[英]Value ComboBox Change Value Of TextBox In C#
您好专家,我在一段时间前使用此代码,现在可以工作,但是现在不起作用...! 它说
(将varchar值'System.Data.DataRowView'转换为数据类型int时转换失败)
代码是combobox选择值更改文本框,其中包含该值的详细信息并预先感谢您。
public partial class test : Form
{
SqlConnection cn = new SqlConnection("Server=AMEER;DataBase=custemer_net;Integrated security=true");
SqlDataAdapter da;
DataTable dt = new DataTable();
DataTable dttt = new DataTable();
public test()
{
InitializeComponent();
da = new SqlDataAdapter("Select *from subscrbtion ", cn);
da.Fill(dt);
comboBox1.DisplayMember = "name";
comboBox1.ValueMember = "id";
comboBox1.DataSource = dt;
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
da = new SqlDataAdapter("select * from subscrbtion where id='" + comboBox1.SelectedValue + "'", cn);
da.Fill(dttt);
textBox1.Text = dttt.Rows[0]["phone"].ToString();
}
我认为您的SqlDataAdapter有问题:
new SqlDataAdapter("select * from subscrbtion where id='" + comboBox1.Text + "'", cn);
应该
new SqlDataAdapter("select * from subscrbtion where id='" + comboBox1.SelectedValue + "'", cn);
SelectedValue将指向您在ValueMember下声明的ID。
额外:在声明组合框数据源的数据/值成员之后,设置其:
comboBox1.DisplayMember = "name";
comboBox1.ValueMember = "id";
comboBox1.DataSource = dt;
请根据以下内容更改代码:
public test()
{
InitializeComponent();
using(SqlConnection cn = new SqlConnection("Server=AMEER;DataBase=custemer_net;Integrated security=true"))
{
var adapter = new SqlDataAdapter("Select *from subscrbtion ", cn);
adapter.Fill(dt);
}
comboBox1.DisplayMember = "name";
comboBox1.ValueMember = "id";
comboBox1.DataSource = dt;
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//for testing
MessageBox.Show(comboBox1.SelectedValue.ToString());
//
//clear the datatable dttt
dttt.Clear(); //<----------THIS SHOULD BE YOUR NEW SOLUTION
//refill the datatable with the new information
using(SqlConnection cn = new SqlConnection("Server=AMEER;DataBase=custemer_net;Integrated security=true"))
{
var adapter = new SqlDataAdapter("select * from subscrbtion where id='" + comboBox1.SelectedValue + "'", cn);
adapter.Fill(dttt);
}
//for testing
MessageBox.Show(dttt.Rows.Count.ToString());
//
//show the data inside the textbox.
textBox1.Text = dttt.Rows[0]["phone"].ToString();
}
让我知道消息框的内容
编辑:根据msdn:SqlDataAdapter.Fill()方法ADDS数据库内部的值。 ==>当然,这意味着测试消息框总是随行增加的原因。
我在上面的代码中添加了值,希望对您有所帮助
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