Question

我有ID的文本框。我希望用户输入ID，当他按下Enter键时，我从数据库中获取该特定ID的一些信息。

如何描述按键描边？

Answer 1

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if (e.KeyChar == (char) Keys.Return)
    {
        ...
    }
}

Answer 2

也许这可以帮到你：

public string GetSomethingFromID(string ID)
    {
        try
        {
            string cmdString = "SELECT columnName FROM tableName WHERE ID='" + ID + "'";

            SqlConnection con = new SqlConnection(connectionString);  // create your connection string and write it's name.
            con.Open();

            SqlCommand command = new SqlCommand(cmdString, con);
            SqlDataReader sdr = command.ExecuteReader();
            sdr.Read();
            string something = sdr[0].ToString();

            con.Close();
            return something;
        }
        catch
        {
            return null;
        }
    }

然后在你的textBox上按下键时：

private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
    if(e.KeyData == Keys.Enter)
       textBox2.Text = GetSomethingFromID(textBox1.Text);
}

按ENTER键后执行一些代码

2 个答案: