Session value and pagable datagrid

[shahab]

Dear Friends,

I am using a pagable datagrid and a session like this:

 

Session["NewsId"]=DataGrid1.DataKeys[(int)e.Item.ItemIndex];

 

When I browsing through the pages of datagrid this error is shown to me:

Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

 

Exception Details: System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

 

Source Error:

 

Line 179: {

Line 180: //Label3.Text=DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();

Line 181: Session["NewsId"]=DataGrid1.DataKeys[(int)e.Item.ItemIndex];

 

What should I do in order to solve this problem?

[kahlua001]

Can you post more code. Perhaps the entire sub.

[Robby]

shahab, does this occur soon after you alter the record count of the datatable.

[shahab]

private void DataGrid1_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)

{

//Label3.Text=DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();

Session["NewsId"]=DataGrid1.DataKeys[(int)e.Item.ItemIndex];

/**/

if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "edit")

{

Response.Redirect("EditNews.aspx");

}

if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "first")

{

SetInDefaultWebForm();

Response.Redirect("../Default.aspx");

}

if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "del")

{

DelNews();

//Response.Redirect("DelNews.aspx");

}

if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "DelF")

{

RemoveFromDefaultWebForm();

Response.Redirect("../Default.aspx");

}

if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "َAdd")

{

Response.Redirect("AddNews.aspx");

}

}

//**********************************************************

 

 

private void DataGrid1_PageIndexChanged(object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)

{

DataGrid1.CurrentPageIndex=e.NewPageIndex;

}

[shahab]

This occured when I make my DataGrid Pagable!

At the First it wasn't!

[Robby]

Check the value of e.NewPageIndex before setting it to the current page

[shahab]

How can i set it?

[Robby]

e.NewPageIndex is read-only, I ment verify its' value prior to assigning it to the CurrenPageIndex of the Datagrid

[shahab]

1-In page load u mean?Where?

2-How can I verify it?Code Please :)

[Robby]

You can do it in the PageIndexChanged event or anywhere else that you assign a value to the CurrentPageIndex property.

 

Compare the DataGrid1.PageCount to the e.NewPageIndex and don't allow less than 0

[shahab]

:rolleyes: Edited March 20, 2004 by shahab

[PlausiblyDamp]

shouldn't (DataGrid1.PageCount - e.NewPageIndex) <= 0 be (DataGrid1.PageCount - e.NewPageIndex) > 0

[shahab]

Oh I'm sorry but now I have another problem with this code:

New Code:

private void DataGrid1_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
       {
           //DataGrid1.DataKeys[(int)e.Item.ItemIndex]=-1;
           //Label3.Text=DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();
           //Session["NewsId"]=DataGrid1.DataKeys[(int)e.Item.ItemIndex];
           //DataGrid1.SelectedItem.ItemIndex.ToString();Wrong
           if ((DataGrid1.PageCount - e.NewPageIndex) > 0)
           {
               DataGrid1.CurrentPageIndex=e.NewPageIndex;
               //Session["NewsId"]=DataGrid1.DataKeys[0];
               bindGrid1();
           }    
           /**/
               if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "edit")
               {
                   Response.Redirect("EditNews.aspx");
               }
               if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "first")
               {
                   SetInDefaultWebForm();                
                   Response.Redirect("../Default.aspx");
               }
               if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "del")
               {
                   DelNews();
                   //Response.Redirect("DelNews.aspx");
               }
               if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "DelF")
               {
                   RemoveFromDefaultWebForm();
                   Response.Redirect("../Default.aspx");
               }
               if (((DropDownList)e.Item.FindControl("DropDownList1")).SelectedValue == "َAdd")
               {                
                   Response.Redirect("AddNews.aspx");
               }                            
       }

       private void DataGrid1_PageIndexChanged(object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)
       {
           try
           {
               if ((DataGrid1.PageCount - e.NewPageIndex) > 0)
               {
                   DataGrid1.CurrentPageIndex=e.NewPageIndex;
                   //Session["NewsId"]=DataGrid1.DataKeys[0];
                   bindGrid1();
               }
           }
           catch (Exception e01)
           {
               Label3.Text = e01.Message.ToString();
           }
       }
   }

Error message :

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

 

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

 

Source Error:

 

 
Line 169:            //Session["NewsId"]=DataGrid1.DataKeys[(int)e.Item.ItemIndex];
Line 170:            //DataGrid1.SelectedItem.ItemIndex.ToString();Wrong
Line 171:            if ((DataGrid1.PageCount - e.NewPageIndex) > 0)
Line 172:            {
Line 173:                DataGrid1.CurrentPageIndex=e.NewPageIndex;

D:\Inetpub\wwwroot\School\AdminNews\ChooseNews.aspx.cs(171): 'System.Web.UI.WebControls.DataGridCommandEventArgs' does not contain a definition for 'NewPageIndex'

:confused: :confused: :confused:

Edited March 20, 2004 by Robby