954,178 Members — Technology Publication meets Social Media
Username:
Password:
Lost login information?
Have something to say? Contribute New Article Reply to this Article

Cannot Test For Condition

I'm developing a practice program that simply converts a temperature value from fahrenheit to celsius when the user enters an integer, selects a radio button and then clicks a button.

I'm having trouble testing if the user has selected a radio button. In the click event method for the calculate button, an if statement tests if the text box is empty and displays a message in a result label if it is (this works). If there is a valid entry, then a second if statement checks if neither of the radio buttons is checked, and if that is the case, it should display a message to that effect in the result label. This is not working.

If no radio button is selected, the program does nothing. Here's the code:

if (textBox.Text == "")
   labelResult = "Please enter a temperature to convert.";
else
   if ((radiobutton1.Checked == false) && (radiobutton.Checked == false)
      labelResult = "Please select a conversion type to perform":
   else
      calculateMethod();


The code compiles, but again, it's as if the second condition is not being tested. I can't tell if the problem is with the second "if" expression, or of the code block is not written correctly. I could just set one of the radio buttons to be automatically selected when the program runs, but I thinkI may need to perform this kind of task in another, future situation, so I want to know what I'm doing/not doing.

Any ideas?

Toulinwoek
Posting Whiz in Training
274 posts since Mar 2005
Reputation Points: 10
Solved Threads: 2
 

try this:

if (textBox.Text == "")
   labelResult = "Please enter a temperature to convert.";
else{
   if (!radiobutton1.Checked && !radiobutton.Checked)
      labelResult = "Please select a conversion type to perform";
   else
      calculateMethod();
}
campkev
Posting Pro in Training
484 posts since Jul 2005
Reputation Points: 14
Solved Threads: 19
 

Awesome! That worked.

I didn't know I could use the "not" operator (!) in that kind of situation. That simplifies a lot of things I had been thinking about for some other concepts.

Also, after studyng this code, I think can see why the second "if-else" statements needed to be bracketed. The example in the book I'm studying with was using recursive "if" statements to test the same condition against multiple possibilities; in this case, I'm testing two different conditions. Am I understanding this correctly?

At any rate, thanks for the solution. I guess I was trying to make it more complex than it needed to be.

Toulinwoek
Posting Whiz in Training
274 posts since Mar 2005
Reputation Points: 10
Solved Threads: 2
 

actually, I'm not 100% sure what was wrong with it the 1st time. it shouldn't even compile the way you had it listed.

campkev
Posting Pro in Training
484 posts since Jul 2005
Reputation Points: 14
Solved Threads: 19
 

This article has been dead for over three months

Post: Markdown Syntax: Formatting Help
You