C＃数据绑定列表框刷新

Question

I've checked the answers on this topic however I still have no idea why this is not working! PLEASE HELP!

    private void btnAdd_Click(object sender, EventArgs e)
    {
        SqlCeCommand insTitle = new SqlCeCommand("Insert into Titles(Title) values('" + txtAddTitle.Text +"')");
        insTitle.Connection = dbConnection;

        try 
        {
            if (dbConnection.State == ConnectionState.Closed) { dbConnection.Open(); }
            insTitle.ExecuteNonQuery();


            this.hRDataSet.AcceptChanges();
            this.titlesTableAdapter.Update(this.hRDataSet);
            this.tableAdapterManager.UpdateAll(this.hRDataSet);

            lstTitles.BeginUpdate();
            lstTitles.DataSource = titlesBindingSource;
            lstTitles.DisplayMember = "Title";
            lstTitles.ValueMember = "Title_ID";
            lstTitles.EndUpdate();
        }
        catch (Exception insErr)
        {
            MessageBox.Show(insErr.Message);
        }
    }

The listbox "lstTitles" won't refresh and doesn't show the added items despite the fact that they are in the database!

Answer 1

The Update method of the DataAdapter is used to update the database with the changes made in the DataSet . What you need to do here is the opposite: you need to update the DataSet with the modified data from the database, so you should use Fill , not Update .

Anyway, your approach is not optimal; since you're working with datasets, you should add the new value to the appropriate table in the DataSet , and then update the database with the Update method. The ListBox will automatically pick up the changes.

private void btnAdd_Click(object sender, EventArgs e)
{
    try 
    {
        // Add a row to the DataTable
        DataRow row = hRDataSet.Titles.NewRow();
        row["Title"] = txtAddTitle.Text;
        hRDataSet.Titles.Rows.Add(row);

        // Update the database
        this.titlesTableAdapter.Update(this.hRDataSet);

        // That's it, you're done ;)
    }
    catch (Exception insErr)
    {
        MessageBox.Show(insErr.Message);
    }
}