All I wish to do is simply click a button and the text in a textbox is automatically added as an item in the listbox. Shouldn't this be straight forward? Whilst debugging, the item is added and I can see the text by watching ListBox1.Items[0], but nothing is displayed in the web page. I had the same problem which i did not solve, in a console application! Can some one please guide me to what I am doing wrong?
protected void Button1_Click(object sender, EventArgs e)
{
ListBox1.Items.Add(new ListItem(TextBox1.Text));
}
Many thanks
Edit:
In a past project, I used the DataSource property, which worked perfectly. I have never yet managed to use the add Items! May be there is some sort of refresh or update?
Page code:
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:ListBox ID="ListBox1" runat="server" Height="150px" Width="295px"></asp:ListBox>
<asp:UpdatePanel ID="updatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" Text="Submit" OnClick="Button1_Click" />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</ContentTemplate>
</asp:UpdatePanel>
Looks like your listbox is outside of the update panel. Pop it inside the update panel:
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList>
<asp:Button ID="Button1" runat="server" Text="Button" onclick="AddItem" />
</ContentTemplate>
</asp:UpdatePanel>
You have to move the ListBox into the UpdatePanel, otherwise it will not be updated.
The reason for that is, that ASP.NET is sending the whole HTML of the UpdatePanel back to the client. Since the ListBox is not part of the UpdatePanel, it won't be updated.
Related
Currently have a dropdownlist located inside of an Updatepanel. I have an event handler setup for the selection change event. PartialPageRendering is set to true in the script manager. The first time I select an item in the dropdownlist the whole page is reloaded. After that it only triggers the event like it should. I am capturing the PagePostBack event in the code, but the first time the index changes, this does not get set, after that it works as expected. Any ideas? Thanks!
<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true"></asp:ScriptManager>
<div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="conditional">
<ContentTemplate>
<div style="text-align:center">
<asp:DropDownList ID="DropDown1" runat="server" AutoPostBack="True" OnSelectedIndexChanged ="DropDown1_SelectedIndexChanged" Font-Size = "48">
</asp:DropDownList>
<br />
</div>
</ContentTemplate>
<Triggers>
</Triggers>
</asp:UpdatePanel>
</div>
I have two nested Gridviews, the parent is for Posts and child is for Comments. I want to update Post and Comments with a Time Interval so Im using an asp.net Timer. My problem is that a TextBox that is in the first Gridview loses focus when timer Ticks. I searched the web a lot, one possible solution was to take the textbox out of the UpdatePanel but in this situation I can't take out the textBox. Please help me, here is my code.
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:Timer ID="Timer1" Interval="10000" OnTick="Timer1_Tick" runat="server">
</asp:Timer>
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
</Triggers>
<ContentTemplate>
<%--post GridView--%>
<asp:GridView ID="posts" runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<%--Comments Gridview--%>
<asp:GridView ID="comments" runat="server"></asp:GridView>
<%--a Textbox and bUtton For sending new Comment--%>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</ContentTemplate>
</asp:UpdatePanel>
protected void Timer1_Tick(object sender, EventArgs e)
{
posts.DataSource = GetData();
posts.DataBind();
}
I was going to type a similar answer to this, but it appears it has already been explained here - https://stackoverflow.com/a/22014420/2248290
The key point being: "An update panel takes focus away as it posts back"
I have an aspx page in which I have Ajax UpdatePanel which has a AJAX Tabcontainer which has 5 tab. In First tab I have a DropDownList for ProductID. In the second tab I have used a UserControl whose parameter needs to be reflected based on productID. I want to Access the DropDownList ProductID in the user control which I am not getting. Part of my code is
DropDownList IDList = (DropDownList)(this.Parent.FindControl("ProductID");
this is not working and I am getting NULL. I also have Tried
DropDownList IDList = (DropDownList)(this.Page.FindControl("ProductID");
Please tell me how I can do this.
