I have the following code that opens a hyperlink in a different frame from code behind using the function ClientScript.RegisterStartupScript. The hyperlink was priory retrieved from a database and assigned to a label.
public void OpenWindow()
{
Formview_CurrentSelectedProcess.DataBind();
string url = (Formview_CurrentSelectedProcess.FindControl("LabelLink") as Label).Text;
string s = "window.open('" + url + "', 'main');";
Test.Text = s;
ClientScript.RegisterStartupScript(this.GetType(), "script", s, true);
}
This works perfect. Then I implemented a Querystring on that page. The Request Parameter is passed correctly and the hyperlink is opened on Pageload the way I expected. BUT: the next time this method is called, the hyperlink that will be opened, is the one belonging to the record specified in the Querystring Parameter. I placed a label inside to check if the correct parameter 's' is passed to ClientScript.RegisterStartupScript() and it is!!!
The mistake occurs with that function in case that the page had been loaded with a Querystring Parameter (eg.aspx?ID=324) Loading that same page without that parameter works perfect.
What happens? Why is ClientScript.RegisterStartupScript returning the old result, although it's input parameter has changed?
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
PopulateRootLevel();
string GetID = Request.QueryString["ID"];
if (String.IsNullOrEmpty(GetID))
{
}
else
{
InputNodeToOpen.Text = GetID;
ButtonClick_transmit(button1, EventArgs.Empty);
InputNodeToOpen.Text ="";
IDNodesToBeOpened.Text = "";
}
}
Any hints on that?
Martin
OK. Found the mistake:
After placing all actions in the page_load method inside separate brackets it works. I thought they were already assigned to a no-post-back situation; but they were NOT. The brackets are needed. So it must be:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
PopulateRootLevel();
string GetStructure = Request.QueryString["Structure"];
if (String.IsNullOrEmpty(GetStructure))
{
}
else
{
InputNodeToOpen.Text = GetStructure;
ButtonClick_transmit(button1, EventArgs.Empty);
InputNodeToOpen.Text = "";
IDNodesToBeOpened.Text = "";
}
}
}
I'm wondering what is my issue on passing a variable from page to page using asp.net session.
I've stripped the code down to just one text box to see whats going on. I'm just trying to take the value of a text box and display it on a confirmation page. When the button is clicked it transfers me to the second page but there label is blank. Yes my post back url is pointing to the second page.
Here is the button click:
protected void submit_Click(object sender, EventArgs e)
{
string name = txtFirstName.Text.Trim();
Session["name"] = name;
}
Here is the page load of the second page:
protected void Page_Load(object sender, EventArgs e)
{
lblName.Text = (string)(Session["name"]);
}
Unless I've been looking at this to long and missed something. I've already read "How to: Read Values from Session State" from MSDN.
You say that you've set the PostBackUrl to your second page. If you're going to do it that way, you need to use Page.PreviousPage to get access to your textbox. But this is the easiest way:
Firstly, leave the PostBackUrl alone. Setting the PostBackUrl to your second page means that you're telling the SECOND PAGE to handle your button click, not the first page. Hence, your session variable never gets set, and is null when you try to pull it.
This should work for ya.
And yes, you can also do this with a QueryString, but if its something that you don't want the user to see/edit, then a Session variable is better.
protected void submit_Click(object sender, EventArgs e)
{
string name = txtFirstName.Text.Trim();
Session["name"] = name;
Response.Redirect("PageTwo.aspx");
}
Then in the second page (You don't REALLY need the ToString()):
protected void Page_Load(object sender, EventArgs e)
{
if (Session["name"] != null)
{
lblName.Text = Session["name"].ToString();
}
}
EDIT -- Make sure that your button click actually gets fired. Someone can correct me wrong on this, as I do most of my work in VB.NET, not C#. But if you don't specify the OnClick value, your function won't get called.
<asp:Button ID="Button1" runat="server" Text="Click Me!" OnClick="submit_Click" />
The code you have posted looks fine, so your problem is probably with setup.
Check this link ASP.NET Session State Overview and pay particular attention to the sections on Cookieless SessionIDs and Configuring Session State.
I don't think you added the session. This is how I have done mine.
First Page
protected void btnView_Click(object sender, EventArgs e)
{
foreach (ListItem li in lbxCheckDates.Items)
{
if (li.Selected == true)
{
lblMessage.Text = "";
string checkDate = lbxCheckDates.SelectedItem.Text;
Session.Add("CheckDates", checkDate);
Page.ClientScript.RegisterStartupScript(
this.GetType(), "OpenWindow", "window.open('Paystub.aspx','_newtab');", true);
}
}
}
Second Page
protected void Page_Load(object sender, EventArgs e)
{
string checkDate = (string)(Session["CheckDates"]);
//I use checkDate in sql to populate a report viewer
}
So with yours, I think you need..
protected void submit_Click(object sender, EventArgs e)
{
string name = txtFirstName.Text.Trim();
Session.Add("Name", name);
}
I think what you have in the second page should work, but if it doesn't, add ToString() to it like..
lblName.Text = (string)(Session["name"]).ToString();
Let me know if this helps!
