In this article, you will learn how to find System.DBNull.ToString has some invalid arguments
Server Error in '/' Application.
The best overloaded method match for 'System.DBNull.ToString(System.IFormatProvider)' has some invalid arguments
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: The best overloaded method match for 'System.DBNull.ToString(System.IFormatProvider)' has some invalid arguments
Source Error:
Line 1093: </div>
Line 1094: </div>
Line 1095: }
Line 1096:
Line 1097: <div class="row">
Solution: Check you are providing null values or problem with casting
The best overloaded method match for 'System.DBNull.ToString(System.IFormatProvider)' has some invalid arguments
public static byte[] CreateHTMLtoPDF(string HtmlString)
{
var htmlContent = String.Format(HtmlString);
var htmlToPdf = new NReco.PdfGenerator.HtmlToPdfConverter();
htmlToPdf.Orientation = NReco.PdfGenerator.PageOrientation.Landscape;
//var Orientation = new NReco.PdfGenerator.HtmlToPdfConverter().Orientation=NReco.PdfGenerator.PageOrientation.Landscape;
htmlToPdf.Size = NReco.PdfGenerator.PageSize.A4;
//htmlToPdf.Zoom = -0.55f;
var pageMargin = new NReco.PdfGenerator.HtmlToPdfConverter().Margins;
//htmlToPdf.PageHeight= 210;
//htmlToPdf.PageWidth = 297;
pageMargin.Left = 25;
pageMargin.Right = 25;
pageMargin.Bottom = 25;
pageMargin.Top = 25;
var pdfBytes = htmlToPdf.GeneratePdf(htmlContent);
byte[] bytes;
using (MemoryStream input = new MemoryStream(pdfBytes))
{
using (MemoryStream output = new MemoryStream())
{
string userpassword = "123";//Change it with User DOB Format dd-MM-yyyy
string Ownerpassword = "123";//Change it with whatever owner is wanted
PdfReader reader = new PdfReader(input);
PdfEncryptor.Encrypt(reader, output, true, userpassword, Ownerpassword, PdfWriter.ALLOW_SCREENREADERS);
bytes = output.ToArray();
//Response.ContentType = "application/pdf";
//Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf");
//Response.Cache.SetCacheability(HttpCacheability.NoCache);
//Response.BinaryWrite(bytes);
//Response.End();
}
}
return bytes;
}
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="SendOTP.aspx.cs" Inherits="Shoping_Cart.SendOTP" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>How to Send and Verify OTP On Mobile No Using C# In Asp.Net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
Mobile No:
<asp:TextBox ID="txtMobileNo" runat="server" Width="200px"></asp:TextBox>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Send OTP" />
<br />
<asp:Label ID="lblMessage" runat="server" Text=""></asp:Label>
</div>
</form>
</body>
</html>
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Shoping_Cart
{
public partial class SendOTP : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
try
{
Random r = new Random();
string OTP = r.Next(1000, 9999).ToString();
//Send message
string Username = "youremail@domain.com";
string APIKey = "YourHash";
string SenderName = "MyName";
string Number = "981111111";
string Message = "OTP code is - " + OTP;
string URL = "http://api.minifycode.in/send/?username=" + Username + "&hash=" + APIKey + "&sender=" + SenderName + "&numbers=" + Number + "&message=" + Message;
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URL);
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr = new StreamReader(resp.GetResponseStream());
string results = sr.ReadToEnd();
sr.Close();
Session["OTP"] = OTP;
//Redirect for varification
Response.Redirect("VerifyOTP.aspx");
}
catch (Exception ex)
{
lblMessage.Text = ex.Message.ToString();
}
}
}
}
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Verify.aspx.cs" Inherits="Cart.VerifyOTP" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Verify OTP</title>
</head>
<body>
<form id="form1" runat="server">
<div>
OTP:
<asp:TextBox ID="txtOTP" runat="server" Width="200px"></asp:TextBox>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Verify OTP" />
<br />
<asp:Label ID="lblMessage" runat="server" Text=""></asp:Label>
</div>
</form>
</body>
</html>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Cart
{
public partial class OTP : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
if (Session["OTP"].ToString() == txtOTP.Text)
{
lblMessage.Text = "You have enter correct OTP.";
Session["OTP"] = null;
}
else
{
lblMessage.Text = "Pleae enter correct OTP.";
}
}
}
}