[superkb10]

I'm a bit new to C# Window Forms Applications. Anyway, I'm writing a basic calculator program to start off. I'm making a button for deleting from the number, I tried doing

TextBox.Text.Length -= 1;

But an error message said that

 TextBox.Text.Length 

was read only or something like that. Any ideas on how I can have something like a backspace event?

It would be greatly appreciated

[Kilorn]

Backspaces work natively for Textboxes. Are your textboxes not working when you hit the backspace key?

[Atli]

The Text property is just a string, so you could manipulate it like any other string. Look into the Substring and Remove methods.

This post has been edited by Atli: 02 February 2012 - 07:49 PM
Reason for edit:: Meant to write Remove, not Replace.

[superkb10]

No, the backspace works, I would just like to have a delete key so that people using it could use either the keyboard or the calculator keypad.

And Atli, did you mean Remove? That's where your link leads to. Anyway, I tried this:

TextBox.Text.Remove(1);

But to no avail. Normally the removing length should work with strings, I don't know why it doesn't work with this.

This post has been edited by superkb10: 02 February 2012 - 07:07 PM

[tlhIn`toq]

He's saying get the .Text of the textbox

Now set it to a substring of itself, for its own length - 1

myTextbox.Text = myTextbox.Text.Substring(myTextbox.Text.Length-1);

.Length for the text is mostly a read-only property. It isn't smart enough to know *how* to reduce it.

So if the text is "yogi" the .Length is 4. But setting the length to 3 won't make it delete the last 'i' character.

rookieWhat this shows us is that you aren't familiar with breakpoints and how to debug your own code.Learning to debug one's own code is an essential skill. Sadly, one that apparently no college course teaches. Silly if you ask me.

Placing breakpoints and walking through the code line by line allows you to actually WATCH it execute. Visualizing what your code does will let you see why it behaves the way it does.

It would be well worth your time to do the tutorials on FAQ 2. A couple hours learning this skill will save you hundreds of hours of confusion in one project alone.

Also, see FAQ 23 below


TOP most asked:
What does this error message mean?
FAQ 2: How do I debug
FAQ 3: How do I make Form1 talk to Form2

---

FAQ (Frequently Asked Questions - Updated Jan 2012

---

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  Quote

  ]
  I've tried going through those, the only way im learning is through struggling to write code from scratch, the thought process i guess is helping me, i've tried reading sooo much and watching videos but honestly im not learning until i actaully type it.

  
  
  I hear this a lot and the only thing I can think is students are buying the wrong books. Or they read the information and don't feel they need to actually work the lessons/exercises. This argument sounds like there are only two choices:
  

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  • Just read C# dictionaries.

  
  
  Maybe this is from students buying the course textbook and reading it on their own, without the benefit of the teacher and their lesson plan and exercise assignments. When one mis-uses the materials, or only has 25% of the materials, of course they won't learn.
  
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  Obviously you didn't read the resources list I posted or get any one of the NUMEROUS self-teaching books.
  
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  Quote

  would i be able to take out the private double[] months = new double[12];
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  A:
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  You are asking a very vague, generalize question about a broad topic.
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  DIC Tutorials Section
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  • Host Operating System - 16gig, quadcore, 3x24" Dell LCDs at 1920x1200 (2 landscape, 1 portrait)
    
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    • Device Drivers
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      • Take a snapshot of the VM machine for easy restoration

  
  
  That is my entire install
  
  
  
  
  
  
  
  
  Working for myself/Deploying/Selling software:
  
  
• Q:How do I stay a free lance coder for a living?
  A:http://justcreatived...eelancing-life/
  
  
• Q: How do I become a better coder?
  Read this, and practice a lot.
  How to be a better coder
  
  
• Q: Are there any resources for small C# projects a novice to become a better coder?
  A:
  Spoiler

  There is a novice projects thread here on DIC. But here's my advice whenever this comes up:
  
  Look around. Anyone who can't find a dozen projects a day by just walking through life, is doing so with their eyes closed to the world.
  

  • Do you like the weather? What about a program to get the various weather reports from different web sites? Or to integrate with one of the numerous USB weather station hobby kits on the market?
    
  • Do you like the run? What about a program to log your runs, routes and progress?
    
  • Do you like movies? What about a program to catalog all your DVD's and AVI's?
    
  • Do you like photography? What about a program to browse your images, assign tags and GPS?
    
  • Do you like shooting? What about a program to track your aim and improvement?
    
  • What about every time you walk into a business and someone says "Oh, I'm sorry. The computers are slow/suck. This is going to take 10 minutes and 25 screens." Sounds like an opportunity to make and maybe even sell them a new program. So go home and make it first before you open your mouth. If you succeed in something great. If you fail, then you know where to study more and you haven't embarrassed yourself.

  
  
  What about every time you walk into a business and someone says "Oh, I'm sorry. The computers are slow/suck. This is going to take 10 minutes and 25 screens." Sounds like an opportunity to make and maybe even sell them a new program. So go home and make it first before you open your mouth.
  
  If you succeed in something great. If you fail, then you know where to study more and you haven't embarrassed yourself.
  
  Go to any of the on-line coder for hire sites. Read the new contract descriptions. DON'T BID ON THEM. Just read them. This will tell you what is requested by employers so you know where you have the potential to make money, and tell you where you should study. Then pick a project and build it. TRACK YOUR TIME. If you don't know how long it takes you to build a project then you won't be able to bid on contracts. If you bid $50 for 50 hours of work you're going to starve to death. Again, building projects just to learn the technology and learn your own speed and weaknesses is something we all do/did and you need to do too. Once you can build a project just for the learning experience, fast enough that you could have made a competitive bid... Now you can start considering actually bidding on new contracts that are in your skill set.
  
  
  
  
• Q: How do I sell the software I've developed?
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• Q: How do I decide how much to charge for my application?
  A: Read this
  
  
• Q: How do I deploy my program / Make an installer?
  A: C# application deployment project
  Include the smallest .NET possible

[AdamSpeight2008]

The type String in .net is immutable.
Which means when you do an operation on them, it creates a new instance of the type string. So if you want to affect the original, you need to change the reference to the contents.

string modifiedstr = mystring.substring(0, mystring.lenght-1)
mystring = modifiedstr

[superkb10]

Okay, AdamSeight2008

I took your suggestion, however, my problems is it's deleting only the first character in it. I am looking for more of a backspace type thing.

[tlhIn`toq]

If you would just take a moment to read the MSDN on strings rather than asking others to do your research for you, you would see there is an overload for substring that takes a starting point and length.

http://msdn.microsof...y/aka44szs.aspx

This page also explains why the way you were shown (be me included) was wrong and acting as a first character delete instead of a last character delete.

[superkb10]

Okay, well I figured it out(kinda), I guess you have to make 0 the StartIndex. I was thinking that if I put in no value, and just had one parameter, the default value for where it starts would be 0, but guess not.

[AdamSpeight2008]

How would it know? that was your intent?
It's only since C#4.0, that the C# language could express optional parameters,and thus default parameters values. The only way available to developers was method overloads, and comes with restrictions on what's possible.
Overload need
to have different input types
or different number of parameters.
or a mixture of both.

It can't have methods with the same name, that take the same input parameters (it signature) and do different things. It can't even do overloads with different return types.

Reading the Documentation of the API, is essential to know what the API does.

This post has been edited by AdamSpeight2008: 02 February 2012 - 08:30 PM