参数异常

Question

我正在制作一个简单的登录表单并收到以下异常

ArgumentException was caught. No mapping exists from object type System.Web.UI.WebControls.TextBox to a known managed provider native type.

这是 C# 代码

        SqlConnection con = new SqlConnection("Data source=.;Initial catalog=InvoiceSystem;user id =sa;password=rfm");
        SqlCommand cmd = new SqlCommand("spLogin", con);
        cmd.CommandType = CommandType.StoredProcedure;
        SqlParameter p1 = new SqlParameter("username", txtUsername);
        SqlParameter p2 = new SqlParameter("password", txtPassword);
        cmd.Parameters.Add(p1);
        cmd.Parameters.Add(p2);
        try
        {
            con.Open();
            SqlDataReader rd = cmd.ExecuteReader();
            if (rd.HasRows)
            {
                rd.Read();
                Response.Redirect("Default.aspx");
            }
            else
            {
                Response.Write("<script>alert('Invalid Username/Password')</script>");
            }
        }
        catch{

        }

Answer 1

您尝试将 TextBox 个对象发送到存储过程：

SqlParameter p1 = new SqlParameter("username", txtUsername);
SqlParameter p2 = new SqlParameter("password", txtPassword);

它不知道如何处理这些对象。相反，只需发送包含在这些文本框中的文本：

SqlParameter p1 = new SqlParameter("username", txtUsername.Text);
SqlParameter p2 = new SqlParameter("password", txtPassword.Text);

Answer 2

您正在将 TextBox 本身而不是它的文本值传递给 SqlParameter。将其更改为：

   SqlParameter p1 = new SqlParameter("username", txtUsername.Text);
   SqlParameter p2 = new SqlParameter("password", txtPassword.Text);

Answer 3

您必须像这样使用 .Text 属性提取文本：

SqlParameter p1 = new SqlParameter("username", txtUsername.Text);
SqlParameter p2 = new SqlParameter("password", txtPassword.Text);

参数异常

ArgumentException

c#

sql

stored-procedures

argumentexception

ionic-zip