Combobox in Database

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Combobox in Database

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#1 by (2 votes)
#2 by (1 votes)
#3 by (1 votes)

3

I always used Delphi and there was a component called DBLookupcombobox where it was possible to list the data of a table and use the ID field of this referenced saving in the main table, for example:

In an Employee registry I have the ID_Cidade that is FK of the Cidade table, with DBLookupcombobox I showed the city name and in the component properties I could save the ID_cidade in the Funcionário table, does the Combobox do this in C #?

Configuring it by properties ?

c# winforms combobox

asked by anonymous 01.02.2015 / 03:21

3 answers

How do I remove the parent element and all its contents when child element is clicked? Add field in position I want in sql server

score 2 · Answer 1

In the Load event:

cboClientes.DataSource = null;
cboClientes.ValueMember = "id";
cboClientes.DisplayMember = "Nome";
cboClientes.DataSource = _dt;
if (cboClientes.DataSource != null)
{
    cboClientes.SelectedIndex = 0;
}
cboClientes.Refresh();

Just set up the events:

private void cboClientes_SelectedIndexChanged(object sender, EventArgs e)
{
    cboClientes.SelectedValue = idCliente;
}

private void cboClientes_SelectionChangeCommitted(object sender, EventArgs e)
{
    idCliente = (int)cboClientes.SelectedValue;
}

score 1 · Answer 2

Julian, I made a very simple example using EntityFramework as the data source for the combo box, the complete code you can see here

I also took the opportunity to create an example in ASP.NET MVC, which you can see here

Popular ComboBox

private void Form1_Load(object sender, EventArgs e)
{
    using (ComboBoxDBContext context = new ComboBoxDBContext())
    {
        comboBox1.DataSource = context.ProdutoGrupos.ToList();
        comboBox1.ValueMember = "ProdutoGrupoId";
        comboBox1.DisplayMember = "Descricao";
        comboBox1.Refresh();
    }
}

Retrieve the selected value

private void button1_Click(object sender, EventArgs e)
{
    using (ComboBoxDBContext context = new ComboBoxDBContext())
    {
        Produto produto = new Produto();
        produto.ProdutoGrupoId = Convert.ToInt32(comboBox1.SelectedValue);
        produto.Descricao = textBox1.Text;
        context.Produtos.Add(produto);
        context.SaveChanges();
     }
}

From experience also being a programmer who left Delphi, I tell you to slightly abstract the issue of configuration by properties. Not that this is not possible, but every time I tried to work on Windows Forms linking properties, I was a little frustrated.

score 1 · Answer 3

A simple way, and I use this in the software I made was the following (I will use as an example a list of Brazilian states, but may be the data returned from the database):

I read the values from another list / data source and switched to the combobox as follows:

combo.DataSource = new BindingSource(new Dictionary<string, string>()
{
    { "AC", "AC" },
    { "AL", "AL" },
    { "AP", "AP" },
    { "AM", "AM" },
    { "BA", "BA" },
    { "CE", "CE" },
    { "DF", "DF" },
    { "ES", "ES" },
    { "GO", "GO" },
    { "MA", "MA" },
    { "MT", "MT" },
    { "MS", "MS" },
    { "MG", "MG" },
    { "PA", "PA" },
    { "PB", "PB" },
    { "PR", "PR" },
    { "PE", "PE" },
    { "PI", "PI" },
    { "RJ", "RJ" },
    { "RN", "RN" },
    { "RS", "RS" },
    { "RO", "RO" },
    { "RR", "RR" },
    { "SC", "SC" },
    { "SP", "SP" },
    { "SE", "SE" },
    { "TO", "TO" }
}, null);

combo.DisplayMember = "Value";
combo.ValueMember = "Key";

Value of the Combobox, you point it to the BindingSource of the table you want to save to the linked property in ValueMember.