Displaying a gridview's footer with an empty (linqdatasource) datasource - asp.net

The datasource of the datagrid is a LINQDataSource which relies on the value of a dropdownlist. In addition, I want to use the footer to insert new records - so I'd prefer not to use the empty dataset template. I am trying to find a way to always display the footer regardless if the datasource is empty or not.
EDIT:
Is there a way to create an empty/invisible object of the type in the LinqDataSource?

check the following article:
http://weblogs.asp.net/joewrobel/archive/2008/01/30/a-more-elegant-solution-to-display-gridview-header-and-footer-when-the-data-source-is-empty.aspx

Related

asp.net change cell value on gridview with code behind

I have an asp.net gridview with several rows/pages.
There are some fields below it which display full details of the row which has been clicked on gridview.
I then change a field value on the details below area and the new data is saved programmatically to database.
However the value on the gridview just changed below, doesn't change.
I would like to just change de cell value on the gridview programmatically so there is no need to reload the data grid.
I am basically looking for something like:
GridView1Row.row(currentrow).column(5)="xxxx"
I've search around and found some solutions based on _onrowdatabound but this is not correct, as I just want to change one cell of the grid.
Any ideas ?
The easiest way would be to change the value in your datasource and then binding the datasource to the grid again. (don't reload it from the database just change the value in the datasource)

New row in ASP.NET GridView Control

I want to do something really simple, I just can't seem to find the EnableClientAddRow property, so I can set it to true. I have a standard GridView control on a web form. I want a button to appear on the web form. When the user clicks the button, an empty row is added to the GridView UI, so the user can enter data in the appropriate fields. The row will of course, have a "Save" button of some type in one of the columns.
I know this functionality must be in the GridView somewhere, I just can't find it. I did find some odd hacks that try to manually implement this. I'm not really interested in footer manipulations or binding tricks, just the standard add row method.
EDIT:
It appears the GridView does not support adding a row as a first-order operation. This appears to be a serious design flaw.
I typically add a new record to the underlying data source as a part of the "add record" button click action. I then re-bind the view in order to show the blank row.
The new record is typically a DataRow if the GridView is bound to a DataTable, or an object if the GridView is bound to a collection of a particular type. Not sure if that is what you consider a binding trick from your question, but it works well and is quite easy to implement.
Edit - more detail to describe the process:
Add the row to the data source, set the EditItemIndex to the newly added row in order for the row to enter edit mode, then bind the data source to the GridView. Your EditItemTemplate would contain a Cancel and a Save button. Cancel would re-bind the GridView to the underlying data source without the empty row and set EditItemIndex to -1, thereby removing the row from the GridView.
How to easily insert row in GridView with SqlDataSource
If you add a new row to the datasource, even if the row has empty values, and you databind the datasource to the Gridview, it should show up as an editable row just like any of the other rows.

How to add a FooterRow to a Gridview which has no value initially

I have a Gridview in which no rows populated initially. means i am not setting any datasource to gridview.I have to populate gridview by adding footerrow.I have given visibility of footerrow as true.So one error is coming as 'Object not set to an instance of an object'.what may be the reason for this? Can anybody help?
Actually i need to add data into the Gridview through the FooterRow.After inserting a few records,i need to insert this data into the database.So, i want this Gridview only to insert data into the database.For a particular "FileID", i have many records,thats why i am using Gridview.Is there any other method for this?
See this question: How to insert a Row in GridView.
The object reference error is probably because you have set no datasource for the GridView. In such cases, the Gridview will not render.
Edit:
I have already linked to another question which provides a very useful link to accomplish the type of functionality you desire. Since you appear not to have found it, here is the relevant link - How to easily insert row in GridView with SqlDataSource?
The article shows how you can use the EmptyDataTemplate of the GridView to enable record insertion using a GridView. Note that you will have to modify the logic a little to insert a group of records in one go, rather than one at a time.
If you have a problem with this solution, please clarify via comments.

ASP.NET GridView problem

Well i have a gridview where i have defined the columns on my own and turned autogenerating off but now i have the problem that i cant access GridView.SelectedRow.DataItem.
As it turns out to be null now, when it had a value when auto generation was turned on..
Edit:
What i need is a way to save the ID of the row while not showing the ID to the user so if there is any way to do this?
I'm guessing DataItem is only properly filled when you are using DataBinding.
Are you using DataBinding?
Ok from this url:
The GridView (and actually, all our
data controls) does not save data
items across postbacks. This reduces
ViewState (if the objects are even
serializable) and enables garbage
collection to happen and clean up your
objects. So, when you click the
button to post back, the GridView has
not called DataBind and therefore your
data item isn't there. This is what
you've discovered.
Guessing you're reading the value from a postback, might just be the problem.
Try using SelectedValue, if you've setup the (primary) key for the items.
I've always used that and it worked.
msdn about SelectedValue
You can create a new hidden template column that will have a label with the ID . and in the cs file you use .FindControl on the rows.
You also have DataKeys property on the gridview, witch I think also does what you want

ASP.NET - ObjectDataSource: using multi-select ListBox as ControlParameter

I have a form that contains a GridView control which is databound to an ObjectDataSource Control. There are several TextBox controls that are already being used as ControlParameters for the ObjectDataSource. I also have a custom data object that the ObjectDataSource is associated with {TypeName="myDataClass"}. The values are passed from the ObjectDataSource to myDataClass.
Now I need to also use a multi-select ListBox as a ControlParameter. When I use the SelectedValue parameter of the ListBox, the ObjectDataSource is only seeing the first selected item in the list.
Here's the question: How can I get all the multi-select ListBox values passed into my custom object "myDataClass" instead of just the first one selected? Hence the ["multi-select"]
Thanks for any help!
Multi-select list boxes are tricky. You need to loop through the items in code to build a list of selected values. So you will probably need to implement a custom parameter that does this for you.
You might end up needing to bind to the grid from code-behind, instead of doing it declaratively.
This is typical problem. multi-select list box always return the first selected value and not all the selected value. We have to loop through the entire collection and check each individual value if selected or not.

Resources