how to update combobox with items from DB

Nuno Teodoro

Hi all.
I've been searching for this for some time but still i'm not able to update my comboboxes. The scenarios is as following: i have a combobox with items from a sql database. I have an add and remove button for adding and removing values from the database table where that combobox is receiving the values. The thing is when i add or remove, it adds or removes from the database but the combobox will not reproduce those changes in runtime. How can i do that? I've tryied to inicialize the combobox all over again the same way it does when the application first starts but all i get is or an empty combobox or the items remain the same.

I really would like some help in this matter.

Thank you all!!

3 Replies

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Nuno Teodoro17y ago
maybe my problem is in the datasource itself, because i always get an empty combobox now with this code, but i think this should be the way to do it, take a look please.

System.Windows.Forms.BindingSource novoBind = new BindingSource();
            GEP.DS_Averiguadores dS_Averiguadores = new GEP.DS_Averiguadores();
            GEP.DS_AveriguadoresTableAdapters.AveriguadoresTableAdapter averiguadoresTableAdapter = new GEP.DS_AveriguadoresTableAdapters.AveriguadoresTableAdapter();

            averiguadoresTableAdapter.ClearBeforeFill = true;

            dS_Averiguadores.DataSetName = "DS_Averiguadores";
            dS_Averiguadores.SchemaSerializationMode = System.Data.SchemaSerializationMode.IncludeSchema;

            novoBind.DataMember = "Averiguadores";
            novoBind.DataSource = dS_Averiguadores;

            comboBox1.DataSource = novoBind;

            comboBox1.AccessibleName = "comboBox1";
            comboBox1.AllowDrop = true;
            comboBox1.Cursor = System.Windows.Forms.Cursors.Default;
            comboBox1.DisplayMember = "Nome";
            comboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            comboBox1.FormattingEnabled = true;
            comboBox1.Location = new System.Drawing.Point(121, 24);
            comboBox1.Name = "comboBox1";
            comboBox1.Size = new System.Drawing.Size(187, 21);
            comboBox1.TabIndex = 2;
            comboBox1.ValueMember = "Nome";

thank you!
Nuno Teodoro17y ago
well, despite that problem, what i did was:

DS_Averiguadores test= new DS_Averiguadores();

comboBox1.DataSource = teste;

Where DS_Averiguadores is the datasouce i'm using.

After that, what i obain in the combobox is this:

System.Data.DataViewManagerList|ter
Nuno Teodoro17y ago
well the thing now is that i have the main interface ( a win form) and then when pressing the add button it open another win form for value input and with an ok button. After pressing ok what it is doing is: go to the data link layer -> perform the operation for addin in the database, update values in combobox in main interface and finally close this input form.
I have the problem that, for accessing the combobox in the main interface i have to do it in the main interface code and i cant create a static method to be called by the input interface you see? This is because the combobox is created private and if i modifi it to be static like public static combobox; it automatically put's it in private again after some time!