First.ascx
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
public void View(object sender, EventArgs e)
{
string name = txtName.Text;
}
Second.ascx
<button type="button" runat="server" onserverclick="Button1_click">View</button>
protected void Button1_click(object sender, EventArgs e)
{
UserControl uc = (UserControl)LoadControl("First.ascx");
uc.View(sender, e);
}
Why "txtName" always null, if I create a Button on First.ascx it's normal, but if I call function from Second ascx always null value.
You should look postback. Because every usercontrols page_load run afeter postback. You can catch your text value after postback in page_load.
if (!IsPostBack)
{
//Catch your value
}
Related
I have a FormView with data(DataSource,DataBind) that I fill with value='<%# Eval("Name") %>' , but after I'm changing the text in TextBox and press update button I see the same value that before, I cant see new value that I have typed.
What I am missing here?
my html
<asp:FormView ID="MainFormTemplate" runat="server">
<ItemTemplate>
<li class="li_result" runat="server">
<div class="col-3">
<input id="txt_Name" runat="server" value='<%# Eval("Name") %>'>
</div>
</li>
</ItemTemplate>
</asp:FormView>
<asp:Button id="btn_Update" runat="server" OnClick="btn_Update_Click" Text="Update" />
Server side
protected void Page_Load(object sender, EventArgs e)
{
using (DB_MikaDataContext data = new DB_MikaDataContext())
{
MainFormTemplate.DataSource = data.File_Projects.Where(x => x.Num_Tik.Equals("12")).ToList();
MainFormTemplate.DataBind();
}
}
public void btn_Update_Click(object sender, EventArgs e)
{
//using System.Web.UI.HtmlControls
HtmlInputText twt = (HtmlInputText)MainFormTemplate.FindControl("txt_Name");
string text = twt.Value;//i see old value ,not new one that i typed in text box
}
In every postback, you are always getting the old value from your database. The solution is check if the page is being rendered for the first time (!IsPostBack) then set your MainFormTemplate's DataSource else if is being loaded in response to a postback (IsPostBack) get the txt_Name's value like this:
HtmlInputText twt;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
using (DB_MikaDataContext data = new DB_MikaDataContext())
{
MainFormTemplate.DataSource = data.File_Projects.Where(x => x.Num_Tik.Equals("12")).ToList();
MainFormTemplate.DataBind();
}
}
else
{
twt = MainFormTemplate.FindControl("txt_Name") as HtmlInputText;
}
}
protected void btn_Update_OnClick(object sender, EventArgs e)
{
string text = twt.Value; // You will get the new value
}
with Page_Load executing every postback, you are always writing value from database (?), and value sent from browser is lost (although still exist in Page.Request.Form member).
In ASP.NET, When a page is submitted, the Page_Load event runs before the button click event. So, the textbox value gets repopulated with its original value before the click event looks at that value.
If this is the situation, then you can wrap the code that assigns the value to the textbox in an if block like this:
if (!IsPostBack)
{
HtmlInputText twt = (HtmlInputText)MainFormTemplate.FindControl("txt_Name");
string text = twt.Value;
}
Hope this helps you.
I've a form (mainpage.aspx), on which there's a button called 'Cancel'. Here's the code for the button:
<asp:LinkButton ID="btnCancel" runat="server" Text="Cancel" CssClass="btn btn-default" OnClick="btnCancel_Click" />
and the called function
protected void btnCancel_Click(object sender, EventArgs e)
{
Response.Redirect("EventList.aspx");
}
So as you can see, what the button do is simple. Just go to another page. But it seems here that doesn't happen. Every time I click the Cancel button, first it will try to load the code
Response.Redirect("EventList.aspx");
but then somehow it will try to execute the codes below:
if (hdnEventId.Value != "" && hdnEventId.Value != "0")
{
LoadEvent();
}
I know this because I put a breakpoint on Response.Redirect("EventList.aspx"); and after that I step into the code above
btw the codes above are located inside
protected void Page_Load(object sender, EventArgs e)
inside the file mainpage.aspx.cs
That's because Page_Load is called on any postback and you're actually doing a postback by clicking Cancel. The solution is to wrap your non-postback specific code in a IsPostBack check:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (hdnEventId.Value != "" && hdnEventId.Value != "0")
{
LoadEvent();
}
}
}
I have a dropdown list inside a asp:repeater item template.
how can I get its value on button click event.
<asp:Repeater runat="server" ID="WorkflowListAfter" onitemcreated="WorkflowListAfterItemCreated">
<ItemTemplate>
<asp:DropDownList ID="ddlWorkflowMembers" runat="server" DataTextField="MemberName" DataValueField="MemberID">
</ItemTemplate>
</asp:Repeater>
protected DropDownList ddlWorkflowMembers = new DropDownList();
protected void WorkflowListAfterItemCreated(object sender, RepeaterItemEventArgs e)
{
ddlWorkflowMembers = (DropDownList) e.Item.FindControl("ddlWorkflowMembers");
}
protected void BtnSaveClick(object sender, EventArgs e) {
if (ddlWorkflowMembers.SelectedItem == null) return;
}
the code above is working at first time but after postback ddlWorkflowMembers is always null expersion.
Assuming that BtnSave is also inside the repeater.
