Question

我没有解决这个问题。我有几个comboboxes从sql获取值来过滤表中的某些数据，问题是当用户选择combobox时，如果他想清除它，则无法选择所以，只选择另一个项目。

经过一些搜索，我添加了button来清除comboboxes，但我不想要那个解决方案，我想的是在每个组合框中创建一个空白区域来清除选择。

如何创建这样的空间，用户可以选择是否要删除选择。代码：

 private void vidro_Load(object sender, EventArgs e)
        {
            SqlDataAdapter SDA = new SqlDataAdapter("select distinct desempenho from vidros", con);
            DataTable DTT = new DataTable();
            SDA.Fill(DTT);
            desempenho.Items.Clear();
            foreach (DataRow ROW in DTT.Rows)
            {
                desempenho.Items.Add(ROW["desempenho"].ToString());
            }
            SqlDataAdapter SDA2 = new SqlDataAdapter("select distinct valu from vidros", con);
            DataTable DTT2 = new DataTable();
            SDA2.Fill(DTT2);
            valu.Items.Clear();
            foreach (DataRow ROW in DTT2.Rows)
            {
                valu.Items.Add(ROW["valu"].ToString());
            }
            SqlDataAdapter SDA3 = new SqlDataAdapter("select distinct fs from vidros", con);
            DataTable DTT3 = new DataTable();
            SDA3.Fill(DTT3);
            fsolar.Items.Clear();
            foreach (DataRow ROW in DTT3.Rows)
            {
                fsolar.Items.Add(ROW["fs"].ToString());
            }
            SqlDataAdapter SDA5 = new SqlDataAdapter("select distinct compo from vidros", con);
            DataTable DTT5 = new DataTable();
            SDA5.Fill(DTT5);
            select.Items.Clear();
            foreach (DataRow ROW in DTT5.Rows)
            {
                compo.Items.Add(ROW["compo"].ToString());
            }
            SqlDataAdapter SDA6 = new SqlDataAdapter("select distinct sel from vidros", con);
            DataTable DTT6 = new DataTable();
            SDA6.Fill(DTT6);
            select.Items.Clear();
            foreach (DataRow ROW in DTT6.Rows)
            {
                select.Items.Add(ROW["sel"].ToString());
            }
        }
        private void compo_SelectedIndexChanged_1(object sender, EventArgs e)
        {
            FillData();
        }
        private void select_SelectedIndexChanged(object sender, EventArgs e)
        {
            FillData();
        }
        private void fsolar_SelectedIndexChanged_1(object sender, EventArgs e)
        {
            FillData();
        }
        private void valu_SelectedIndexChanged_1(object sender, EventArgs e)
        {
            FillData();
        }
        private void desempenho_SelectedIndexChanged_1(object sender, EventArgs e)
        {
            FillData();
        }
        private void FillData()
        {
            string combo1value = desempenho.Text;
            string combo2value = valu.Text;
            string combo3value = fsolar.Text;
            string combo4value = select.Text;
            string combo5value = compo.Text;

            string query = "select [descri],[enchimento],[compo] from vidros where 1=1 ";
            string queryWhere = "";
            SqlDataAdapter sda = new SqlDataAdapter();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            sda.SelectCommand = cmd;

提前致谢

Answer 1

让我们以你的一个组合框为例：

desempenho.Items.Clear();
foreach (DataRow ROW in DTT.Rows)
{
     desempenho.Items.Add(ROW["desempenho"].ToString());
}
desempenho.Items.Items.Insert(0,"");

这样你的组合中第一个空项目，然后你必须在验证表格时检查它。

在组合框中添加一个空格以清除选择

1 个答案: