EventArgs e)
{
}
and i know how to insert the data but i am lost on how to identify it and output it back to the same text box
thanks
Well I'm not sure exactly what part you are lost on based on your question, so short of providing a complete working example I'll hit some of the main points:
1) To identify the data you are inserting, attach a date (and time if applicable) to the record. (Edit: are you looking for a mechanism to accomplish this? If so post your current DayRender handler code and Calendar markup).
2) To populate individual day data in a calendar, use Calendar.VisibleDate (to filter DB results) in a Page.Load handler to load a data structure (such as a List<T>) with day data for the entire month. Then in a Calendar.DayRender handler, add appropriate records from the structure to the e.Cell.
3) To cause the new results to show up on the first page refresh after insertion, you should be able to get away with using a Response.Redirect to the current page after insertion. This will cause the page generation process to restart, but you will lose ViewState.
Edit: Here is a basic prototype of what I tried to describe above. Note that you could pre-fetch into any enumerable data type, I use a List<T> here.
//Page code-behind
public partial class Default2 : System.Web.UI.Page
{
List<DataObject> liCurrentMonth = new List<DataObject>();
protected void Page_Load(object sender, EventArgs e)
{
liCurrentMonth = DataObject.GetCurrentMonth(Calendar1.VisibleDate);
}
protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
foreach (DataObject item in liCurrentMonth)
{
if (item.date == e.Day.Date)
{
Literal lit = new Literal();
lit.Text = item.text;
e.Cell.Controls.Add(lit);
}
}
}
}
//Data layer object
public class DataObject
{
public DateTime date { get; set; }
public string text { get; set; }
public static List<DataObject> GetCurrentMonth(DateTime currentdate)
{
//Get items from the db here, based on currentdate parameter
//and populate the List<DataObject>.
return new List<DataObject>();
}
}
I'm not sure you'll get this to work. Its the page viewstate that remembers the value entered into textboxes etc. Viewstate is created just before the page renders. The Calendar DayRender event is called during the calendars rendering, and hence after viewstate has done its thing. Therefore the viewstate mechanism is not aware of the existance of the textboxes and so will not track their content.
Perhaps you could assign each textbox an ID based on the month and day number, on postback you could check for this control ID in the Request.Form collection and do something with the data?
Time for my daily ASP.NET question.
One of my pages shows all of our customer information from a customer table. I want the user to choose whether to see all customer records, or select a specific record from a list. So, my webpage has two radio buttons (show all customers, show specific customer), a listbox (full of customer names), and a formview control. The problem I'm having is getting the formview to update when I change modes via radio buttons or listbox selection (see code below).
Can anyone provide me with some pointers on how to do what I'm trying to do?
protected void Page_Load(object sender, EventArgs e)
{
UpdatePage ();
}
protected void RadioButtonShowAll_CheckedChanged(object sender, EventArgs e)
{
}
protected void RadioButtonShowSelected_CheckedChanged(object sender, EventArgs e)
{
}
protected void DropDownListCustomers_SelectedIndexChanged(object sender, EventArgs e)
{
RadioButtonShowSelected.Checked = true;
UpdatePage ();
}
protected void UpdatePage ()
{
if (RadioButtonShowAll.Checked)
SqlDataSource1.SelectCommand = "SELECT * FROM [Customer] ORDER BY [Company]";
else
SqlDataSource1.SelectCommand = "SELECT * FROM [Customer] WHERE ([CustomerID] = #CustomerID) ORDER BY [Company]";
FormView1.DataBind();
}
First, you only have the SelectedIndexChanged event wired up... In that case, what happens when you change the drop down box is first, Page_Load() fires--which calls UpdatePage(). Then, the event fires, which calls UpdatePage() again. The second time probably doesn't do what you expect.
The fix is to only call UpdatePage() from Page_Load() the first time the page is loaded, but not from postbacks:
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
UpdatePage();
}
Your page has to be updated on Client side, for it to show the new data. You'll need to use Javascript or AJAX and have some variable that keeps track of the need to refresh your page, this way you can send a request to update the page to the server when the Formview needs updating.
I want pass values between web user controls without writing any code to the main page which user controls are put on. I do something like that but after doing that I need to click double to pass the value.
The example of what I've done :
Department User Control (Code-Behind)
protected void Page_Load(object sender, EventArgs e)
{
int productId = ProductUserControl.selectedProductId;
... doing some bind work with productId
}
Product User Control
public static int selectedProductId;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void lvDepartments_ItemCommand(object sender, ListViewCommandEventArgs e)
{
if (e.CommandName == "selectDepartment")
{
selectedProductId = int.Parse(e.CommandArgument);
}
}
Thanks in advance...
In your Department User Control you are trying to get the value of selectedProductId before it is set in the Product User Control. That's why you don't get the value you expect until you postback twice.
You'll need to get it after the Product User Control sets it in the ItemCommand event. Perhaps placing the Department User Control code in the Page_LoadCompleted... though I'm not sure if that will work either.
Another way to do it is to have Product User Control set a public property in Department User Control instead of having Department User Control try to read a property in Product User Control.
The issue seems to be a Page Lifecycle issue.
http://www.robincurry.org/blog/content/binary/o_aspNet_Page_LifeCycle.jpg
I'm sure there's a better way than that as well.
Try using delegates to achieve this more cleanly, example here