ASP.NET 注册页面检验用户名是否存在的代码怎么写？
注册页面用了数据验证控件
写了下面一段代码：
protected void LinkButton8_Click(object sender, EventArgs e)
{
string Constring = "Provider=SQLOLEDB;Data Source=.;Integrated Security=SSPI;Initial Catalog=shopingdb";
OleDbConnection conn = new OleDbConnection(Constring);
string sql = "select * from users where userName='";
sql += txb_name.Text.Trim() + "'";
OleDbCommand cmd = new OleDbCommand(sql, conn);
OleDbDataReader dr;
conn.Open();
dr = cmd.ExecuteReader();
if (dr.Read())
{
LinkButton8.Text = "用户名已经被注册，请重新输入可用的用户名";
txb_name.Text = "";
}
else
LinkButton8.Text = "该用户名可用！";
}
但是我一单击该按钮，它只是执行验证控件，上面代码根本没发生作用，请问如何解决？请提供代码。
private bool Is_Exist()
{string Constring = "Provider=SQLOLEDB;Data Source=.;Integrated Security=SSPI;Initial Catalog=shopingdb";
OleDbConnection conn = new OleDbConnection(Constring);
string sql = "select * from users where userName='";
sql += txb_name.Text.Trim() + "'";
OleDbCommand cmd = new OleDbCommand(sql, conn);
OleDbDataReader dr;
conn.Open();
dr = cmd.ExecuteReader();
if (dr.Read())
{
txb_name.Text = "";
return true;
}
else
return false;
}
再在button中写代码
protected void LinkButton8_Click(object sender, EventArgs e)
{
if(!Is_Exist())
{
//不存在该用户，可注册
}
else//存在返回
{
}
}
