Saturday, 4 February 2012

relationship between pixels

A pixel is a point is a dot. When it comes to rendering on screen, what matters is scale: As long as everything is in scale, elements can be whatever "resolution" you want. Full discussion: http://dougv.us/6m

Ask me anything

Wednesday, 1 February 2012

what are the zip codes near 95014 with in 50 miles

Um … just use my demo to find out. http://dougv.us/oj

Ask me anything

Monday, 9 January 2012

Your tutorial "Multilingual Web Pages Via PHP, Arrays And MySQL" is really very useful for me.So, thanks.I just want to ask a question,in your tutorial to exampled three languages’en,fr,sp’ but i want to add more than three languages.Is it possible?

Sure. The methodology works for any number of languages; just make the right number of keys and keep the translations in order.

Ask me anything

Sunday, 1 January 2012

Tumblr Mangles Developer Relations

Last week I logged on to Tumblr and was confronted with this abomination:

missing e notice from tumblr

Missing e notice from tumblr. Way to encourage API development, guys.

Needless to say, this is pretty disturbing, and I wonder what Tumblr is thinking by posting this.

Continue reading: Tumblr Mangles Developer Relations »

Sunday, 25 December 2011

Parent-Child DropDownList Controls In ASP.NET Web Forms (VB.NET)

Some time ago I promised a formspring anon I would do a tutorial on parent / child DropDownList controls in ASP.NET Web Forms. At long last, I’m delivering. (From here on out, I will use “DropDownList” and “select list” interchangeably.)

Parent-child DropDownList controls means you have a parent, or main / master select list. Based on whatever selection is made in that first DropDownList, a second, “child” or “detail” select list is populated with relevant results.For example, if we had a database of cars, we might have a parent (master) DropDownList of manufacturers — Ford, Chevy, Toyota, etc. — and populate the child DropDownList with models from the selected manufacturer. So, if someone chose Ford in the parent select list, the child select list would automatically populate with choices such as Fusion, Mustang, Explorer, F-150, etc.

I’ll be demonstrating two different ways to accomplish this task, as well as a few variations on the first: First, binding with only SqlDataSource controls, which is by far the easiest way to proceed and will suffice for about 90 percent of applications; second, using code behind and CompareValidator controls, to cover all possible roadblocks.

Some notes before we proceed:

  • I’ll use the ZIP Code database I’ve been using for a while as the back-end data. I also have a separate table of USPS state codes I’m using as the parent data, to help illustrate that you can use several tables / data sources to fuel this solution, provided the keys that relate the data make sense to each data store. In other words, you can use a lot of different sources for your data, so long as the data is relational.
  • I’m going to use SQL Server, stored procedures and a connection string stored in my web.config file to access my data. I recognize that some people prefer to use SQL statements / LINQ and the like, or can only use Access / MySQL or other data stores. I really urge you to always use stored procedures, as they are way safer than inline SQL statements. As far as alternative data stores go, that should be a easy a fix as switching your code to use to the relevant ADO.NET ODBC classes, rather than the SQL Client classes.
  • This solution should work for ASP.NET versions 2.0 forward.

Continue reading: Parent-Child DropDownList Controls In ASP.NET Web Forms (VB.NET) »