I searched SO, google & Telerik forums, but could not find a solution.
I have an existing app (written by a previous developer) that is calling a stored procedure that populates a RadGrid control. It populates fine the first time around.
However, when I change the date parameter, click "search" button, I get a blank RadGrid control. When I click search the second time, the grid is populated. When I walk through the code, I get an error message
Column 'ID' does not belong to table Table.
How can I resolve the issue of having to click search twice to display data ?
My code behind is:
protected void btnSubmit_OnClick(object sender, EventArgs e)
{
try
{
ViewState["newset"] = null;
CreateDatasource();
this.RadGrid1.DataBind();
this.RadGrid1.CurrentPageIndex = 0;
ViewState["newset"] = "new";
string idex = this.hdnindex.Value;
if (idex != string.Empty)
this.RadGrid1.MasterTableView.Items[int.Parse(idex)].Selected = true;
}
catch (Exception ex) {
this.lblMessage.Text = ex.Message;
}
}
protected void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
{
try
{
if (e.Item is GridDataItem)
{
GridDataItem item = (GridDataItem)e.Item;
HyperLink hLink = (HyperLink)item["ViewHyperLink"].Controls[0];
if (hLink != null)
hLink.Attributes.Add("onclick", "selectMe('" + item.ItemIndex + "');");
}
}
catch (Exception ex)
{
this.lblMessage.Text = ex.Message;
}
}
In the code behind above, when this.RadGrid1.DataBind() is called, the code steps into RadGrid1_ItemCreated loops through the if statement a few times, them goes into the if statement, comes out of the function, and then the catch statement of btnSubmit is called, which displays the error message "Column ID does not belong to table Table".
Any ideas on how to resolve this?
Maybe you should try Grid - Simple Data Binding. Also you this thread (RadGrid NeedDataSource Page load) on telerik forum talks in detail about Simple Data binding. I don't know if you are trying to use NeedDataSource, but I have had similar issues before and the Simple Data binding worked perfectly.
That sure sounds like to me you need to call RadGrid1.Rebind() somewhere. Try calling that for your last line in your try block inside btnSubmit_OnClick.
Also, what does this search button do? Does it filter the results based on a date?
Related
Object reference not set to an instance of an object.
protected void cmdSave_Click(object sender, EventArgs e)
{
string strNames = string.Empty;
CheckBoxList Chkboxx = (CheckBoxList)PlaceHolder1.FindControl("Chkbox");
foreach (ListItem em in Chkboxx.Items) //-------- (Showing error)
{
if (em.Selected)
{
strNames += em.Value + ", ";
}
}
string final_name = strNames.Substring(0, strNames.Length - 2);
lblNames.Text = final_name;
}
Actually I am adding Checkbox control dynamically :
protected void ddl_varient_SelectedIndexChanged1(object sender, EventArgs e)
{
string query = "select prd_vrtyvalue_id,varient_value from tbl_ProductVariety_Value where varient='" + ddl_varient.SelectedItem.Text + "' " +
" order by varient_value asc ";
DataTable abc = new DataTable();
SqlDataAdapter ada = new SqlDataAdapter(query, new CommonClass().connection());
ada.Fill(abc);
ChkboxList.ID = "Chkbox";
for (int i = 0; i < abc.Rows.Count; i++)
{
ChkboxList.Items.Add(new ListItem(abc.Rows[i]["varient_value"].ToString(), abc.Rows[i]["prd_vrtyvalue_id"].ToString()));
}
ChkboxList.RepeatColumns = 2;
PlaceHolder1.Controls.Add(ChkboxList);
}
Can Anybody tell me, what exactly i am doing wrong !
The way ASP.NET WebForms work is that the entire page is re-built during each post back. So, I imagine this is what is occuring:
Page gets "built" and includes only controls defined within your ASCX/ASPX file.
User clicks on DDL_VARIENT checkbox and the ChkboxList is added to PlaceHolder1
Form is rendered back to the user so they can see ChkboxList
Save button is clicked, causing another postback.
Page is re-built, setting all the controls back to what is defined within your ASPX/ASCX code. This does not include ChkboxList.
Your code is hit, ChkboxList no longer exists and you get your problem.
To fix, you could re-add your ChkboxList on Page_Load depending on the value of your DDL_VARIENT checkbox. If I were you though, I'd be tempted to define the ChkboxList within your ASPX/ASCX code and then set the visibility of the list depending on the value of the DDL_VARIENT checkbox within Page_Load.
I should add, the entire of the above is dependant upon you using ASP.NET WebForms. If you're using MVC then it's probably wrong.
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.sorting.aspx
This article deals with creating a datatable first, then creating a gridview from it, to aid in sorting. My predicament is slightly different.
I have a Gridview, that on Page_Load, I set the datasource to an ArrayList, and bind.
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
this.GridView1.DataSource = RequestManager.Instance.GetAllRequests();
this.GridView1.DataBind();
}
}
Now I would like to sort this GridView, so on the aspx page, I set AllowSorting="true", and OnSorting="GridView1_Sorting". So far, so good. I have the SortExpressions set in the BoundFields, and when I click on it, I know the _Sorting event is triggered.
Now, since this is a postback operation, I cannot simply cast the datasource of the gridview to a DataTable to sort. Saving to ViewState is an option, but I cannot figure out how to do it.
I would like to use the simple solution on this page, except for the DataTable not being available to me. Thanks for looking.
If you're able to target .NET v3.5, I recommend using Linq. In your _Sorting event handler, get the array list you did in the Page_Load and rebind it.
