Error in references

Question

HI! I try to run diferent examples but get errors with some of the references. Like a yellow tag in the references on some of 'em like the System.Configuration I guess there some dll's missing but where can i find 'em`? using System.net I try to do something like getting an IPAddress. There is nothing called system.net in add references. I'm new to C# so please help? Yepp

Answer 1

Dear Null and Character String cant Add by this way if you want to add numeric then you should do like this


TextBox3.Text = (Convert.ToDouble(Convert.ToString(textBox1.Text)) + Convert.ToDouble(Convert.ToString(textBox2.Text))).ToString();

in Text Change Event

it will convert zero if null exist



you can also chaeck by TextBox1.TextLenght  = 0  then zero value

Answer 2

Yes, It would raise error as you are trying to add "" (empty text) with your 2/3 texbox's values(integer).

Just initialize (default Text value) all your textboxes with 0 or 0.00

So, no matter how many inputs you give, it will not give you error. 

Answer 3

hello there 

it is a windows application now i am attaching my whole project in this project i am doing five addition and get and get five output at a click but is i only want to do only 2 addition and the remaining textbox left emty then the programme is showing error THAT """Input string was not in a correct format."""""  

please help me to ignore the remaining textbox 

Answer 4

Is it a Win or Web application? And what kind of error are you getting? How are you implementing your logic? 
Please provide more details to resolve your problem.