You get the RepeaterItem by casting the button's NamingContainer. Then you can use FindControl to get the reference to your DropDownList:
protected void BtnSaveClick(object sender, EventArgs e) {
var btn = (Button)sender;
var item = (RepeaterItem)btn.NamingContainer;
var ddl = (DropDownList) item.FindControl("ddlWorkflowMembers");
// ...
}
If the button is outside of the repeater and you want to save all items, you need to loop through all:
protected void BtnSaveClick(object sender, EventArgs e) {
foreach(RepeaterItem item in WorkflowListAfter.Items)
{
var ddl = (DropDownList) item.FindControl("ddlWorkflowMembers");
// ...
}
}
I have a TextBox control inside a panel and this panel is inside DataList ItemTemplate.
After firing the ItemCommand event, everything works fine except that the TextBox.Text property is always an empty string "" although there is some text in it.
I tried several ways but without success. I would really appreciate if someone can assist me with this. Simplified code is shown below.
Thank you!
ASPX page:
<asp:DataList ID="dlDataList" runat="server" onitemcommand="dlDataList_ItemCommand">
<ItemTemplate>
<asp:Panel ID="pnlReply" runat="server" Visible="False">
<asp:TextBox ID="txtTextBox" runat="server"></asp:TextBox><br />
<asp:LinkButton ID="lnkbtnSend" CommandName="Send" runat="server">Send</asp:LinkButton>
</asp:Panel><br />
<asp:LinkButton ID="OpenPanel" CommandName="OpenPanel" runat="server">Open panel</asp:LinkButton>
</ItemTemplate>
</asp:DataList>
</asp:Content>
ASPX.CS Page code behind
protected void Page_Load(object sender, EventArgs e)
{
FillDataList();
}
private void FillDataList()
{
List<string> list = new List<string>();
list.Add("First");
list.Add("Second");
list.Add("Third");
dlDataList.DataSource = list;
dlDataList.DataBind();
}
protected void dlDataList_ItemCommand(object source, DataListCommandEventArgs e)
{
if (e.CommandName == "OpenPanel")
{
Panel pnlReply = (Panel)e.Item.FindControl("pnlReply");
pnlReply.Visible = true;
}
if (e.CommandName == "Send")
{
TextBox txtTextBox = (TextBox)e.Item.FindControl("txtTextBox");
//I tried this way also..
//TextBox txtTextBox = (TextBox)e.item.FindControl("pnlReady").FindControl("txtTextBox");
Label1.Text = txtTextBox.Text;
}
}
Please use IsPostBack in page load event. Without it your FillDataList(); is executing on every postback and resetting your DataList.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
FillDataList();
}
}
I have Created A Custom Control which is a DropDownList with specified Items. I designed AutoPostback and SelectedCategoryId as Properties and SelectedIndexChanged as Event for My Custom Control.
Here Is My ASCX file Behind Code:
private int _selectedCategoryId;
private bool _autoPostback = false;
public event EventHandler SelectedIndexChanged;
public void BindData()
{
//Some Code...
}
protected void Page_Load(object sender, EventArgs e)
{
BindData();
DropDownList1.AutoPostBack = this._autoPostback;
}
public int SelectedCategoryId
{
get
{
return int.Parse(this.DropDownList1.SelectedItem.Value);
}
set
{
this._selectedCategoryId = value;
}
}
public string AutoPostback
{
get
{
return this.DropDownList1.AutoPostBack.ToString();
}
set
{
this._autoPostback = Convert.ToBoolean(value);
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
if (SelectedIndexChanged != null)
SelectedIndexChanged(this, EventArgs.Empty);
}
I Want Used Update Panel to Update Textbox Fields According to dorp down list selected index.
this is my code in ASPX page:
<asp:Panel ID="PanelCategory" runat="server">
<p>
Select Product Category:
<myCtrl:CategoryDDL ID="CategoryDDL1" AutoPostback="true" OnSelectedIndexChanged="CategoryIndexChanged"
SelectedCategoryId="0" runat="server" />
</p>
<hr />
</asp:Panel>
<asp:UpdatePanel ID="UpdatePanelEdit" runat="server">
<ContentTemplate>
<%--Some TextBoxes and Other Controls--%>
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="CategoryDDL1" />
</Triggers>
</asp:UpdatePanel>
But Always The Selected Index of CategoryDDL1 is 0(Like default). this means Only Zero Value will pass to the event to update textboxes Data. what is the wrong with my code? why the selected Index not Changing? Help?
If your BindData() method is completely self-contained, move that from Page_Load to:
protected override void OnInit(EventArgs e)
{
BindData();
}
This will keep your dropdown list in your control from being rebound on every page load, which I assume is the problem from the code that you've posted.
If, however, your BindData() method requires information from the parent page, change the page load to:
protected void Page_Load(object sender, EventArgs e)
{
if(!this.Page.IsPostback) {
BindData();
}
DropDownList1.AutoPostBack = this._autoPostback;
}
This will allow your dropdown to be bound only on the first page load, and subsequent loads should be able to access the properties correctly.
Also, be sure to check your ASPX page to make sure you're not binding the ASCX control on every page load. This can be resolved in the same way on the parent page.