?
Solved

Casting woes from System.Single directly to System.Double

Posted on 2004-10-14
2
Medium Priority
?
236 Views
Last Modified: 2010-04-15
I am reading from a SQL table whith a row "open" of type "float" (which C# / .NET reads as a System.Single value).

Here is the code:
1. Console.WriteLine("Value: {0}, data type={1}", myReader["open"], myReader["open"].GetType());
2. float f = (float)(myReader["open"]);
3. d = (double)f;
4. d = (double)(myReader["open"]);

1. prints: Value: 24.02, data type=System.Single
2. No problem (f=24.02)
3. No problem (d=24.02)
4. Exception - invalid cast ...

Why? How is statement 4 different than 2 & 3 combined? Does C# have trouble doing the conversion directly, and if so, what would be an elegant and robust way to do it?

Thanks,
Patrick
0
Comment
Question by:patrickq
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
2 Comments
 
LVL 3

Expert Comment

by:aacool
ID: 12322363
Please see my code below - this works fine - no exceptions are thrown.
   try
   {
         System.Single single = 5.3F;
         float f= (float)single;
         double d1 = (double)f;
         double d2 = (double)single; // no exception thrown.
   }
   catch(Exception ex)
   {
      MessageBox.Show(ex.Message+ex.StackTrace);
   }



Not sure what exactly is the issue without looking at the definition of myReader. Could you post the exception thrown?
0
 
LVL 3

Accepted Solution

by:
aacool earned 150 total points
ID: 12352370
Did this work out for you?
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article introduced a TextBox that supports transparent background.   Introduction TextBox is the most widely used control component in GUI design. Most GUI controls do not support transparent background and more or less do not have the…
Performance in games development is paramount: every microsecond counts to be able to do everything in less than 33ms (aiming at 16ms). C# foreach statement is one of the worst performance killers, and here I explain why.
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…
Suggested Courses
Course of the Month11 days, 12 hours left to enroll

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question