组合框中的选定值不读取 [英] Selected Values in a combobox is not reading

问题描述

cmd = new SqlCommand("select intrfacname from transfer where ipad='" + comboBox2.SelectedItem.ToString() + "'", cn.con);
dr1 = cmd.ExecuteReader();
while (dr1.Read())
{
    textBox2.Text = dr1[0].ToString();
}
dr1.Dispose();
cmd.Dispose();

Am选择组合框值并读入文本框但该选定索引的值未读取字符串在dis代码之前我绑定组合框中的值，其代码在这里，但它的工作原理

Am Selecting the combo box value and read into an text box but value of that selected index is not reading in a string Before dis code i bind the values in combo box the code for that is here but it works

 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
  cmd = new SqlCommand("select ipad from transfer where ntwrk='" + comboBox1.SelectedItem.ToString() + "'", cn.con);
            

            dr = cmd.ExecuteReader();
            DataTable dt = new DataTable();

            dt.Columns.Add("ipad", typeof(string));
           // dt.Columns.Add("contactname", typeof(string));
            dt.Load(dr);

            comboBox2.ValueMember = "ipad";
            comboBox2.DisplayMember = "ipad";
            comboBox2.DataSource = dt;
            cmd.Dispose();
            dr.Dispose();
}

但上面的读取代码的代码不起作用帮我解释

But the above code for reading a value does not work help me pls

推荐答案

只是更新它... ....

Just Update itlike that....:)

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
  cmd = new SqlCommand("select ipad from transfer where ntwrk='" + comboBox1.SelectedItem.ToString() + "'", cn.con);
            
 
            dr = cmd.ExecuteReader();
            DataTable dt = new DataTable();
 
            dt.Columns.Add("ipad", typeof(string));
           // dt.Columns.Add("contactname", typeof(string));
            dt.Load(dr);
 
            comboBox2.DataSource = dt;
            comboBox2.ValueMember = "ipad";
            comboBox2.DisplayMember = "ipad";
           
            cmd.Dispose();
            dr.Dispose();
}

你可以试试这个：

comboBox1.SelectedValue。 ToString（）;

Hi,
you can try this:
comboBox1.SelectedValue.ToString();

试试这个...... :)

Try this....:)

cmd = new SqlCommand("select intrfacname from transfer where ipad='" + comboBox2.SelectedItem.ToString() + "'", cn.con);
         dr1 = cmd.ExecuteReader();
         while (dr1.Read())
         {
             textBox2.Text = dr1[0]["intrfacname"].ToString();
         }
         dr1.Dispose();
         cmd.Dispose();

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