For example, if the type contained in the array list are MyType instances that have properties named Default and SomeField:
protected void Grid_Sorting(object sender, GridViewSortEventArgs e)
{
Func<MyType, object> keySelector;
if(e.SortExpresion == "SomeField")
{
keySelector = dataItem => dataItem.SomeField;
}
else
{
keySelector = dataItem => dataItem.Default;
}
ArrayList dataItems = RequestManager.Instance.GetAllRequests();
this.GridView1.DataSource = dataItems.OfType<MyType>().OrderBy(keySelector);
this.GridView1.DataBind();
}
That will get you started, then later inspect the sort expression to see if it ends with ASC or DESC and conditionally call .OrderByDescending(keySelector).
Finally, I don't recommend stashing the list in ViewState, as the ObjectStateFormatter is only optimized for a handful of types. http://msdn.microsoft.com/en-us/library/system.web.ui.objectstateformatter.aspx
Maybe consider ASP.NET cache instead.
I implemented sorting on my GridView with a DataTable as DataSource by using code from this MSDN link. However, my grid sorts for the first time when I click any column, and after that it does not sort on clicking any other column.
Code in the PageLoad() event -
if (!Page.IsPostBack)
{
HView hv = new HView ();
DataTable HTable = new DataTable("hTable");
HTable = hv.FillTable();
Session["hTable"] = HTable;
GridView2.DataSource = Session["hTable"];
GridView2.DataBind();
}
Code in the Sorting event -
protected void GridView2_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable notesDT = Session["hTable"] as DataTable;
if (notesDT != null)
{
notesDT.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortDirection);
GridView2.DataSource = Session["hTable"];
GridView2.DataBind();
}
}
Does anybody have an idea of what I may be doing wrong?
EDIT: I just realized this. If I select a particular row, I have another view that gets populated with details about that row. When I view some rows details first before trying to sort any columns, then sorting works perfectly fine, any number of times. However, if I try to sort before selecting a row, it works only once.
You are using the DataTable as DataSource in the sorting event, but you should use the sorted view instead. Sorting the view won't change the sort order of the data in the table, just the order in the view.
protected void GridView2_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable notesDT = Session["hTable"] as DataTable;
if (notesDT != null)
{
notesDT.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortDirection);
GridView2.DataSource = notesDT.DefaultView;
GridView2.DataBind();
}
}
Edit: Although that i've just noticed that you're using rhe same code from MSDN.
You could also try to create a new DataTable from the view:
GridView2.DataSource = notesDT.DefaultView.ToTable(true);
You don't need stored the data table into a session. Actually putting the entire data table into session is not a good idea at all. Any particular reason for that?
I have a GridView that gets it's data from the SQL database.
I would like to alter some of it using an external method, something like this:
SQL in:
ID:0
Then, the altered method will be called with 0 as a parameter, and will return some string that will be shows in the GridView.
Thank you, Mark.
Attach a handler to the RowDataBound event. You have full control to all of the cells in the GridViewRow, and can modify the text anyway you want. Example from MSDN:
void CustomersGridView_RowDataBound(Object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
// Display the company name in italics.
e.Row.Cells[1].Text = "<i>" + e.Row.Cells[1].Text + "</i>";
}
}
Reference at: http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.rowdatabound.aspx
I have used the following code to add the feedback entered to the web form into a database.
The code works fine. But when I try to deleted thi statement
SqlCommandBuilder objcb = new SqlCommandBuilder(objDa);
I am getting an error I mean it is executing the else part.
Can any one tell me what is the use of SqlCommandBuilder?
protected void btnSubmit_Click(object sender, EventArgs e)
{
if (txtName.Text.Trim() == "")
{
Response.Write("<script>alert ('Name Field cannot be left blank')</script>");
return;
}
if (txtFeedBack.Text.Trim() == "")
{
Response.Write("<script>alert('FeedBack Field cannot be left blank')</script>");
return;
}
objSqlConnection.ConnectionString = connectionStringSetting;
objSqlConnection.Open();
try
{
SqlDataAdapter objDa = new SqlDataAdapter("select * from FeedBack", objSqlConnection);
SqlCommandBuilder objcb = new SqlCommandBuilder(objDa);
DataSet objDs = new DataSet("FeedBack");
objDa.Fill(objDs, "FeedBack");
DataRow dr = objDs.Tables["FeedBack"].NewRow();
dr[1] = txtName.Text;
dr[2] = txtAddress.Text;
dr[3] = txtCity.Text;
dr[4] = txtCountry.Text;
dr[5] = txtEmail.Text;
dr[6] = Convert.ToInt32(txtContactNo.Text);
dr[7] = txtFeedBack.Text;
objDs.Tables["FeedBack"].Rows.Add(dr);
objDa.Update(objDs, "FeedBack");
Response.Write("<script>alert('Your FeedBack has been submitted')</script>");
objSqlConnection.Close();
}
catch (Exception)
{
Response.Write("<script> alert('Error on Page. Please try after sometime')</script>");
objSqlConnection.Close();
}
And is there any way to display the specific error messages like if an user enters a string value instead of Integer value it should display the message as 'Input String not entered in correct format?
Never use catch (Exception). It hides the problem. If an exception is being thrown, then there's something serious wrong. You need to learn about it.
Remove the entire try/catch block (keep the code inside it!). Then run your code again. If there's an exception, then you'll see it on the error page. If not, then use the Event Viewer to look in the Windows Event Log for a warning message from the "ASP.NET" source. It should contain the complete exception.
Final answer is that the line you are talking out is doing a bunch of stuff in the background.
It is adding the insert, update and delete commands to the DataAdapter. So without it, you will crash and burn, unless you add those commands yourself to the DataAdapter.