I have an asp.net C# web app. In it I have a gridview. The gridview gets search results from a database. Sometimes there are a lot of results, and so I wanted to use paging. Here's what I tried:
protected void grdResults_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
grdResults.PageIndex = e.NewPageIndex;
grdResults.DataBind();
}
For some reason, when I click on a page number, it shows me the EmptyDataText(There are no records to display). What code would work?
Please help.
Thank you
Try assigning the datasource in NeedDataSource event.
Cheers.
You need to reassign your datasource to grdResults before the call to DataBind().
Try this code It will absoloutly work :
protected void GV_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GV.PageIndex = e.NewPageIndex;
BindGrid();
}
public override void BindGrid()
{
query = new CommonQueries();
GV.DataSource = query.getAllBooks();
GV.DataBind();
}
the problem with your code is that you did'nt reassign the data source to your gridview !
Related
I have a panel ViewStock where i am viewing stock in a gridview from database and DataBind() it via code. Allowed paging and created and event "OnPageIndexChanging" in gridview tag in html, Implemented the defined code above and paging in an event as follows:
HTML:
<asp:Panel ID="Panel_StockView" runat="server">
<asp:GridView ID="GridView_Stock" AllowPaging="true" OnPageIndexChanging="GridView_PageIndexChanging" runat="server"></asp:GridView>
</asp:Panel>
Code C#:
protected void LinkButton_Panel_ViewStock_Click(object sender, EventArgs e)
{
using(SqlConnection con = new SqlConnection(cs))
{
//Sql command here
/sql adapter and filled datatable
sdaStockView.Fill(dtStockView);
GridView_Stock.DataSource = dtStockView;
GridView_Stock.DataBind();
}
}
And now the Implemented Paging
protected void GridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView_Stock.DataBind();
GridView_Stock.PageIndex = e.NewPageIndex;
}
it does work but partially. It does the paging and does the data correctly. But, the issue is when i click the page '2' the panel blanks out just like in the picture i uploaded See this Image, then i click the link button that redirects me to the panel again and opens the page '2' of the gridview with valid data.
How to resolve this issue?
Extract the logic which binds the GridView to data into a new method.You can call it BindData() for example:
private void BindData()
{
using (SqlConnection con = new SqlConnection(cs))
{
sdastockview.fill(dtstockview);
gridview_stock.datasource = dtstockview;
gridview_stock.databind();
}
}
Call this method inside LinkButton_Panel_ViewStock_Click to populate the GridView:
protected void LinkButton_Panel_ViewStock_Click(object sender, EventArgs e)
{
this.BindData();
}
Lastly, call it again to re-populate the GridView during paging:
protected void GridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView_Stock.PageIndex = e.NewPageIndex;
this.BindData();
}
Just make those three little changes and it will work. I've tried this on my side and it's working just fine.
Save your DataSet somewhere like ViewState on LinkButton_Panel_ViewStock_Click after filling DataSet like this
ViewState["ds"] = dtStockView
In PageIndexChanging write like this
protected void GridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
panel_ViewStock.visible = true;
GridView_Stock.PageIndex = e.NewPageIndex;
GridView_Stock.DataSource = ViewState["ds"] as DataSet
GridView_Stock.DataBind();
}
Hope this will help you
You can try to use:
protected void GridView_RowCommand(object sender, GridViewCommandEventArgs e)
I am searching for some data from a database into a datagrid. When I applied paging on it, on clicking the next link of paging the datagrid vanishes without showing anything. I used datagrid.databind() in pageload too when it's postback or I even made a postback event method named datagridname_onpageindexchanged() as :
protected void DataGridSearchResults_PageIndexChanged(object source, DataGridPageChangedEventArgs e)
{
DataGridSearchResults.currentpageindex=e.newpageindex;
DataGridSearchResults.databind();
}
Your aspx should include Paging :-
<asp:DataGrid ID="DataGridSearchResults" runat="server" AllowPaging="true" PageSize="10"
OnPageIndexChanged="DataGridSearchResults_PageIndexChanged">
If grid is having data at pageload, it should bind like this :-
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//Bind your grid here.
}
}
Then the page index changed function :-
protected void DataGridSearchResults_PageIndexChanged(object source, DataGridPageChangedEventArgs e)
{
DataGridSearchResults.CurrentPageIndex = e.NewPageIndex;
//Bind your Grid here again.
