如何在 C# 中的数据库中将 ID 插入文本框时获取名称
本文关键字:插入文本 获取 ID 数据库 | 更新日期: 2023-09-27 18:35:56
我正在处理以下代码
private void tbMemberID_TextChanged(object sender, EventArgs e)
{
try
{
//int RowsAffected = 0;
DataAccess oDataAccess = new DataAccess();
con.Open();
oDataAccess.cmd.CommandText = "SELECT MemberName FROM AccountInfo where MemberID='" + tbMemberID.Text + "'";
oDataAccess.cmd.Connection = con;
tbMemberName.Text = ((string)cmd.ExecuteScalar());
con.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
当我插入memberID
时,它显示错误
对象引用未设置为对象的实例
我的代码有问题吗?
您可能需要
从 sender
参数中获取它,例如:
private void tbMemberID_TextChanged(object sender, EventArgs e)
{
try
{
TextBox txtBox= sender as Textbox;
//int RowsAffected = 0;
DataAccess oDataAccess = new DataAccess();
con.Open();
oDataAccess.cmd.CommandText = "SELECT MemberName FROM AccountInfo where MemberID='" + txtBox.Text + "'";
oDataAccess.cmd.Connection = con;
tbMemberName.Text = ((string)cmd.ExecuteScalar());
con.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
另外,请注意sql注入