I have created a GridView whose columns are dynamically created based on my data source. I have implemented these columns by using the approach described here.Those columns display properly on the initial load. However, I need to implement commanding so that a user can edit / delete a row in the GridView.
At this point, I have implemented commanding as I would with a normal GridView. I have a TemplateField with an ItemTemplate that has LinkButton elements for edit and delete. The CommandName for each LinkButton is set to either Edit or Delete respectively.
Oddly, when a user clicks either the Edit or Delete link, the data in the GridView disappears. However, I have verified that I am in fact re-binding the data when one of these LinkButton elements is selected.
Can anyone provide some suggestions as to what the cause could be?
Thank you!
Here are good examples. You can figure out postback issue.
http://quickstarts.asp.net/QuickStartV20/aspnet/
Related
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.
I have a gridview full of telephone numbers. To populate the gridview I bind the gridview's datasource to a List<> of telephone numbers. I do this when the page is first loaded, but not on postbacks.
I want the user to be able to delete some of the telephone numbers, and then, if they want, click a Save button, and this will update the database, otherwise their changes will be ignored. So I have a button in the grid, and an event is fired, and I can call DeleteRow(row index) and remove the row from inside this event. For some reason this doesn't work.
All the gridview examples I find on the Internet execute the delete straight away by calling an sql function, and then bind again. And some examples bind the grid every time the page ios loaded, which seems inefficient.
My questions is:
The delete button causes a postback to the server. On postback the list of telephone numbers no longer exists. And the gridview's datasource is null. The grid is no longer bound. But there must be data somewhere, because the data in the grid is still visiable. Where is this data, and can I delete a row of it, so that a row in the gridview is deleted?
The viewstate saves the contents of the datagrid, so the answer is "The Viewstate"
Understanding the viewstate is essential to understanding how ASP.NET works, so rather than posting just enough info to answer your question, I'm going to recommend you read the entire article I linked to.
You can use jquery , you need to save the Datakey value of each deleted row in a hidden field
and hide the selected row , and when user clicks save , u can delete the rows based on hidden field values # code behind.
Ok, i have a gridview and on page load, i dynamically add a column to it that contains a link control. this link control has a onclick event associated with it so that when its clicked, i want to do some processing. Now I have noticed that if I just bind the grid the first time (i.e. if(!IsPostBack) and have enableviewstate for the grid to be true, clicking the link in that column, doesnt trigger the onclick event. But if I bind the grid on every postback, everything seems to be working..does anyone know the reasoning behind it?
It happens because you're dynamically adding the column, so on every postback the column has to be created. What you may want to do is to look at Creating a Custom Column.
May be creating the row Id solves your problem. Check out this link and the post marked as answer.
http://forums.asp.net/p/1471128/3408069.aspx#3408069
Regards
Vinay
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.
Currently I am highlighting the rows on my gridview through code behind. The problem is when I inserted a new data through formview, I put the highlight on the new data but if you click edit or delete if would go for either the first data on the grid if you have not selected anything yet or the last data you have selected. Thanks.
According to the MSDN Documentation, GridView.SelectedDataKey its a read only property.
You may want to check the documentation for GridView.SelectedPersistedKey which is settable.