I am not sure why the callback methods are not fired AT ALL. I am using VS 2010.
static void Main(string[] args)
{
try
{
var url = "some link to RSS FEED";
var client = new WebClient();
client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
client.DownloadDataCompleted += new DownloadDataCompletedEventHandler(client_DownloadDataCompleted);
client.DownloadStringAsync(new Uri(url));
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
// THIS IS NEVER FIRED
static void client_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
{
Console.WriteLine("something");
}
// THIS IS NEVER FIRED
static void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
Console.WriteLine("do something");
var rss = XElement.Parse(e.Result);
var pictures = from item in rss.Descendants("channel")
select new Picture
{
Name = item.Element("title").Value
};
foreach (var picture in pictures)
{
Console.WriteLine(picture.Name);
Console.WriteLine(picture.Url);
}
}
The DownloadDataCompleted event is fired if you call the DownloadDataAsync() method. DownloadStringCompleted is fired if you call the DownloadStringAsync() method.
To get the DownloadDataCompleted event to fire, try:
static void Main(string[] args)
{
try
{
var url = "http://blog.gravitypad.com";
//client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
client.DownloadDataCompleted += new DownloadDataCompletedEventHandler(client_DownloadDataCompleted);
client.DownloadDataAsync(new Uri(url));
Console.ReadLine();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
I had this problem and realized that the uri was not correct. I mean the event wont fire unless the file is read correctly. So I placed my xml file in ClientBin and it worked like magic!
Related
I have a method called NewBatch_GetAndSetBatchID.
When I call this methode in the Page_Load methode it works perfectly.
But when I call this methode from a button (on the same page), I get:
Null reference exeption Object reference not set to an instance of an object.
It throws an error at:
BatchNoTextBox.Text = (batchID += 1).ToString();
When I debug, I can see that my batchID is filled with a value.
This is my code:
public void NewBatch_GetAndSetBatchID()
{
FormView1.ChangeMode(FormViewMode.Insert);
string connectionString = ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString;
try
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
SqlCommand sqlCommando = new SqlCommand("SELECT MAX(BatchNo) FROM BM_BrewBatchHeader", conn);
try
{
conn.Open();
batchID = Convert.ToInt32(sqlCommando.ExecuteScalar());
}
catch (Exception)
{
}
finally
{
conn.Close();
}
}
}
catch (SqlException error)
{
}
try
{
TextBox BatchNoTextBox = (TextBox)FormView1.FindControl("BatchNoTextBox");
BatchNoTextBox.Text = (batchID += 1).ToString();
}
catch (Exception)
{
throw;
}
}
What can be the problem here?
I found the solution on another forum:
I have to use the PreRender trigger from the FormView. With the code below it works fine. When I now set the Formview to insert or edit mode the code executes perfectly.
protected void FormView1_PreRender(object sender, EventArgs e)
{
// if the mode is Edit or Insert
if (this.FormView1.CurrentMode == FormViewMode.Edit || this.FormView1.CurrentMode == FormViewMode.Insert)
{
TextBox BatchNoTextBox = (TextBox)FormView1.FindControl("BatchNoTextBox");
BatchNoTextBox.Text = (batchID += 1).ToString();
}
}
I have an ASP.NET MVC application that uses SSRS for reporting (using a web form and report viewer). I would like to pass two parameters dynamically to the remote report. My current implementation stores the parameters in session, which works fine on VS Development Server, but the variable is null on IIS, upon retrieval in the web form.
Here is the controller method that calls the view
public ActionResult ShowReport(string id)
{
var reportParameters = new Dictionary<string, string>();
reportParameters.Add("Param1", id);
reportParameters.Add("Param2", "user1");
Session["reportParameters"] = reportParameters;
return View("ReportName");
}
And here is how I attempt to retrieve the parameters from the web form
protected void Page_Load(object sender, EventArgs e)
{
var reportParameters = (Dictionary<string, string>)Session["reportParameters"];
foreach (var item in reportParameters)
{
ReportParameter rp = new ReportParameter(item.Key, item.Value);
ReportViewer1.ServerReport.SetParameters(rp);
}
}
Anyone know why Session["reportParameters"] is null?
Or is there some other way of passing these parameters?
