I am developing an asp.net web form application that displays some info on separate gridviews based on parameters. The second gridview depends of the values in the first one (Salida and Llegada, they work as a time range). This works only when the data displayed on the first GV has just one row.
This is how it works:
But, is there a way to loop the same gridviews for each row stored in the database? something like this:
Or maybe there is an easier option I haven't considered.
Thanks in advance.
Ok it should be simple, first sit your gridview1 paging to fetch only view only one record, Then after you fill your gridview1 i assume that you have putten an ID either as Datakeys or what ever method you have used, the index of the row should be 0 since it's always viewing one row only. Get your id and fetch your data and bind it the second gridview2.
After that on the Gridview1_Paging event you bind your data again and the use the same method above to fetch the data for the next record.
Seems a bit clunky, but the simplest option may be to add GV1 and GV2 to a repeater. Each row of the repeater would essentially be the data source for your GV1.
Related
I have a scenario where I want to put four identical Gridviews on the same page. (They will be on different tabs in an Ajax TabControl.) They show the same source data, but there are four corresponding groups of source data in a common underlying table. So I want to show Group 1 on Tab 1, Group 2 on Tab 2, etc. These Gridviews contain complicated controls, so I would prefer to use the same data source for all of them to avoid unnecessary repetition. The Insert and Update commands are completely identical.
So in theory I could build the Select command in such a way that I could filter the data based on the GridView that is binding to the SQLDataSource. The problem is that if I use the same SQLDataSource for all the Gridviews, I cannot find a way to have each GridView tell the SQLDataSource which one is calling it. I am thinking maybe this is not possible, because the SQLDataSource binds first before it knows what is binding to it, but I'm not sure. Can anyone think of a way to do this?
You can change the parameter value dynamically using OnSelecting event of SQLDataSource. This can be done in server side code.
Create a property which holds your current gridview unique key, which is causing SQLDataSource to fetch data from SQL database.
Assign this property unique gridview key on DataBinding event of gridview.
Based on this property change the parameter in OnSelecting event of SQLDataSource.
Let me know if I am missing something.
I have a gridview which was working fine with a small dataset in development. In production it has to bind to thousands of records, which is making it slower to load. Is there a way to improve performance, like retrieving the data during gridview pageindex changing?
Also chances are you only want to bind it once. So you should (if not already):
if(!IsPostback)
{
DatabindGridLogicHere();
}
This way your GridView will only have to hit the db the first time to get the data.
First and formost turn off ViewState.
You should tell your datasource to take less records and then enable paging in your grid and datasource.
You can enable "AllowPaging" property to true in your GridView and give a page size say 10. Then Write your data retrieval logic to return a batch of data instead of the whole set of data at once.
When you write the SQL query make sure to order it by an ID.
Thus if the page index is 1 you can take the first batch of data by passing page index of 1 and the page size of 10.
Logic will be;
SELECT [RequiredFields]
FROM [YourDataSource]
WHERE (Id>=((PageIndex-1)*pageSize) AND Id<(PageSize*pageIndex)) ORDER BY Id
In the first page it will return first set of entries of those Ids starting from 0 to 9. In the second page it returns entries of those Ids starting from 10 to 19 assuming the pageSize is 10. You can change the page size and the query logic as you wish.
But if sorting is enable then this will not produce accurate results.
How Can I find all the rows that has been changed in gridview. I can not use Ajax in any form
First get the contents of your grid before it was changed (such as caching the results of the original gridview datasource binding). Then go through the dataset/datatable/however you want to store it, and compare the contents with the current rows of the gridview.
There's no real efficient way to do this, no method like GridView.GetAllChangedRows(). So, what you might do instead is keep a behind the scenes List that you add to each time a row is modified (use the RowUpdated method), then clear this list when needed.
It depends upon how many columns you want to edit in a row.
If you have only one editable column in a row then you can associate a javascript method with that control which you want to modify and in that method you can get a rowid which you can save in another hidden field and in server side you can get all rows whose ids are stored in hidden field.
If you have whole row editable in that case the best approach I think you should save the original data source somewhere and also set a javascript method with rowclick event to get rowid which user selects. Then when user clicks on submit button get all rows whose row ids are stored in hidden field then compare those with same rowid in datasource. This is the best approach from my point of you.
Let me give you an example, suppose there are 1000 rows in a grid and user clicks on only 180 rows. In that case we will compare only 180 rows and wont compare rest of the rows.
Please let me know if somebody has better idea then this.
Is there a way with ASP.NET to tell a data repeater which is working against a objectDataSource to only show the first row and not any others that are returned in the objectDataSource.
I can't limit the data source to one row as it's echo'ing to a grid above the repeater.
Forgive me if this is a stupid question!
Thanks in advance
C
in your repeater event handler you can use the event object to see what number the item in the collection you are on.
So you can say if that number > 0 or 1 or whatever it is, render, if not, do nothing.
It's been a really long time since I've used .NET, but I know you can lookup the index of the item in the ItemDataBound event.
I know how to use the checkboxlist in ASP.NET to display options retrieved from a database. What I don't know how to do is to make this 2-dimensional. That is, I need a list of checkboxlists where I don't know how long the list is; both dimensions of the checkboxlist will be determined by
list of people (pulled from database)
list of tasks (pulled from database)
and the user of the web page will click in column/row to specify which people will be assigned which tasks.
Right now I'm thinking that my only option is to brute-force it by creating a table and populate each cell with its own checkbox. (yuck)
Is there a more elegant way to create a 2-dimensional array of checkboxes with labels for both rows and columns?
I would use a repeater along with a checkboxlist. Depending on how your database is setup you could have each checkboxlist databound.
I've done this before and resorted to the brute-force method you suggest.
It's not as nasty as you'd think. Other solutions that were declarative and databound would likely be just as convoluted and confusing.
I use the ASPxGridView from DevExpress. It has a control column type of Selected (or something like that) which will display a checkbox in the column with the other column populated from your bound datasource. The User can select any rows desired by checking the checkbox on the row and you can get all the selected rows easily inot a collection to process. DevExpress components really do get rid of a lot of brute-force programming.
You can programmitaclly use a GridView control. It's inherently two-dimensional and you can use databound CheckBoxFields for it.
If you're looking for a quick and dirty way, you can use the AJAX Control Toolkit with the two controls and can populate one based on the other. If that's not what you're looking for, I'd do it the brute force way.