DropDownList's SelectedIndexChanged() Event fills the ListBox on the page. Obviously this posts the page back to the server. Is there any way to make it happen without full postback?
protected void ddlTablo_SelectedIndexChanged(object sender, EventArgs e)
{
List<string> list = new List<string>();
ListBox1.Items.Clear();
var columnNames= from t in typeof(Person).GetProperties() select t.Name;
foreach (var item in columnNames)
{
list.Add(item);
}
ListBox1.DataSource = list;
ListBox.DataBind();
}
You could put the DropDownList into an <asp:UpdatePanel> and set the trigger to the SelectedIndexChanged event of the DropDownList.
Something like this (don't forget the script manager)
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:DropDownList ID="drop1" runat="server" OnSelectedIndexChanged="ddlTablo_SelectedIndexChanged" />
</ContentTemplate>
<Triggers>
<asp:AsyncPostbackTrigger ControlID="drop1" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
You can send ajax call, using asp.net UpdatePanel or use jQuery ajax. This wont do postback and your whole page wont get refreshed.
The UpdatePanel is quite straight forward and easy to use. ASP.net ajax will generate the asyn calls for you whereas jQuery ajax will probably need you to render html using javascript.
In the code snippet below, add this parameter: AppendDataBoundItems="True"
<asp:DropDownList ID="ddlGroupNameFilter"
runat="server"
AutoPostBack="true"
AppendDataBoundItems="true"
OnSelectedIndexChanged="ddlLeadgroupName_SelectedIndexChange">
</asp:DropDownList>
Related
I am doing a project in asp.net. i have a panel which contains some field like txtbox ,buttons etc..I want to use jquery event on a asp.net button click which will open this panel by using jquery show() function and also perform some tasks in server side. Please help me.
The code is :
protected void btninsertfordeo_Click(object sender, EventArgs e)
{
// GridViewforcontact.Enabled = false;
PanelForInsert.Visible = true;
colvisible = true;
txtfaxnoextra.Focus();
if (colvisible == true)
{
GridViewforcontact.Columns[9].Visible = false;
}
colvisible = false;
}
You can use the OnClientClick property of the button to call your client-side function and OnClick to call your server code
<asp:Button ID="btninsertfordeo" runat="server" OnClientClick="functionToShowPanel()" OnClick="hlkContinue_Click" Text="Click"></asp:Button>
<script>
functionToShowPanel(){
$('#pnlToShow').show()
}
</script>
or without using OnClientClient you can probably do:
$('#<%=btninsertfordeo.ClientID %>').click(function(){
$('#pnlToShow').show()
}
Another option would be to use an UpdatePanel instead of jquery to show/hide elements on the page. This way you can control the visibility of your div from your code-behind. Add all the dynamic elements within the UpdatePanel's ContentTemplate and add your button as an AsynPostbackTrigger for the UpdatePanel to enable dynamic updating of our page.
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btninsertfordeo" EventName="click" />
</Triggers>
<ContentTemplate>
<asp:Panel ID="PanelForInsert" runat="server" Visible="false">
//Your textboxes, buttons etc goes here
</asp:Panel>
<asp:Button ID="btninsertfordeo" runat="server" Text="Click" OnClick="btninsertfordeo_Click"></asp:Button>
</ContentTemplate>
</asp:UpdatePanel>
Here are links to documentation that will help you in understanding and implementing an UpdatePanel:
Introduction to the UpdatePanel
UpdatePanel Control Overview
UpdatePanel Class
I have a repeater with a RadioButtonList inside the ItemTemplate, but when the RadioButtonList.OnSelectedIndexChanged event fires it generates a full postback. What have I done wrong in my code below? How can I get the OnSelectedIndexChanged to generate an Async Postback?
