c#-4.0 – Make Me Engineer

the file you are trying to open is in a different format than specified by the file extension in Asp.Net

I have used CloseXML to solve the problem. public static void ExportToExcel(IEnumerable<dynamic> data, string sheetName) { XLWorkbook wb = new XLWorkbook(); var ws = wb.Worksheets.Add(sheetName); ws.Cell(2, 1).InsertTable(data); HttpContext.Current.Response.Clear(); HttpContext.Current.Response.ContentType = “application/vnd.openxmlformats-officedocument.spreadsheetml.sheet”; HttpContext.Current.Response.AddHeader(“content-disposition”, String.Format(@”attachment;filename={0}.xlsx”,sheetName.Replace(” “,”_”))); using (MemoryStream memoryStream = new MemoryStream()) { wb.SaveAs(memoryStream); memoryStream.WriteTo(HttpContext.Current.Response.OutputStream); memoryStream.Close(); } HttpContext.Current.Response.End(); } Installed ClosedXML in my project using Nuget Package … Read more

Does the System.Windows.Forms.Timer run on a different thread than the UI?

No, the timer events are raised on the UI thread. You won’t have any synchronicity problems. This is the correct version of the timer control to use in a WinForms application; it’s specifically designed to do what you’re asking. It’s implemented under the hood using a standard Windows timer. The documentation confirms this in the … Read more

Is Graphics.DrawImage too slow for bigger images?

Yes, it is too slow. I ran into this problem several years ago while developing Paint.NET (right from the start, actually, and it was rather frustrating!). Rendering performance was abysmal, as it was always proportional to the size of the bitmap and not the size of the area that it was told to redraw. That … Read more

Convert an int to bool with Json.Net [duplicate]

Ended up creating a converter: public class BoolConverter : JsonConverter { public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) { writer.WriteValue(((bool)value) ? 1 : 0); } public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) { return reader.Value.ToString() == “1”; } public override bool CanConvert(Type objectType) { return objectType == typeof(bool); } … Read more

Serialize an object to XElement and Deserialize it in memory

You can use these two extension methods to serialize and deserialize between XElement and your objects. public static XElement ToXElement<T>(this object obj) { using (var memoryStream = new MemoryStream()) { using (TextWriter streamWriter = new StreamWriter(memoryStream)) { var xmlSerializer = new XmlSerializer(typeof(T)); xmlSerializer.Serialize(streamWriter, obj); return XElement.Parse(Encoding.ASCII.GetString(memoryStream.ToArray())); } } } public static T FromXElement<T>(this XElement xElement) … Read more

Visual Studio 2010: How to enforce build order of projects in a solution?

Nick Craver mentioned checking the Configuration Manager to ensure you have the project selected to build for a given configuration. However, to set the build order for multiple projects in a solution right click the solution and choose “Project Build Order…” from the context menu.

Directly sending keystrokes to another process via hooking

This is a little code that allows you to send message to a backgrounded application. To send the “A” char for example, simply call sendKeystroke(Keys.A), and don’t forget to use namespace System.windows.forms to be able to use the Keys object. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Runtime.InteropServices; using System.Windows.Forms; namespace keybound { … Read more

Why am I getting ‘One or more types required to compile a dynamic expression cannot be found.’?

For what it’s worth, when this happened to me (in a project converted automatically from MVC2 to MVC3), all I had to do was add a project reference to Microsoft.CSharp. In my case the web.config already had the 4.0 references mentioned here, I assume courtesy of the upgrade script.

ThreadPool.QueueUserWorkItem vs Task.Factory.StartNew

If you’re going to start a long-running task with TPL, you should specify TaskCreationOptions.LongRunning, which will mean it doesn’t schedule it on the thread-pool. (EDIT: As noted in comments, this is a scheduler-specific decision, and isn’t a hard and fast guarantee, but I’d hope that any sensible production scheduler would avoid scheduling long-running tasks on … Read more

Datetime in C# add days

DateTime is immutable. That means you cannot change it’s state and have to assign the result of an operation to a variable. endDate = endDate.AddDays(addedDays);

+ More