Asp: can you set the visible text in a drop down list?

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I have various DDLs which give the user access to previous entries in the row being edited. It works fine, except that it would look better if the DDLs appeared as just the arrow without the text alongside it. I assume the DDLs automatically fill this text with whatever the first entry is, based on the SQL command the DDL draws from, but can this be disabled or adjusted somehow?

Edit: Immediately after posting this I found out you can restrict the width of the DDL to force it to display just the arrow. Leaving this up in case someone else comes along looking for the same answer.

What I have tried:

Setting the DLL's OnClick to run a function that executes the correct SQL command. For some reason this resulted in the DDL's arrow doing nothing at all when clicked.

Posted 28-Jun-18 3:28am

OlivesForDinner

Updated 28-Jun-18 3:37am

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Richard Deeming 28-Jun-18 11:54am

If you just want the list to be blank until the user selects an item, then add a blank item to the start of the list.

Changing the width so that the user can't see which item is selected sounds like a bad UI.

OlivesForDinner 28-Jun-18 13:19pm

It's visually identical to adding a blank item, as far as I can tell. It merely results in the arrow box displaying with nothing next to it, which is what I was after. Why is that bad?

Richard Deeming 28-Jun-18 13:24pm

Because the user can't see what they've selected.

OlivesForDinner 28-Jun-18 13:27pm

No. What you've selected is visible. As I said, only the button is affected.

Vincent Maverick Durano 28-Jun-18 22:05pm

Displaying just an arrow might confuse some of the users viewing it. They might think the DropDowns does not contain anything in it. If you don't want to add a blank entry on the first item, you could add an item that displays something like "Select" or "------" just to draw users attention to select something from the DropDown.

Anyway that's just my point of views. If what you have right now works for your client then there's no one stopping you ;)

OlivesForDinner 29-Jun-18 9:02am

There are two orthogonal issues here.

One is that what is selected before the user clicks the DDL doesn't matter because the DDLs are populated with edit history data. It's an undo button that goes back several edits and lets you choose which previous input to go back to. This functionality is explained to the user.

The second is that I'm unable to add a blank (or dummy) entry. I'm not at all insisting on one solution over another here; this is just the one I have available to me. I'm new to ASP and nothing I've tried does anything more than throw an exception that says I'm referencing an object that isn't there.

For instance, if gv is my GridView:

((DropDownList)gv.Rows[gv.EditIndex].FindControl("nameofDDL")).Items.Add("");

produces this exception. What's weird about that is I've used this same sort of thing to refer to other controls with no issue. I can refer to a control that's in the same Edit Template as this DDL just fine. It has practically the same path. I really don't understand.

Vincent Maverick Durano 29-Jun-18 11:40am

accessing controls on edit mode requires extra checking as you need to determine the state of the GridView. For example:

if (e.Row.RowType == DataControlRowType.DataRow)   {        
    if ((e.Row.RowState & DataControlRowState.Edit) > 0) {            
        DropDownList ddl = (DropDownList)e.Row.FindControl("YourDropDownListID");        
    }
}

OlivesForDinner 29-Jun-18 12:13pm

Thanks for this. It helps a lot; I wanted to set up that kind of validation, but wasn't sure how to. Could you look at another question of mine related to this? Seems like you might know what's going on.

https://www.codeproject.com/Questions/1250501/Gridview-editindex-not-updating-possibly-related-t

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