<asp:UpdatePanel runat="server" ID="UpdatePanel2">
<ContentTemplate>
<asp:Repeater ID="Repeater1" runat="server" DataSourceID="sqlOptions">
<ItemTemplate>
<asp:UpdatePanel runat="server" ID="pnlA">
<ContentTemplate>
<strong>
<%# Eval("Name") %></strong><br />
<asp:RadioButtonList ID="RadioButtonList1"
DataSourceID="sqlOptionValues" runat="server"
DataTextField="id" DataValueField="Id" AutoPostBack="true"
OnSelectedIndexChanged="LoadPrice"
ValidationGroup="options" />
<asp:RequiredFieldValidator ID="RequiredFieldValidator1"
ForeColor="Red" runat="server"
ControlToValidate="RadioButtonList1"
ErrorMessage="Required Field"
ValidationGroup="options" />
<asp:SqlDataSource ID="sqlOptionValues" runat="server"
ConnectionString="<%$ ConnectionStrings:
ConnectionString6 %>"
SelectCommand='<%# "SELECT DISTINCT OptionValue.Name,
OptionValue.Id FROM CombinationDetail
INNER JOIN OptionValue
ON CombinationDetail.OptionValueId = OptionValue.Id
WHERE (OptionValue.OptionId =" +
Eval("Id") + ")" %>'>
</asp:SqlDataSource>
<br />
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
</asp:Repeater>
</ContentTemplate>
</asp:UpdatePanel>
Many thanks for any help :)
This is a real-world use case. I have a page with Repeaters, Ajax Accordions inside of other Accordions, Update Panels inside other Update panels, you name it. The page works great, except when I want to update one of the Accordion panels with my RadioButtonList (RBL). Even with the RBL inside an update panel, it causes a postback of the entire page. I tried everything. I finally realized it wasn't me when I noticed my buttons would work just fine. I figure it must be a bug in either the framework or the Ajax Control Toolkit. I did find people reference this link all over the web (http://blog.smarx.com/posts/the-case-of-the-radiobuttonlist-half-trigger.aspx), but this link from 2007 is dead now and probably no longer applicable, so that's no help.
What I ended up doing was going with what works - that submit button. All I did was add an onclick attribute to the RBL to call a hidden button. Now you don't want to set the button to Visible=false because then the button won't appear in the generated markup. Instead, set the button's style to display:none; so that no one will see this hack, because yes, that's what this workaround is - it's a hack, but simple and just as effective as what you'd expect. Don't forget to remove the Autopostback="True" from your RBL.
CAVEAT: Because I'm using a hacked button for the onclick event, it's possible for the user to click in the area of the RBL, but not actually select an item. When this happens, our onclick triggers an AsyncPostBack and the codebehind logic will be processed, so please keep that in mind. To give you an idea of what I mean: all the Page_Load() events will be called, but rbl_Questions_SelectedIndexChanged() won't be if they happen to click in the area of the RBL without actually selecting an item. For my purposes this causes no issues in my logic and has no effect on the user.
Here's the Code:
Somewhere In the .Aspx Page:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:RadioButtonList ID="rbl_Questions" runat="server"
OnSelectedIndexChanged="rbl_Questions_SelectedIndexChanged">
</asp:RadioButtonList>
<asp:Button ID="btn_rbl_Questions" runat="server" style="display:none;"/>
<asp:Label ID="lbl_Result" runat="server" Text="" Visible="false">
</asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
In the Page_Load() event:
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == false)
{
//Instead of using the AutoPostback of the RBL, use this instead.
rbl_Questions.Attributes.Add("onclick",
"document.getElementById('"
+ btn_rbl_Questions.ClientID
+ "').click();");
//Bind your RBL to a DataSource, add items programmatically,
// or add them in the aspx markup.
}
}
In the rbl_Questions_SelectedIndexChanged() event:
protected void rbl_Questions_SelectedIndexChanged(object sender, EventArgs e)
{
//Your code here.
//My code unhid the lbl_Result control and set its text value.
}
Update 05/24/2011
The above "hack" is no longer necessary (I am leaving it above since this was marked as the answer by the author). I have found the best way to do this, thanks to this SO Answer:
Updatepanel gives full postback instead of asyncpostback
The code is much simpler now, just remove what I put in the Page_Load() method and remove the Button I used in the Aspx page and add ClientIDMode="AutoID" and AutoPostBack="True" to the control you want the UpdatePanel to capture.
Somewhere In the .Aspx Page:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:RadioButtonList ID="rbl_Questions" runat="server"
ClientIDMode="AutoID" AutoPostBack="true"
OnSelectedIndexChanged="rbl_Questions_SelectedIndexChanged">
</asp:RadioButtonList>
<asp:Label ID="lbl_Result" runat="server" Text="" Visible="false">
</asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
MS changed how ClientID's are generated in .net 4.0 from "AutoID" to "Predictable" and I guess the ScriptManager or UpdatePanel's weren't updated correctly to use it. I can't find documentation on why that is anywhere or if it was left that way by design.
I seriously don't miss winforms.
Try this:
<asp:UpdatePanel runat="server" UpdateMode="Conditional" ID="pnlA">
You'll also need to setup
<Triggers>
//radio buttons
</Triggers>
Not sure how you'll do that since it's a dynamically built list.
I have a complicated case, so I can't post it.