You can do it too:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
try
{
var js = new JavaScriptSerializer();
string reportPath= Request.QueryString["LocalReport"];
string parametersTemp = Request.QueryString["ParametersReport"];
List<ReportParameter> parameters = null;
if (parametrosTemp != "")
{
parameters = JsonConvert.DeserializeObject
<List<ReportParameter>>(parametrosTemp);
}
GenerateReport(reportPath, parameters );
}
catch (Exception ex) {
statusReport.Value = ex.Message;
}
}
}
private void GenerateReport(string reportPath, List<ReportParameter> reportParameters)
{
reportCurrent.ProcessingMode = ProcessingMode.Remote;
ServerReport serverReport = reportCurrent.ServerReport;
serverReport.ReportServerUrl =
new Uri(AppSettings.URLReportServer);
serverReport.ReportPath = reportPath;
serverReport.Refresh();
if (reportParameters != null)
{
reportCurrent.ServerReport.SetParameters(reportParameters);
}
}
Is the problem that Session["reportParameters"] is null or is it that you don't get any parameters added to your report? Because your code, as it stands, won't add parameters to your report even if you pass them across properly and so the report parameters will be null.
SetParameters takes IEnumerable<ReportParameter> (usually a List), not a ReportParameterobject. Your code should look more like this:
protected void Page_Load(object sender, EventArgs e)
{
var reportParameters = (Dictionary<string, string>)Session["reportParameters"];
List<ReportParameter> parameters = new List<ReportParameter>();
foreach (var item in reportParameters)
{
parameters.Add(new ReportParameter(item.Key, item.Value););
}
ReportViewer1.ServerReport.SetParameters(parameters);
}
I am using SendAsync to send an email. The reason I'm using async is simply to free up the UI rather than send multiple emails.
I have created the following callback event:
static void SendCompletedCallback(object sender, AsyncCompletedEventArgs e)
{
var client = sender as SmtpClient;
var message = e.UserState as MailMessage;
if (e.Error.IsNotNull())
{
if (e.Error is SmtpFailedRecipientException)
{
var status = ((SmtpFailedRecipientException)(e.Error)).StatusCode;
if (status == SmtpStatusCode.MailboxBusy ||
status == SmtpStatusCode.MailboxUnavailable ||
status == SmtpStatusCode.TransactionFailed)
{
// a new message!
}
else
{
// TODO: Log other uncaught recipient failures
}
}
else
{
// TODO: Log all other failure reasons
}
}
client.Dispose();
message.Dispose();
}
As you can see I'm attempting to catch some recipients failures. If I find such an exception I want to try and resend the email.
I'm trying to work out how to resend the email safely. I'm thinking to create a new SmtpClient rather than reuse the existing one, but to be honest, I'm fairly new to .net and I'm not so sure of the implications.
Any advice would be appreciated.
Sending email asynchronously without delaying response back to the client(UI) requires a Backgroundworker in .Net. I implemented this on my site and will share the class source code with you.
using System;
using System.Collections.Generic;
using System.Web;
using System.ComponentModel; //Background worker namespace
using System.Net.Mail;
/// <summary>
/// Summary description for ClassName
/// </summary>
///
public class postmail
{
BackgroundWorker bw = new BackgroundWorker();
string email1, subject1, message1, failedemails;
public postmail(string email, string subject, string message)
{
bw.WorkerReportsProgress = false;
bw.WorkerSupportsCancellation = false;
bw.DoWork += new DoWorkEventHandler(bw_DoWork);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
email1 = email;
subject1 = subject;
message1 = message;
}
public postmail()
{
// TODO: Complete member initialization
}
public void startsending() {
bw.RunWorkerAsync();
HttpContext.Current.Response.Buffer = true;
HttpContext.Current.Response.Flush(); // send all buffered output to client
HttpContext.Current.Response.End();
}
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
var finalemail = email1.Split(new[] { ',' }, StringSplitOptions.None);
//loop through the email addresses and send individually
for (int c = 0; c < finalemail.Length; c++) {
try
{
MailMessage mailMessage = new MailMessage();
// Sender Address
mailMessage.From = new MailAddress("emailaddress");
// Recepient Address
mailMessage.To.Add(finalemail[c].ToString());
// Subject
mailMessage.Subject = subject1.ToString();
// Body
mailMessage.Body = message1.ToString();
// format of mail message
mailMessage.IsBodyHtml = true;
// new instance of Smtpclient
SmtpClient mailSmtpClient = new SmtpClient("mail server");
//mailSmtpClient.EnableSsl = true;
mailSmtpClient.Credentials = new System.Net.NetworkCredential("emailaddress", "password");
// mail sent
Object userState = mailMessage;
mailSmtpClient.SendAsync(mailMessage, userState);
}
catch (Exception exc)
{
//fix for you
var ext = exc.ToString(); //catch exception for failed message
failedemails = failedemails + finalemail[c] + ","; //create a string of failed emails
}
}
}
private void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//called when the background process is done working
if(failedemails != null){
postmail(failedemails, subject1, message1); //resend the failed email
startsending();
}
}
}
Your concept might not be exact like mine but the key methods are:
Create an event handlers for the BackgroundWorker.
