Question

<asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="txtbx1" ValidateEmptyText="true" OnServerValidate="validating" Text="Please Enter Name!" ></asp:CustomValidator>

我已经尝试过了，只是可以了，但是我不知道如何阻止数据输入！。

   protected void Button1_Click(object sender, EventArgs e)
    {
        string a = txtbx1.Text;
        string b = txtbx2.Text;
        string c = txtbx3.Text;
        string d = txtbx4.Text;
        string es = txtbx5.Text;
        string f = txtbx6.Text;
        if (txtbx1.Text.ToString().Equals(a) || txtbx2.Text.ToString().Equals(b) || txtbx3.Text.ToString().Equals(c) || txtbx4.Text.ToString().Equals(d) || txtbx5.Text.ToString().Equals(es) || txtbx6.Text.ToString().Equals(f))

        {
            try
            {
                SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["cs"].ConnectionString);
                using (conn)
                {
                    SqlCommand cmd = new SqlCommand("addstd", conn);
                    cmd.Parameters.AddWithValue("@name", txtbx1.Text);
                    cmd.Parameters.AddWithValue("@fathername", txtbx2.Text);
                    cmd.Parameters.AddWithValue("@enrollment", txtbx3.Text);
                    cmd.Parameters.AddWithValue("@email", txtbx4.Text);
                    cmd.Parameters.AddWithValue("@batchcode", txtbx5.Text);
                    cmd.Parameters.AddWithValue("@semester", txtbx6.Text);

                    conn.Open();
                    cmd.CommandType = System.Data.CommandType.StoredProcedure;
                    cmd.ExecuteNonQuery();
                }
                Response.Write("<script language=javascript>alert('Inserted Successfully!')</script>");
            }
            catch (Exception)
            {
                throw;
            }
        }
        else if (txtbx1.Text.Trim() == string.Empty || txtbx2.Text.Trim() == string.Empty ||txtbx3.Text.Trim() == string.Empty || txtbx4.Text.Trim() == string.Empty || txtbx5.Text.Trim() == string.Empty || txtbx6.Text.Trim() == string.Empty)
        {
            Label1.Visible = true;
            Label1.Text = "Please Enter Complete Information!";

        }
    }

这是我尝试过的完整代码，但没有用，即使文本框为空，它仍然会显示错误消息，而且还会提交数据

Answer 1

我不明白为什么要进行如下检查。

if (txtbx1.Text.ToString().Equals(a) || txtbx2.Text.ToString().Equals(b) || txtbx3.Text.ToString().Equals(c) || txtbx4.Text.ToString().Equals(d) || txtbx5.Text.ToString().Equals(es) || txtbx6.Text.ToString().Equals(f))
{
  // your code
}

将上述代码替换为您的else部分。

if (txtbx1.Text.Trim() == string.Empty || txtbx2.Text.Trim() == string.Empty ||txtbx3.Text.Trim() == string.Empty || txtbx4.Text.Trim() == string.Empty || txtbx5.Text.Trim() == string.Empty || txtbx6.Text.Trim() == string.Empty)
{
  Label1.Visible = true;
  Label1.Text = "Please Enter Complete Information!";
}
else
{
  //database save logic
}

除此之外，必需的字段验证器应该可以工作。

文本框为空时如何防止数据在数据库中提交

1 个答案: