First, I did try to manually set readonly to false.
My code is company code so I can't share it here. I'll do my best to explain.
In a Webforms projects my .aspx page has a GridView with all the columns listed that I want to display. Additionally it has edit, delete, and update buttons for each row. Three columns are dates, and the data conversion from Oracle to asp ends up making the dates appear as "MM/DD/YYYY 12:00:00am". To strip off the timestamp, I put e.Row.Cells[x].Text = e.Row.Cells[x].Text.Split(' ')[0]; in the GridView's OnRowDataBound event.
It worked beautifully, I thought, until I started testing the edit buttons again. All three rows that have dates and the event above are now a blank white space when I put the row into edit mode. If I comment those three lines in OnRowDataBound out, the timestamps reappear and the rows are editable.
First and foremost, I need to make it work. Secondly, I'd love to know what is actually happening in the background. I'm pretty new to web dev as a whole and new to asp.net for sure.
If you create your columns in markup (AutoCreateColumns being turned off), you can use DataFormatString to format the date columns instead of modifying the cell text in code:
<asp:BoundField DataField="Date1" DataFormatString="{0:d}" ApplyFormatInEditMode="true" ... />
The format string (d in my example) can be modified to better match your preferences. And if the date columns are editable, you can also set ApplyFormatInEditMode as shown above.
Related
Goal
What I need is to display a SQL DataTable to the user on a webpage through ASP.NET and allow them to select a number of rows very quickly and easily, and then hit any of a number of different buttons to signify different operations. The selected rows are to be sent off to be processed (generally sent to a webservice or similar through codebehind). This is a somewhat generic solution, as I will be using this same setup in many places - thus the data, and the available operations will be different.
The goal is to be able to know basically nothing about the data - that is for the user to understand. If this concept is already impossible (though I believe it is not), please let me know.
Pulling from T-SQL (SQL Server 2008 R2 or later).
Using ASP.NET to make aspx webpage. Codebehind is done in VB.NET, in both cases we're using 4.0
I'm fluent in C# and VC++, so if you can't easily translate your code, don't worry about that.
The problem
My problem has been creating a row selection process for the user which persists while sorting or paging the table, is quick for the user and relatively quick in response time, and which is reflected in the GridView's bound data (as this allows me to use a filter on a DataView to produce a DataTable for passing). If there's another way to know the selected rows then I'm all game so long as it is persistant and quick for the user.
I'm not debugging and I'm not having syntax issues (I do not believe) - I don't know how to proceed.
I don't necessarily need code as a solution - I need to understand if my metaphor is either bad practice, or simply uncommon and thus not well supported. In either case, what is an appropriate way to proceed? If nothing else, where do I look for a solution besides endless API and Tutorials?
My original plan
I wanted to use asp:GridView for binding the DataTable pulled from TSQL since I can auto-generate columns. This allows me to display data without needing to know what it is. I planned to add a specific boolean Column (left most) for storing the User's row selection. Then I can simply run a filter on the DataTable to produce a DataView, get the resulting DataTable from that DataView, and pass it down the chain.
All the columns except our specific selection one would be Read-Only. The user isn't editing data - their selecting records and view their selection side-by-side with the viewable relevant data.
Of note, I planned to check for name collision so our added Column doesn't collide with any existing Column in the DataTable - I'd rename it as needed using 'Select' followed by an integer produced by looping through, comparing my name to other columns, incrementing as needed.
I presumed that once I set this up, it would just handle itself: the user could click the resulting checkbox column cell's and it would change the data on the fly. The point of saving the selection was their selection persisted through sorting and paging for convenience (I save the GridView's DataSource and re-bind when necessary). It didn't really matter if the user refreshed the page and completely and lost their checkboxes - they would need to review any changes/new data, and they wouldn't need more then a brief moment to check off whatever they wanted.
This did not happen.
I found that AutoGenerateColumns does not produce checkboxes for boolean DataColumns. It produces text, so I end up with the word 'True' or 'False'.
I began looking for a way to get check boxes in the cells for a boolean DataColumn. I found that for the added boolean column, I could bind an asp:CheckBoxField to it using the attribute DataField. Of course, I have to figure out how to point it at a variable DataField...
<Columns>
<asp:CheckBoxField DataField="Select" HeaderText="Select"
ReadOnly="False" SortExpression="Select">
<ItemStyle HorizontalAlign="Center" />
</asp:CheckBoxField>
</Columns>
However, because a GridView is designed for Row-By-Row editing, all the resulting CheckBoxes are disabled and cannot be checked. This is because their containing row is not in Edit Mdoe. I do not want to enable Row-By-Row editing using a button or similar metaphor as the user often needs to check off several rows. More clicks is bad, and annoying. They should be focused soley on their data and making their selection, not worrying about remembering to enter and end edit mode. Also, the metaphor seems poorly placed here since the checkboxes are the -ONLY- editable data - and are not part of the represented data.
I could, of course, make a new class which inherits from GridView, overload the method which generates columns to produce checkboxes instead of text fields - but I felt there had to be a more straightforward path. Maybe this is the way to go? But maybe it would have the same editing issue as above - I'm not sure.