}
If(! IsPostBack)
{
// Bind your dataGrid
}
see this link http://msdn.microsoft.com/enus/library/system.web.ui.webcontrols.datagrid.allowcustompaging.aspx
You need to set DataSource here for your datagrid.
protected void DataGridSearchResults_PageIndexChanged(object source, DataGridPageChangedEventArgs e)
{
DataGridSearchResults.CurrentPageIndex = e.NewPageIndex;
DataGridSearchResults.DataSource = YourDataSource;
DataGridSearchResults.DataBind();
}
Also ,If you are binding your grid in Page_Load, Make sure you are not binding your grid outside of if(!IsPostBack){}. Otherwise you will loose data on each postback.
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
//Bind Your Grid Here
}
}
i have a gridview with paging featuer,when i want to search item in DB and result displayed in gridview with paging
but when i jump another page gridview will Bind and list all items in DB with all pages,how can i solve this problem?
thanks in your advise
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGridView();
}
}
private void BindGridView()
{
using (NoavaranModel.NoavaranEntities1 dbContext = new NoavaranModel.NoavaranEntities1())
{
var query = from list in dbContext.Students
select list;
lblStudentsCount.Text = query.Count().ToString();
GridView1.DataSource = query;
GridView1.DataBind();
}
}
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
BindGridView();
GridView1.DataBind();
}
If I'm understanding correctly, you're calling GridView1.DataBind() at the end of your BindGridView() method, so I don't believe you need to do it again after your call for BindGridView(); in the PageIndexChanging event:
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
BindGridView();
}
If this didn't solve it, please let me know what happens in the comments and I'll take another look at it.
Also, if you're saying that your GridView is filling up with all items from the database (when you're expecting only certain items), that indicates a problem with your query. I would try setting a breakpoint and step through the query to see what is coming back, just to make sure you're getting back your expected results.
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
GridView1.DataBind();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
GridView1.DataBind();
}
Row editing and Row canceling editing working fine; but when I press update after changing the value in textbox, it show the old value not that value that I have change.The following is Row updating event code.
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
dao.AridNumber = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text;
dao.FirstName = ((TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]).Text;
dao.LastName = ((TextBox)GridView1.Rows[e.RowIndex].Cells[4].Controls[0]).Text;
}
update me!
I think you need to bind the data again at the last of the method inorder to show you the appropriate result.
Hope this Helps!!
Check your markup that you're using Bind() as opposed to Eva() to bind the value to the TextBox.
Here is an example:
<EditItemTemplate>
<asp:TextBox ID="someId" runat="server" Text='<%# Bind("SomeField") %>'></asp:TextBox>
</EditItemTemplate>
I have recently came across the same problem you have faced , when i tried to update the value in grid. I have called the Gridbind in Pageload that's the cause of the issue.
Are you using any function to bind the gridview or something like that?
and if you are using that function in page_load event then you wont get the updated value cause on postback it rebinds ur gridview and you will lose ur updated value.
You need to call GridView1.DataBind() in the end:
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
dao.AridNumber = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text;
dao.FirstName = ((TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]).Text;
dao.LastName = ((TextBox)GridView1.Rows[e.RowIndex].Cells[4].Controls[0]).Text;
GridView1.DataBind();
}
Edit:
You might want to check out the RowUpdating documentation, especially I think that OldValues and NewValues properties might be of use to you.
I had gridview which retrieve Products from database by sqldatasource1 ,and my manager asked me to filter this gridview by DDL to filter gridview with specfic Model ,I add some function on gridview as edit,paging .I did my code well and gridview filtred by the Model_Id which come from DDL .But when I tried to edit any product or navigate through paging I faced this error (The GridView 'GridView1' fired event PageIndexChanging which wasn't handled. )when paging ,And this for editing (The GridView 'GridView1' fired event RowEditing which wasn't handled.)
So please any one help me.
(CS)
protected void Page_Load(object sender, EventArgs e)
{
BindGridFunction();
}
private void BindGridFunction()
{
if (DDLModel.SelectedIndex < 0)
{
GridView1.DataSource = SDSModel;
GridView1.DataBind();
}
else
{
GridView1.DataSource = SDSModel2;
GridView1.DataBind();
}
}
You need to explicitly handle PageIndexChanging() and RowEditing() event through code behind.
like
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
GridView1.DataBind();
}
public void GridView1_RowEditing(Object sender, GridViewEditEventArgs e)
{
//do your code here
}