C# 如何从listbox c刷新标签值

大家好，我正在寻找有关我的代码的任何帮助，我需要解决从列表框刷新标签中的值的问题。我用他的数据、比赛等来研究球员。。我想看看他在比赛中的具体得分，我可以从列表框中选择，看看他在我交换比赛时的死伤情况，有人知道吗？谢谢你的关注。对不起我的英语。Lanky是Lans，Jménohráče是名字，Věk是年龄，Země是国家。波切特·基鲁意味着死亡数，另一个意味着死亡数，维克尔·奥德兰奇意味着他所有的比赛

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    connection = new SqlConnection(connectionstring);
    try
    {
        connection.Open();
        var q = "SELECT * FROM Lanky";
        var query = new SqlCommand(q, connection);
        using (var dr = query.ExecuteReader())
        {
            var success = dr.Read();
            if (success)
            {
                label8.Text = dr["Kills"].ToString();
                label9.Text = dr["Deaths"].ToString();
                label1.Text = dr["Jménohráče"].ToString();
                label2.Text = dr["Věk"].ToString();
                label3.Text = dr["Země"].ToString();

            }
        }
        connection.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show("error " + ex);
    }

}

---

[

应该有一个方法填充listbox，另一个方法在listbox select上激发。您已经在listbox changed事件中放置了数据检索。请执行以下操作：

 private void Form1_Load(object sender, EventArgs e)
        {
            connection = new SqlConnection(connectionstring);
            try
            {
                connection.Open();
                var q = "SELECT * FROM Lanky";
                var query = new SqlCommand(q, connection);
                using (var dr = query.ExecuteReader())
                {

                    ListBox1.Items.Clear();
                    while (dr.Read())
                    {
                        ListBox1.Items.Add(dr["Jménohráče"]);
                    }
                }

                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error " + ex);
            }

        }

private void ListBox1_SelectedItemChanged(object sender, EventArgs e)
{
    connection = new SqlConnection(connectionstring);
    try
    {
        connection.Open();
        var q = "SELECT * FROM Lanky WHERE Jménohráče  = @jh";
        var query = new SqlCommand(q, connection);
        query.Parameters.Add("@jh", ListBox1.SelectedValue.ToString())
        using (var dr = query.ExecuteReader())
        {

            ListBox1.Items.Clear();
            dr.Read();

            label8.Text = dr["Kills"].ToString();
            label9.Text = dr["Deaths"].ToString();
            label1.Text = dr["Jménohráče"].ToString();
            label2.Text = dr["Věk"].ToString();
            label3.Text = dr["Země"].ToString();

        }

        connection.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show("error " + ex);
    }

}

首先，将代码从listbox1\u SelectedItemChanged移动到Form\u Load event，如下所示：

 private void Form1_Load(object sender, EventArgs e)
        {
            connection = new SqlConnection(connectionstring);
            try
            {
                connection.Open();
                var q = "SELECT * FROM Lanky";
                var query = new SqlCommand(q, connection);
                using (var dr = query.ExecuteReader())
                {

                    ListBox1.Items.Clear();
                    while (dr.Read())
                    {
                        ListBox1.Items.Add(dr["Jménohráče"]);
                    }
                }

                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error " + ex);
            }

        }

private void ListBox1_SelectedItemChanged(object sender, EventArgs e)
{
    connection = new SqlConnection(connectionstring);
    try
    {
        connection.Open();
        var q = "SELECT * FROM Lanky WHERE Jménohráče  = @jh";
        var query = new SqlCommand(q, connection);
        query.Parameters.Add("@jh", ListBox1.SelectedValue.ToString())
        using (var dr = query.ExecuteReader())
        {

            ListBox1.Items.Clear();
            dr.Read();

            label8.Text = dr["Kills"].ToString();
            label9.Text = dr["Deaths"].ToString();
            label1.Text = dr["Jménohráče"].ToString();
            label2.Text = dr["Věk"].ToString();
            label3.Text = dr["Země"].ToString();

        }

        connection.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show("error " + ex);
    }

}

接下来，在selectedItem changed中执行以下操作：

 private void Form1_Load(object sender, EventArgs e)
        {
            connection = new SqlConnection(connectionstring);
            try
            {
                connection.Open();
                var q = "SELECT * FROM Lanky";
                var query = new SqlCommand(q, connection);
                using (var dr = query.ExecuteReader())
                {

                    ListBox1.Items.Clear();
                    while (dr.Read())
                    {
                        ListBox1.Items.Add(dr["Jménohráče"]);
                    }
                }

                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error " + ex);
            }

        }

private void ListBox1_SelectedItemChanged(object sender, EventArgs e)
{
    connection = new SqlConnection(connectionstring);
    try
    {
        connection.Open();
        var q = "SELECT * FROM Lanky WHERE Jménohráče  = @jh";
        var query = new SqlCommand(q, connection);
        query.Parameters.Add("@jh", ListBox1.SelectedValue.ToString())
        using (var dr = query.ExecuteReader())
        {

            ListBox1.Items.Clear();
            dr.Read();

            label8.Text = dr["Kills"].ToString();
            label9.Text = dr["Deaths"].ToString();
            label1.Text = dr["Jménohráče"].ToString();
            label2.Text = dr["Věk"].ToString();
            label3.Text = dr["Země"].ToString();

        }

        connection.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show("error " + ex);
    }

}

---

您好，在列表框中有一个处理更改事件的选项，因此实现该函数，在该函数中，您可以基于此获取选定值您必须更新标签您的查询应该类似于SELECT*FROM Lanky，其中MatchId=+id；id来自listBox1.SelectedItem.Ye，但任何人都知道如何更改值标签中的es？因为我可以看到12个死亡和10个死亡，但当我单击NHL时，标签仍然不会更改12/10…但在我的数据库中，NHL中有20个KIL和12个死亡匹配。您可以将Listbox AutoPostBack属性更改为True。如果不希望页面回发，请使用scriptmanager。