So, next I tried looking at using an asp:TemplateField as a column in my GridView. This TemplateField contains an asp:CheckBox who's Checked state is based on the underlying bound data value. The issue here is trying to make changing the check-state update that bound value. I would need some way of looking up a GridView value I could then use to find the same row in the DataTable. I've seen great examples using a Primary Key. While I could assume everyone keeps a Primary Key for any possible table, this might not be the case! I could further add a Primary Key myself, but now it looks like I would be adding and removing two columns before I pass a DataTable off to a WebService instead of just one. Again, I also would need to be able to assign a Column name which is dynamic to avoid collision.
<asp:TemplateField HeaderText="Select">
<ItemTemplate>
<asp:CheckBox runat="server" ID="CheckBox"
Checked="<%# DataBinder.Eval(Container.DataItem, "Select") %>"
AutoPostBack="true" OnCheckedChanged="SelectCheckBox_CheckChanged" />
</ItemTemplate>
</asp:TemplateField>
I stopped myself - This path is also fairly indirect. Surely there is a much cleaner, simpler way to do this. Is it uncommon for someone to display Read-Only data where records are selected to be submitted, in one fashion or another, for processing/updating/alteration?
Is my choice of GridView poor? I haven't yet found another good way to represent Table data.
I have a DevExpress ASPx GridView control and am trying to implement sorting for the grid columns.
The gridView contains has integer values in one column, text in the rest. I also have a column which contains hyperlinks and is added through the code behind during run time.
I am using the Aspxgrid_CustomColumnSort event for sorting the grid.
I can achieve the sorting for the column which contains the integer values and texts successfully, however the same code is not working for the column with hyperlinks.
When I click on the column header the hyperlinks sorts in ascending order,
but when I click the header the second time the grid isnt getting sorted in the descending order, the hyperlinks are sorted in randomn order ( neither ascending nor descending)
And, further clicks on the header do not do anything.
Any advice/suggestion will be greatly appreciated.
Maybe this link will help: http://www.devexpress.com/Support/Center/p/B145444.aspx. In this page, someone had reported an issue using the GridViewDataHyperLinkColumn.
I need to color code two GridViews. The color coding should expose data discrepancies between the two GridViews. The data is stored in DataTables. Since the DataTable may be used for different controls, I’d prefer to flag the data discrepancy within the DataTable.
Well, to use the DataTable for flagging, you would have to add an extra column to store the flag, so you could retrieve it in the RowDataBound event of the GridView to change the color. That is certainly possible; however, if for some reason that doesn't work, you could create a wrapper class for each row, that represents the row and has the additional data you need. That makes it more complex to bind, but it would work.
HTH.
I've got very dynamic GridView and I need to allow to user to edit first column of it. After he edit first column of grid it must be updated on DataBase.
Is there any ways to handle it ?
My only idea is to put some changeable element to first cell of each Row so it must be able to set / get my values for each row but can't find yet any examples of it ...
Additional info :
GridView takes data from Object data source and all columns are dynamic (yes, maybe except first, but I add it in dynamic way) and load complete DataTable... \
Currently Using jQuery+Ajax methode on dynamic button but can't disable button's PostBack so with a PostBack it just disappears and dont make the event it must to make...
Since you have dymanic columns, for each column, specify the read-only property (If a column is read-only, it may only be looked at, and not edited when in the GridView's Edit-Mode).
So, the first column of would be readonly="false" (or omit it entirely) and the other columns read-only="true".
I am using a Datagrid with several columns of data (call it myDG) and one of these columns is a DateTime bound to a datasource. Its value is dependent on a "job" object completing a job and assigning the date time value. Since this normally takes up to a minute the value is left unassigned at the beginning.
The column's asp.net definition is:
<asp:boundcolumn
DataField="CompletedDate"
HeaderText="Date Completed"
DataFormatString="{0:dd-MMM-yyyy <br> hh:mm:ss tt}" />
So the functionality works fine when the "job" has completed and it sets the time. But before that, while the row is being displayed, it shows as
01-Jan-0001
12:00:00 AM
I am wanting to hide this and determined that the best way would be to mask that particular row and column with a blank, or override the value temporarily. I am having problems doing this and finding a way to access that specific row and column.
It is the [3] column of the datagrid and always in the first row (since new rows are added at the top).
Is there a way to directly access this cell and temporarily 'hide' its contents, or mask them? Ideally it would be great if there was a way to blank out all rows that had a value equal to this in their column, but a way to manipulate the specific cell would work as well.
-thanks in advance!
I would probably hook OnItemDataBound, check the value, and replace/reformat if required.
I asked a similar question about hiding columns here.
I had to use the RowCreated event to hide certain columns from the user (PK columns) and this may help you out as well (especially with hiding databound columns).
I have done similar things in the past and here is what I have done.
Bind the data to a column that is not visible at all. Add a visible column for the data you wish to display. At the time you populate your grid, loop through the records and for any that have a value that isn't 01-Jan-0001 12:00:00 AM, set your visible row to that value. If it does equal 01-Jan-0001 12:00:00 AM, then set the value of your visible row to an empty string or some value of your choice. (You could even set the text color to the same as the background color so it wouldn't appear to the user)