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78 posts tagged with "dotnet"

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Threading and Waiting with Delegates

· 3 min read

One of the casualties of not having a full computer science education is that I was barely exposed to threading. In my two Java classes we touched upon it, and wrote some basic examples in the second semester, but that could hardly be called extensive use. Thus, a number of years on, it has been a bit of a struggle for me to use threads in a practical manner. Further complicating the matter is that I've wanted to use anonymous methods (aka delegates) and generally want to do some work after all threads have finished executing.

Passing Objects Does Not Require 'ref'

· One min read

I'm willing to admit that I made a mistake, and I share this now for your reference (no pun intended): in C#, your basic data types (int, string, short, bool) are value-types. If you want to pass them to a method and have the original value updated, instead of a copy, then you must pass them with the ref or out keywords. But not so with reference-types (hence the name!), which includes classes.

One gray area: what to do with structs. That last link says: "when a struct is passed to a method, a copy of the struct is passed, but when a class instance is passed, a reference is passed." So there you have it. Definitely pays to know the differences between C# and C++!

Do not trust the generic List!

· 3 min read

Actually, that's a slightly misleading title. You should trust List<T>, but you should also know its limitations. Here is one of the dangers of launching into using new functionality without reading all of the documentation. I've been having trouble because a client application produces thousands of reports. These reports are supposed to be sorted in a particular manner. I've been sorting and sorting in SQL, and going not paying enough attention to test well. Results in production? Not sorted.

So naturally I started properly stepping through the application, inspecting results from SQL and in code. What do I find? That SQL is returning the proper sort order, but then the ordering is getting lost. Why is that?

Performance #7: An (unsafe) Dead End

· 2 min read

This article is part of the series An Exercise in Performance Tuning in C#.Net.

After a month-long hiatus — too much work, too fast and furious for posting — I'm back to the last posts in the series on real-world performance tuning. The point of these postings hasn't been to glorify my ability to tune a C# data processing application, but rather to share what I've learned in attempts to do so.

Where to next? Turns out my next steps were false starts, at least insofar as tuning is concerned. Still, there were some lessons (or should be) from these dead ends.

AJAX RESPONSE Parsing Exception

· One min read

Problem​

In newly AJAX-enabled .Net 2.0 page, buttons that redirect user to another page are suddenly throwing the following error:

Sys.WebForms.PageRequestManagerParserErrorException: The message received from
the server could not be parsed. Common causes for this error are when the
response is modified by calls to Response.Write(), response filters, HttpModules,
or server trace is enabled. Details: Error parsing near
'<BODY><ASP_SMARTNAV_'.

Performance #6: Reading Directly Into the Parser

· 2 min read

This article is part of the series An Exercise in Performance Tuning in C#.Net.

As I look at the code I now have, I wonder if the fileLines variable is an unnecessary intermediate step. Can I rewrite so that stream.ReadLine() is passed directly into the parsing? If I do so, I'll be leaving the file open longer, but since no other application should be attempting to access the file, I'm okay with that. This means moving the open file command into MyClass.ProcessFile().

Visual Studio Says: "Failed to create component"

· 2 min read

Problem​

"Failed to create component" error pops up when dragging a custom Windows Forms control from the Toolbox onto a form. Offending line: foreach (Attribute att in Assembly.GetEntryAssembly().GetCustomAttributes(true)).

Background​

I have started building a custom DLL containing items for re-use between different Windows Forms projects. An obvious candidate is an About window. I created this as a custom control in the DLL project; the control contains a textbox, which I want to fill with the application name, the version, copyright information, and company name. All of this is to come from the AssemblyInfo.cs file, using System.Reflection where necessary:

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