I have problem with not firing selected index changed event of dropdownlist in gridview. I gone through the SO Thread . It is not worked wholly for me. I have implementation like below.
.ASPX
<asp:DropDownList ID="DDL1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DDL1_SelectedIndexChanged">
<asp:ListItem Text="Review" Value="Review" Selected="True">Review</asp:ListItem>
<asp:ListItem Text="Level1" Value="lvl1">Send Back to Level1</asp:ListItem>
</asp:DropDownList>
.CS
protected void Page_Load(object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
// Bind the GridView to something.
DataBindGrid();
}
else {
// Bind the GridView again to maintain previous entered data in the gridview
DataBindGrid();
}
}
protected void DDL1_SelectedIndexChanged(object sender, EventArgs e)
{
this.lblCity.Text = ((DropDownList)sender).SelectedValue;
}
protected void grdPoll_RowDataBound(object sender, GridViewRowEventArgs e)
{
if(Page.IsPostBack)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
DropDownList ddl = e.Row.FindControl("DDL1") as DropDownList;
if(ddl != null)
{
ddl.SelectedIndexChanged += new EventHandler(DDL1_SelectedIndexChanged);
}
}
}
}
When i keep if(!Page.IsPostBack) block only then it works fine. But i want else block also. Whats going wrong with implentation. Can you please suggest the solutions
The problem is block after !Page.IsPostBack block, which is not event else part as you said. You are binding grid again on post back which results in loss of the event being fired. You do not have to bind it again to have the changes in the grid.
Remove this code.
{
// Bind the GridView again to maintain previous entered data in the gridview
DataBindGrid();
}
Try this:
protected void Page_Load(object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
// Bind the GridView to something.
DataBindGrid();
}
else {
// Bind the GridView again to maintain previous entered data in the gridview
//DataBindGrid(); //remove DataBindGrid(); from else
}
}
protected void DDL1_SelectedIndexChanged(object sender, EventArgs e)
{
this.lblCity.Text = ((DropDownList)sender).SelectedValue;
DataBindGrid();
}
replace event name "Page_Load" with "Page_PreRender"
Related
I have a formular with dynamic data and UC.
my ascx file looks like:
<asp:Repeater ID="rMyData" runat="server" OnItemDataBound="OnRepeaterItemDataBound">
<ItemTemplate>
<asp:Panel ID="panelAdditional" runat="server"/>
</ItemTemplate>
</asp:Repeater>
and the cs file:
public partial class MyFormular
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
PrepareList();
DataBind();
}
}
private void PrepareList()
{
rMyData.DataSource = GetData();
rMyData.DataBind();
}
protected void OnRepeaterItemDataBound(object sender, RepeaterItemEventArgs e)
{
RepeaterItem repeaterItem = e.Item;
Panel panel = (Panel)repeaterItem.FindControl("panelAdditional");
if (panel != null)
{
var datarow= (Data)repeaterItem.DataItem;
if (datarow!= null)
{
panel.Controls.Clear();
MyUC ctrl;
ctrl = (MyUC)Page.LoadControl("~/MyUC.ascx");
ctrl.Enabled = true;
ctrl.DataRow = datarow;
panel.Controls.Add(ctrl);
}
}
}
protected void SaveNewsletterSubscription(object sender, EventArgs e)
{
...
}
}
My problem is, it doesn't show my UC.
If I put my PrepareList() and DataBind() outside of the PostBack, it works perfectly fine and shows my UC. But after I press the save Button, it reloads the page and rebind my repeater. So I lost everything in the UC.
Why does it only show my UC if I rebind it in every pageload?
I hope the I posted enough information.
I have a form and I am want to call a stored procedure on text change event of that text-box ,
Can you suggest any idea.
Thanks in advance.
You just have to handle the TextChanged-event:
<asp:TextBox ID="TextBox1" runat="server"
OnTextChanged="TextBox1_TextChanged">
</asp:TextBox>
Codebehind:
protected void TextBox1_TextChanged(Object sender, EventArgs e)
{
TextBox txt = (TextBox) sender;
// call your stored-procedure
}
Note that you should databind the controls only if(!IsPostBack), otherwise the events are not triggered. So for example in Page_Load:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DataBindForm(); // which sets the `Text` property of this TextBox among others
}
}
I'm trying to set an initial selection for a DropDownList by calling: drop.SelectedIndex = 5 in Page_Load.