As asked Part of necessary code is
<asp:UpdatePanel ID="UpdatePanelTankFormula" runat="server">
<ContentTemplate>
<asp:tabcontainer id="TabContainerTankFormula" AutoPostBack="true" runat="server" OnClientActiveTabChanged="clientActiveTabChanged" activetabindex="0" style="width:100%;">
<asp:TabPanel ID="InputDataTab" runat="server" HeaderText="Data Input">
<ContentTemplate>
<asp:DropDownList id="TankNameCombo" DataTextField="TankName" runat="server" AutoPostBack="true" DataValueField="customertankid" width="200px" onclick="javascript:SetHiddenField();"> </asp:DropDownList>
</ContentTemplate>
</asp:TabPanel>
<asp:TabPanel ID="LacticAcidAdditionTab" runat="server" HeaderText="Lactic Acid Addition">
<ContentTemplate>
//My user control
<UC:TankNote runat="server" ID="LaticTankNotesUC" GetNoteType="LAC" MEQMode="False"></UC:TankNote>
</ContentTemplate>
</asp:TabPanel>
</asp:tabcontainer>
<ContentTemplate>
</asp:UpdatePanel>
Now in the Code Behind of this User Control I want to access this DropDownList, which I am not getting. For the fix I have define a Public function that return the value of this list. But its a fix not solution.
You will have something like this in tab control.
<cc1:TabContainer ID="TabContainer1" runat="server">
<cc1:TabPanel ID="TabPanel1" runat="server">
<ContentTemplate>
<asp:DropDownList id="dropdownlist1" runat="Server"/>
</ContentTemplate>
</cc1:TabPanel>
So first you need to find tabPanel1 then find dropdownlist1 like following.
TabContainer TabContainer1= (TabContainer)(this.Page.FindControl("TabContainer1");
if (TabContainer1!=null){
TabPanel TabPanel1= (TabPanel)(this.TabContainer1.FindControl("TabPanel1");
if(TabPanel1 !=null){
DropDownList dropdownlist1= (DropDownList)(this.TabPanel1.FindControl("dropdownlist1");
}}
I have a page name ask.aspx
I have 4 list views in that page which are binding at the time of page load event.
now when ever i click on the items of list view i get the whole page refreshed.
I have used the update panel but for some reasons it is not working
The code for the same is given below.
aspx page
enter code here
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel2" runat="server" ChildrenAsTriggers="true" UpdateMode="Conditional">
<ContentTemplate>
<fieldset>
<legend><asp:Label ID="Label1" runat="server"></asp:Label></legend>
<ul class="tags">
<asp:ListView ID="ListView1" runat="server" OnItemCommand="ListView1_ItemCommand" >
<ItemTemplate>
<li><asp:LinkButton ID="LinkButton2" runat="server" CommandArgument='<%# Eval("CategoryId") %>'><%# Eval("Name") %></asp:LinkButton></li>
</ItemTemplate>
</asp:ListView>
</ul>
</fieldset>
</ContentTemplate>
<Triggers></Triggers>
</asp:UpdatePanel>
ending the content template and update panel.
similarly for the other three listviews.
at cs page
some calculations are taking place.
Now i dont want the page to refresh every time.
what should be done.
please suggest.
Remove childrenastrigger property and set updatemode=always
I have an Update panel within a wizard:
<asp:WizardStep ID="WizardStep2" runat="server" StepType="Auto"
Title="Set the number of users required.">
...
<asp:UpdatePanel ID="UpdatePanel2" UpdateMode="Always" runat="server">
<ContentTemplate>
<asp:Label runat="server" ID="ProgressInd" Text="Progress..." />
<asp:Button runat="server" OnClick="GoButton_Click" ID="ProgressBtn" Text="Go" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:WizardStep>
...
protected void GoButton_Click(object sender, EventArgs e)
{
ProgressInd.Text = "Progress... Moving";
}
When I take the update panel out of the wizard it works nicely but inside the wizard the click event just won't fire. I'm using Firefox to test, but IE doesn't work either. Any ideas or help appreciated.
For the record. Paolo spotted my problem. There were page validators that were preventing the event from firing.