Are you doing a redirect after setting the session variable on the first page, if so you it will not work correctly (unless you know the trick). Checkout this article on making it work. Basically, the way to make this work is to the overload redirect method.
Response.Redirect("~/newpage.aspx", false);
The false parameter prevents .net from terminate processing on the existing page (that actually writes out the session state)
For Second Page
protected void Page_Load(object sender, EventArgs e)
{
if (Session["value"] != null)
{
Label1.Text = Session["value"].ToString();
}
else
{
Label1.Text = "Sorry,Please enter the value ";
}
}
You can use Server.Transfer() instead of Response.Redirect()
For first page, use this:
protected void Button1_Click(object sender, EventArgs e)
{
string value = TextBox1.Text;
Session["value"] = value;
Response.Redirect("~/Sessionpage.aspx");
}
I have a GridView with a search textbox and a Search Button, Once I try to search some records by Location, by Name, etc. I have a list of records that shows properly, if I select one record and I decide that is not the one I have and I click a back button that I include , my search is lost and I have to search again.
I understand that I have to create a session to solve this, but I am getting lost. This is what I have so far. Any idea?
protected void search_button_Click(object sender, ImageClickEventArgs e)
{
gvCompanyList.PageIndex = 0;
SearchForCompanies();
//Save search criteria into a session
Session["SearchString"] = tbSearchTerm.Text;
}
protected void gvCompanyList_PreRender(object sender, EventArgs e)
{
GridViewRow pagerRow = (GridViewRow)gvCompanyList.BottomPagerRow;
if (pagerRow != null && pagerRow.Visible == false)
pagerRow.Visible = true;
// To Call the session
String searchCriteria;
if (String.IsNullOrEmpty(tbSearchTerm.Text))
{
if (!String.IsNullOrEmpty(Session["SearchString"].ToString()))
{
searchCriteria = Session["SearchString"].ToString();
}
}
It looks as though you are on the right track. You just need to create a button now to execute the search using your session variable if it is clicked.
public void Submit1_Click(Object sender, EventArgs E)
{
string strheadlinesid1 = string.Empty;
if (!IsPostBack)
{
if (!string.IsNullOrEmpty(Convert.ToString(Request.QueryString["folder"].ToString())))
{
strheadlinesid1 = Request.QueryString["folder"].ToString();
}
}
string URL = "view4.aspx?value="+strheadlinesid1;
Response.Redirect(URL);
}
This is a function I'm using but when I pass strheadlinesid1, "value" variable in URL is getting nothing.Why Is it happening.Is there any wrong in this approach.
On the button click, the page will be in the postback state and your condition will be false if (!IsPostBack) so it will not enter into the block and hence the value will not be assigned to strheadlinesid1
this block
if (!IsPostBack)
{
if (!string.IsNullOrEmpty(Convert.ToString(Request.QueryString["folder"].ToString())))
{
strheadlinesid1 = Request.QueryString["folder"].ToString();
}
}
should be
if (!string.IsNullOrEmpty(Convert.ToString(Request.QueryString["folder"].ToString())))
{
strheadlinesid1 = Request.QueryString["folder"].ToString();
}
A button click is a postback so strheadlinesid1 will not be assigned to and will be empty.
You need to remove the check for IsPostback, since button click events will usually be executed as postback events.
public void Submit1_Click(Object sender, EventArgs E)
{
string strheadlinesid1 = string.Empty;
if (!string.IsNullOrEmpty(Convert.ToString(Request.QueryString["folder"].ToString())))
{
strheadlinesid1 = Request.QueryString["folder"].ToString();
}
string URL = "view4.aspx?value="+strheadlinesid1;
Response.Redirect(URL);
}
Because Button click is a postback and the code to read "folder" query string doesn't execute if it is a postback?
So the value of "value" is always empty.
Remove the check for !IsPostback if that is what you wanted.
On ItemUpdating, I am able to retrieve field values, but I am not able to retrieve only updated values.
Is there a better way to do this than the method below?
protected void fwHotelDetails_ItemUpdating(Object sender, FormViewUpdateEventArgs e)
{
TextBox tbName = (TextBox)fwHotelDetails.Row.FindControl("input_name");
MessageLabel.Text = "This works..." + tbName.Text;
}
Yea. Event handler's second parameter (FormViewUpdateEventArgs e) has following properties:
Keys
NewValues
OldValues
More info on msdn
Hope this helps