I have 5 dropdownlist in asp.net.User selects 5 dropdownlist after that click to button.Button sends page to another page.If i go previous page dropdownlist selectedvalues and datas lose(it displays default values without selected values)
I tried below
Response.Redirect("PreviousPage.aspx");
datas losing is there any solution ?
Instead of using Response.Redirect(), you can change the PostBackUrl of the button to the target page, or use Server.Transfer(). Once there you should be able to access the properties you need from the Page.PreviousPage object.
Example using Server.Transfer:
Page1.aspx.cs:
protected void SubmitButton_Click(object sender, EventArgs e)
{
Server.Transfer("Page2.aspx");
}
Page2.aspx.cs:
protected void Page_Load(object sender, EventArgs e)
{
var addressDropdownSelectedValue = ((Page1)Page).PreviousPage.AddressDropdown.SelectedItem.Value; //or SelectedValue
}
With the ScriptManager in the AJAX control toolkit (you get this in 4.0+, I think maybe even in 3.5), you can add history points. You add a history point and use that value to rebuild the page state.
http://msdn.microsoft.com/en-us/library/cc488548%28v=vs.140%29.aspx
You can also strongly type the previous page if you want to grab values from it. You do this with <%# PreviousPage %> directive. Then in code you could use Page.PreviousPage.FindControl
Related
I am using different user controls with Modalpopupextender (within page, repeater etc.) and it took some time to figure all the tricks how to get this two togeather.
I have now ended up with the following problem
When I pass a param into user control
UserControl.ParamID = 1;
I am able to receive it in user control, but at the strange step of page cycle.
When I try to do
protected void Page_PreRender(object sender, EventArgs e)
{
throw new Exception(ParamID);
}
I get null for ParamID!?
But when I do
<% throw new Exception(ParamID); %>
from html, I get a correct ParamID value.
I tryied to store ParamID as ViewState, as a HiddeField, and it is always doing the same error.
Also, when I use this user control wihout mpe, just in regular aspx page, it all works just fine.
What is the catch?
I made researching about this subject I could not find proper answer.
In my default.aspx page, I have a treeview. Codes are in default.aspx like below:
protected void Page_Load(object sender, EventArgs e)
{
}
protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{
Control ucont;
if (TreeView1.SelectedNode.Value == "Yeni Dönem")
{
ucont = LoadControl("usercontrols/yenidonem.ascx");
PlaceHolder1.Controls.Add(ucont);
}
else
{
ucont = LoadControl("usercontrols/tabloktar.ascx");
PlaceHolder1.Controls.Add(ucont);
}
}
I load user controls dnynmicaly. User controls are have button control. I can not fire user control's button click when I load it dynamcally. How can I solve this ?
Thanks.
First of all, I would not recommend adding control dynamically later than in Page_Load event. Other things to remember is that You should add it on each page load and assign unique ID value the control that does not change between postbacks.
In this case, the easiest way would be to always add both controls to the page and show appropriate one using Visibility property.
If that's not suitable for You, try to move the code from TreeView1_SelectedNodeChanged to the Page_Load event and load appropriate control on each postback until it should be changed to another one.
I haven't tested this, so if You have any issues when using thise answer, let me know in the comments and I'll try to help.
I have in Site.Master:
<% if(Session["msg"]!=null) Response.Write(Session["msg"].ToString()); %>
I have also on submit form method:
protected void Send_Click(object sender, EventArgs e)
{
Session["msg"] = "Thx for email.";
Response.Redirect("~/Default.aspx");
}
But now when I refresh page or go to another page I still see "Thx for email." but user should see it only once.
You can clear out the Session["msg"] on Page_load (outside of the if(!isPostback))
Or you can create a label on the master page, access that through the child pages to put the message in there, and clear that one on Page load, this gets you away from using Session. Using a Label you can also set the cssClass, allowing bolding, color changes (red for errors, green for success, etc).
If you just want a plan message you could aways go with a literal control, less over head.
