Using Linq to filter a ComboBox.DataSource ?
- by Pesche Helfer
Hi board,
in another topic, I've stumbled over this very elegant solution by Darin Dimitrov to filter the DataSource of one ComboBox with the selection of another ComboBox:
how to filter combobox in combobox using c#
combo2.DataSource = ((IEnumerable<string>)c.DataSource)
.Where(x => x == (string)combo1.SelectedValue);
I would like to do a similar thing, but intead of filtering by a second combobox, I would like to filter by the text of a TextBox. (Basically, instead of choosing from a second ComboBox, the user simply enters his filter in to a TextBox). However, it turned out to be not as straight forward as I had hoped it would be. I tried stuff as the following, but failed miserably:
cbWohndresse.DataSource = ((IEnumerable<DataSet>)ds)
.Where(x => x.Tables["Adresse"].Select("AdrLabel LIKE '%TEST%'"));
cbWohndresse.DisplayMember = "Adresse.AdrLabel";
cbWohndresse.ValueMember = "Adresse.adress_id";
ds is the DataSet which I would like to use as filtered DataSource.
"Adresse" is one DataTable in this DataSet. It contains a DataColumn "AdrLabel". Now I would like to display only those "AdrLabel", which contain the string from the user input. (Currently, %TEST% replaces the textbox.text.)
The above code fails because the lambda expression does not return Bool. But I am sure, there are also other problems (which type should I use for IEnumerable? Now it's DataSet, but Darin used String. But how could I convert a DataSet to a string?
Yes, I am as much newbyish as it gets, my experience is "void", and publicly so. So please forgive me my rather stupid questions.
Your help is greatly appreciated, because I can't solve this on my own (tried hard already).
Thank you very much!
Pesche
P.S. I am only using Linq to achieve an uncomplicated filter for the ComboBox (avoiding a View). The rest is not based on Linq, but on oldstyle Ado.NET (ds is filled by an SqlDataAdapter), if that's of any importance.