I have two UpdatePanels with two UserControls inside them, like the following:
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<A:u1 ID="u1" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<A:u2 ID="u2" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
In this sample, the PostBack in u1 doesn't effect on u2. but in my code the PostBack in the first UserControl made a PostBack in the second.
What are the expected reasons ??
Thanks for the help.
This is by design: when a partial postback occurs, the whole page is rendered again even if only part of the resulting markup is sent to the client. Thus, both your user controls go through their lifecycles again, even if only u1 is updated.
If you want to detect that case, you can use the IsInAsyncPostBack property:
protected void Page_Load(object sender, EventArgs e)
{
if (ScriptManager.GetCurrent(Page).IsInAsyncPostBack) {
// This is a partial postback.
}
}
I have placed a user control inside update panel after doing asynchronous postback of page associated js file of that user control is not working so that is there any method to exclude a control from updatepanel in another word i don't want to post that user control.
<asp:UpdatePanel ID="upPnlAnswerList" runat="server">
<ContentTemplate>
// another code that required to placed inside updatepanel
<div id="miancontainer" class="containerr"
<klmsuc:Share ID="shareUserControl" runat="server" />
// another code that required to placed inside updatepanel
</div>
Use a PostBackTrigger to perform exclusion rather than having to specify a large number of includes.
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:LinkButton ID="lnkExport" runat="server" OnClick="lnkExport_Click" Text="Export Data"></asp:LinkButton>
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="lnkExport" />
</Triggers>
</asp:UpdatePanel>
Set UpdateMode=Conditional and provide exclusive Triggers for the UpdatePanel.
See:
http://msdn.microsoft.com/en-us/library/bb386454.aspx
you must add some controls in code behind and in the right event and register it for exclusion(postback) instead and AsyncPostBack which is a ajax call.
ScriptManager.GetCurrent(this).RegisterPostBackControl(btnAdd);
https://stackoverflow.com/a/23036830/184572
protected void grdExpense_RowCreated(object sender, GridViewRowEventArgs e)
{
LinkButton btnAdd = (LinkButton)e.Row.Cells[0].FindControl("btnAdd");
if (btnAdd != null)
{
ScriptManager.GetCurrent(this).RegisterPostBackControl(btnAdd);
}
}
look for another similar page which excludes all the controls in a gridview
http://www.aspsnippets.com/Articles/Assign-PostBack-Trigger-Full-PostBack-for-LinkButton-inside-GridView-within-AJAX-UpdatePanel-in-ASPNet.aspx
private void RegisterPostBackControl()
{
foreach (GridViewRow row in GridView1.Rows)
{
LinkButton lnkFull = row.FindControl("lnkFull") as LinkButton;
ScriptManager.GetCurrent(this).RegisterPostBackControl(lnkFull);
}
}
I have an ASP page with an asp:DropDownList (with AutoPostBack="true") so that when the user changes it, it reload the appropriate data.
Under that control i have a list of UserControls, that includes a tinymce editor (tied to an asp:TextBox) and an asp:ImageButton to save the data.
When clicking on the ImageButton, the applications send the postback data via ajax to the same page (__EVENTARGUMENT, __EVENTTARGET, etc...). Why does it load that ajax page, and how do i prevent it? I'm updating the value in the DB in the OnClick event handler on the ImageButton, so all I need to do, is get ride of that ajax call.
Any ideas?
Solution 1
<asp:ImageButton ID="btn" runat="server" ImageUrl="~/images/yourimage.jpg"
OnClientClick="return false;" />
OR
Solution 2
<asp:ImageButton ID="btn" runat="server" ImageUrl="~/images/yourimage.jpg"
OnClientClick="yourmethod(); return false;" />
In addition (solution 2), your javascript method may be in this form
<script type="text/javascript">
function yourmethod() {
__doPostBack (__EVENTTARGET,__EVENTARGUMENT); //for example __doPostBack ('idValue',3);
}
</script>
in code behind
protected void Page_Load(object sender, System.EventArgs e)
{
if (this.IsPostBack) {
string eventTarget = this.Request("__EVENTTARGET") == null ? string.Empty : this.Request("__EVENTTARGET");
string eventArgument = this.Request("__EVENTARGUMENT") == null ? string.Empty : this.Request("__EVENTARGUMENT");
}
}
You've not stated you're using an UpdatePanel but this is presumably how you've implemented ajax calls. If so you need to add a trigger to exclude the imagebutton event from ajax:
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:PostBackTrigger ControlID="ImageButton" />
</Triggers>
<ContentTemplate> </ContentTemplate>
</asp:UpdatePanel>