This is because Session variable having their value throghout the session.
Session["msg"]
will always have same value on all the pages in a session.
If you want that value should only be used for the page where you redirect then you can use querystring.
protected void Send_Click(object sender, EventArgs e)
{
Session["msg"] = "Thx for email.";
Response.Redirect("~/Default.aspx?msg='true'");
}
then on SiteMaster
<% if(Request.QueryString["msg"]!=null) Response.Write(Session["msg"].ToString()); %>
You have to set Session["msg"] = null after you show the message. Session lives in server at defualt of 20 min. If you do not set it null it will appeear
Try setting the Session["msg"] to null once it is printed on the page.
I've written a custom widget to allow a user to select a location from a database of locations. This is my first ASP.net custom control. It seemed like everything was working fine, but now there's a problem.
My control implements the RaisePostBackEvent function as follows:
public void RaisePostBackEvent(string eventArgument)
{
SelectedLocationId = eventArgument.Split('|')[0];
SelectedLocationDescription = eventArgument.Split('|')[1];
}
I wrote a test page and included the following in my ASP code:
<%= locationSelector.SelectedLocationId %>
That worked fine.
However, in my web application, the following code does not work:
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
Response.Write(locationSelector.SelectedLocationId);
// SelectedLocationId is null here!!!
}
When I run this code in the debugger, I see that my Page Load event fires before the Post Back event! Therefore, the data is not yet read from the postback. I know that using the MS provided text field control, the text is available at Page Load, so I think I must be doing something wrong.
How can I read the location that the user selected when the Page Load event fires? To clarify, I'm refering to the Page Load of a web application page.
You're setting SelectedLocationId on a postback event and at the same time you are trying to retrieve its value on the first load. SelectedLocationId will be null all right.
Try:
protected void Page_Load(object sender, EventArgs e)
{
if (locationSelector != null)
Response.Write(locationSelector.SelectedLocationId);
}
I'm using DotNetNuke 4.9.2 and am running into an odd issue.
I have a MultiView in the module that I'm developing, and in one of the views have a GridView that is bound to an ObjectDataSource.
In a separate view, i have several buttons that will switch the SelectMethod of the ObjectDataSource in the 2nd view and then set that view active. That all works fine, until the grid is sorted on the 2nd view - which causes a postback and the ODS somehow picks up its original SelectMethod. The SelectParameters that are assigned at the same time in the code-behind stick though.
Seems to me that the ObjectDataSource should be remembering the SelectMethod in viewstate, shouldn't it?
<asp:ObjectDataSource runat="server" ID="MyObjectDataSource" SelectMethod="MyFirstSelectMethod" TypeName="Whatever"></asp:ObjectDataSource>
protected void Button1_Click(object sender, EventArgs e)
{
MyObjectDataSource.SelectMethod = "MyNewMethod";
// more code here to change the parameters as well...
MyMultiView.SetActiveView(MyView2);
}
When I run that button click, the grid displays as expected. When I click on one of the column headers for the GridView and break in the page load to inspect the SelectMethod, it has reverted to the one declared in the markup.
Any suggestions as to what my problem could be here?
I'm guessing you've made sure that you're not resetting .SelectMethod when the page reloads?
I ended up working around the issue by just using a page property to hold the selectmethod, and then resetting it on each postback...
protected string MySelectMethod
{
get
{
return (string)ViewState["MySelectMethod"] ?? MySearchResultsDataSource.SelectMethod;
}
set
{
ViewState["MySelectMethod"] = value;
MySearchResultsDataSource.SelectMethod = value;
}
}
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
MySearchResultsDataSource.SelectMethod = MySelectMethod;
}
}
protected void MyButton_Click(object sender, EventArgs e)
{
MySelectMethod = "MyNewMethod";
}
Still not sure why that SelectMethod prop doesn't stick on a postback in nuke. I'm sure this has worked fine for me in straight asp.net projects in the past...