在ASP.NET的C＃中更新DropDownList的DataSource

Question

I have an edit form that uses a DropDownList, connected to a SQL server table using a DataSource. This edit form allows users to set the table's "IsDeleted" column value to 1, which would then hide it from all of the application's queries. (So the transaction still exists in the database, but not in the application)

The problem I've encountered with this is that if the page on which the edit form is is not left entirely, and then entered again, the entry still remains in the DataSource.

So essentially, the DataSource is not updating. (It's not running its select statement and repopulating until the whole page is reloaded). I've tried to use a page refresh and it doesn't seem to work, only going to a different page entirely and then coming back seems to update the DataSource.

How would I refresh the contents of the DataSource programmatically without having to recreate the entire DataSource itself?

Answer 1

You might want to add some code next time. My best guess for now is that you're not doing anything OnPostback.

Answer 2

So I eventually resorted to doing what I did not want to do in the hopes that there would be a "Best-practice" way to do it (and one hopefully already built-in into DataSources), but it seems that was not to be.

All it took was to re-assign the DataSource's parameters to it again and then assign the DataSource back to the DropDownList, as if I were creating a new one.

I created the following method, which I then called at the end of my Delete button's event.

protected void DropDownList_Reload()
    {
        MyDataSource.ConnectionString = ConfigurationManager.ConnectionStrings["MyDatabase"].ConnectionString;
        MyDataSource.SelectCommand = "SELECT * FROM [tblMyTable] WHERE [IsDeleted] <> 1";

        cbxDropDownList.DataSourceID = "MyDataSource";
        cbxDropDownList.DataTextField = "MyHeader";
        cbxDropDownList.DataValueField = "MyHeader";
    }