BackgroundWorker bw = new BackgroundWorker();
bw.WorkerReportsProgress = false;
bw.WorkerSupportsCancellation = false;
bw.DoWork += new DoWorkEventHandler(bw_DoWork);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
bw.RunWorkerAsync();
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
try
{
//Send your mail
}
catch (Exception exc)
{
//Catch exception here and call the resend method
}
}
private void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//do something after completion
}
The fix i made for you was to build a string of all failed addresses, then resend them after the backgroundworker is done working. cheers!!
I'm tring to add an error message to a CustomValidator by catching a potentail script attack implementing IHttpHandler im using the below method, but it just seems to kill the page as the page ends up blank, any ideas?
public override void ProcessRequest(HttpContext context)
{
try
{
base.ProcessRequest(context);
}
catch (HttpRequestValidationException ex)
{
DisplayCustomMessageInValidationSummary("< or > characters are not allowed");
}
}
private void DisplayCustomMessageInValidationSummary(string message)
{
CustomValidator CustomValidatorCtrl = new CustomValidator();
CustomValidatorCtrl.IsValid = false;
CustomValidatorCtrl.ErrorMessage = message;
this.Page.Controls.Add(CustomValidatorCtrl);
}
Thanks
Darren
i am trying to use http Module to disable textbox of each page. Here is my sample coding
public void context_OnPreRequestHandlerExecute(object sender, EventArgs args)
{
try
{
HttpApplication app = sender as HttpApplication;
if (app != null)
{
Page page = app.Context.Handler as Page;
if (page != null)
{
page.PreRender += OnPreRender;
page.PreLoad += onPreLoad;
}
}
}
catch (Exception ex)
{
throw new ApplicationException(ex.Message);
}
}
public void OnPreRender(object sender, EventArgs args)
{
Page page = sender as Page;
if (page.IsCrossPagePostBack)
{
DisableAllTextBoxes(page);
}
}
private static void DisableAllTextBoxes(Control parent)
{
foreach (Control c in parent.Controls)
{
var tb = c as Button;
if (tb != null)
{
tb.Enabled = false;
}
DisableAllTextBoxes(c);
}
}
This coding can work very well but when i use server.transer to another page. Button are not able to disable already.
For example webform1 transfer to webform2. Webform 1's button is able to disable but webform2 is not able to disable. Can anyone solve my problem?
Server.Transfer DOES NOT go through all http module pipline (thats why context_OnPreRequestHandlerExecute isn't executed for you )
you should try Server.TransferRequest or response.redirect or HttpContext.Current.RewritePath
Use LINQ to get all your textbox controls.
Don't use Server.Transfer()
Create an extension method on ControlCollection that returns an IEnumerable. That handles the recursion. Then you could use it on your page like this:
var textboxes = this.Controls.FindAll().OfType<TextBox>();
foreach (var t in textboxes)
{
t.Enabled = false;
}
...
public static class Extensions
{
public static IEnumerable<Control> FindAll(this ControlCollection collection)
{
foreach (Control item in collection)
{
yield return item;
if (item.HasControls())
{
foreach (var subItem in item.Controls.FindAll())
{
yield return subItem;
}
}
}
}
}
Taken from this answer.