This works, but then if I change the selection manually and want to save the form, I'm still getting the initial selection instead of the new selection when calling drop.SelectedValue. What's wrong?
You have forgotten you check if(!IsPostback). Otherwise you will select the 6th item again on postbacks before the SelectedIndexChanged event is triggered (or a button-click event):
protected void Page_Load(Object sender, EventArgs e)
{
if(!IsPostBack) // do this only on the initial load and not on postbacks
dropDwonList1.SelectedIndex = 5;
}
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//set up data here
}
}
if (Page.IsPostBack)
{
//do page reload logic in here
}
protected void foo(object sender, EventArgs e)
{
//get your selected value here
}
Try this code
You should be using if(!IsPostback) in the Page_Load function.
protected void Page_Load(Object sender, EventArgs e)
{
if(!IsPostBack)
{
drop.SelectedIndex = 5;
//yourcode
}
}
Through this your problem will be solved
I have
<asp:GridView>
<asp:TemplateField HeaderText="PsyHealth">
<ItemTemplate>
<asp:PlaceHolder runat="server" ID="PsyHealth" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="-">
<ItemTemplate>
<asp:LinkButton ID="Gen" CommandName="Gen" runat="server" Text="gen" />
</ItemTemplate>
</asp:TemplateField>
and
protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
var dataItem = e.Row.DataItem as ViewModels.UserTestorViewModel;
var psyHealth = e.Row.FindControl("PsyHealth") as PlaceHolder;
if (psyHealth != null)
{
psyHealth.Controls.Add(dataItem.PsyHeath);
}
}
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
//bla bla bla
}
but when I clicked the Gen LinkButton on the page. The GridView1_RowCreated was triggered first and threw the error Object reference not set to an instance of an object because the e.Row.DataItem was null.
Edit: The Code Behind
protected void Page_Load(object sender, EventArgs e)
{
List<ViewModels.UserTestorViewModel> utViewModelList = new List<ViewModels.UserTestorViewModel> { };
utViewModelList = utRepo.GetUserTestorViewModelListByHrId();
this.GridView1.DataSource = utViewModelList;
this.GridView1.DataBind();
if (!IsPostBack)
{
}
}
protected void Page_Init(object sender, EventArgs e)
{
GridView1.RowCreated += new GridViewRowEventHandler(GridView1_RowCreated);
}
Can you store the utViewModelList in Session first time you get it? If so then you can get the UserTestorViewModel instance from saved by the selected row's DataKey value.
When you click any button in the gridview , your page is postbacked and the page load event is called before it goes into the RowCommand event. In the page load event you are binding your gridview again and that's why your RowCreated Event is called.
You have to bind your gridview under if (!IsPostBack)
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
List<ViewModels.UserTestorViewModel> utViewModelList = new List<ViewModels.UserTestorViewModel> { };
utViewModelList = utRepo.GetUserTestorViewModelListByHrId();
this.GridView1.DataSource = utViewModelList;
this.GridView1.DataBind();
}
}
Edit: Now I got your issue after you posted code..
The problem is here in Page_Init, can you remove the event handler from here and try the following:
protected void Page_Init(object sender, EventArgs e)
{
GridView1.RowCreated += new GridViewRowEventHandler(GridView1_RowCreated);
}
add here
<asp:GridView onrowcreated="GridView1_RowCreated">
So, I have a GridView with an ObjectDataSource, and I want to programmatically set one of the SelectParameters of the ObjectDataSource.
I tried (during both Page_Load and DropdownList__SelectedIndexChanged)
objectDataSource.SelectParameters["my_parameter"].DefaultValue = "my_value";
objectDataSource.DataBind();
but it didn't work. What would you suggest?
Trap the onselecting event on the datasource.
protected void ObjectDataSource1_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
{
e.InputParameters["month"] = DateTime.Now.Month;
}
Nevermind, I solved it myself.
In Page_Load:
objectDataSource.Selecting += new ObjectDataSourceSelectingEventHandler(objectDataSource_Selecting);
Then write the handler method:
void objectDataSource_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
{
int four = 2 + 2;
e.InputParameters["my_parameter"] = four;
}
Then make sure to databind the GridView somewhere
protected void dropDownList_SelectedIndexChanged(object sender, EventArgs e)
{
gridView.DataBind();
}