Learning C sharp

Quote:

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Originally Posted by dahwan

well, what do you think? i swear to god that link is safe. yust follow it and download the program.

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When you will be as old then me, then you will know how often people swear and how seldom this is true. Believe me. Never trust swears.:D

Additional: Why you dont use teh Visual Studio editor. It has an inbuilt Intellisense which keeps Typos to nearly Zero. Also it shows you missing braces and you see errors in code before compiling it as it obviously permanent is precompiling it in the background and showing you lots of info during Typing.

Re Showing Code:
As I told it to you: Simple zip the code only that means nothing in the bin file, only .cs, .resx .sup .sln .csproj files, simple only that docs needed to compile the code ourself Thas accepted in this forum. You can attach this code then in the same way as you attached the pics.

Re your project: I wonder about that mix of a console project and a WindowsApplication project. ( The message you show is in Windows Application Style. Messages in ConsoleApplications are typically on the screen only, just as your other output )

But all this is handled when you simple using the IDE instead of a Xy editor. You will get the correct namespaces you need and all that automatically simple using the IDE and its different types of projects.

And you are learning by doing this way. The IDE and its errorhandling is a teacher itself, believe me.

Quote:

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Originally Posted by JonnyPoet

precompiling it in the background

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AFAIWA, C# does not perform background compilation. Syntax errors are detected via a process very different from semantic errors.

As an example, make a new project and write a method:

Code:

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public void Foo(){
      StringBuilder sb;
      sb.Appand("hello");
      sb.Append("world");
}

---

No widdly lines, no complaints.
Now build it.
Correct the spelling error.
Build again
Correct the use of unassigned local var..

If C# did background comp, then these 2 builds would not have been necessary.. ?

Quote:

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Originally Posted by cjard

AFAIWA, C# does not perform background compilation. Syntax errors are detected via a process very different from semantic errors.

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Thats very interesting. When it doesnt backgroundcompilation how it detects so much errors during I'm typing, like missisng commas braces and lots of other things ?

In fact I dont know how it is working but when I begin typing a line I feel very comfortable, because intellisense shows me lots of things like the fields I have defined, enumerations e.g when an enumarator is needed in an code like

Code:

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if (myEnumField ==  MyEnum.AnyNumber)

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I'm starting to type if(myEnumField and it shows me MyEnum in the Intellisense.
Very practicable. Less Typos, less typing :D

Jonny Poet

lots of good stuff in here ^^
but i have a question:
In visual studio i am trying to create an application. I have a form with a richTextBox in it. Now i am trying to acces the options of it at the click of a button to change font size. Here is the code

Code:

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namespace DahWan_TextPad
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Close();
        }

        private void toolStripMenuItem2_Click(object sender, EventArgs e)
        {
            DahWan_TextPad.Form1.richTextBox1.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        }
    }
}

---

And i get the error message:

Code:

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------ Build started: Project: DahWan TextPad, Configuration: Debug Any CPU ------
C:\Windows\Microsoft.NET\Framework\v2.0.50727\Csc.exe /noconfig /nowarn:1701,1702 /errorreport:prompt /warn:4 /define:DEBUG;TRACE /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Deployment.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Drawing.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Windows.Forms.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /debug+ /debug:full /optimize- /out:"obj\Debug\DahWan TextPad.exe" /resource:obj\Debug\DahWan_TextPad.Form1.resources /resource:obj\Debug\DahWan_TextPad.Properties.Resources.resources /target:winexe Form1.cs Form1.Designer.cs Program.cs Properties\AssemblyInfo.cs Properties\Resources.Designer.cs Properties\Settings.Designer.cs
C:\Programfiler\DahWan TextPad\Form1.cs(25,13): error CS0120: An object reference is required for the nonstatic field, method, or property 'DahWan_TextPad.Form1.richTextBox1'
C:\Programfiler\DahWan TextPad\Form1.Designer.cs(181,50): (Related location)

Compile complete -- 1 errors, 0 warnings
========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped ==========

---

Why isnt the font changing?

OK, i found out of it. i needed a ":" instead of the "." at the first statement. I have a new question though. I have two forms. What code do i need in the onclick event to pop up the other form?

For a modal form, I have been doing the following:

Code:

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        private void subFormBtn_Click(object sender, EventArgs e)
        {
            using (SubForm mySubForm = new SubForm())  // initialize the subform
            {
                DialogResult myDR = mySubForm6.ShowDialog();  // show the subform
                // now I process the subform's exit code
                if (myDR == DialogResult.OK) 
                {
                    // do whatever processing I want to do if the subform exits
                    // after user pressed its "OK" button
                }
                else if (myDR == DialogResult.Cancel)
                {
                    // do whatever processing I want to do if the subform exits
                    // after user pressed its "Cancel" button
                }
            }
        }

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Modal forms don't close after they are called, they go into hiding. You either have to explicitly dispose of them, or do like I do here, open it in a "using" statement.

Quote:

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Originally Posted by msdn

When a form is displayed as a modal dialog box, clicking the Close button (the button with an X at the upper-right corner of the form) causes the form to be hidden and the DialogResult property to be set to DialogResult.Cancel. Unlike modeless forms, the Close method is not called by the .NET Framework when the user clicks the close form button of a dialog box or sets the value of the DialogResult property. Instead the form is hidden and can be shown again without creating a new instance of the dialog box. Because a form displayed as a dialog box is not closed, you must call the Dispose method of the form when the form is no longer needed by your application.

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For more info on ShowDialog, check out the msdn article on it.

thanks! Not really getting it though. i'll be looking further into it. I am having trouble adding extentions to my files though. here is the onclick for the save button

Code:

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private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            saveFile.ShowDialog();

            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                SW = File.CreateText(saveFile.FileName);

                SW.Write(txtField);

                SW.Close();
            };
        }

---

I have absolutely no idea how to add extentions, and why does the savefileDialog pop up twice?

Quote:

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Originally Posted by dahwan

thanks! Not really getting it though. i'll be looking further into it. I am having trouble adding extentions to my files though. here is the onclick for the save button

Code:

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private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            saveFile.ShowDialog();

            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                SW = File.CreateText(saveFile.FileName);

                SW.Write(txtField);

                SW.Close();
            };
        }

---

I have absolutely no idea how to add extentions, and why does the savefileDialog pop up twice?

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You're calling it twice. Get rid of the top saveFile.ShowDialog() and just leave the one in the if () test.

Working w/ file extensions is the same as working w/ strings, nothing more.

To play with file names and extentions, create a large multiline textbox on your form (here called textBox1), and a button that does this:

Code:

---

        private void button3_Click(object sender, EventArgs e)
        {
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                string fNameAndExt = saveFileDialog1.FileName;
                textBox1.Text = "file & ext name: \t\t" + fNameAndExt + Environment.NewLine;

                int indexOfPeriod = fNameAndExt.IndexOf('.');
                string fName = fNameAndExt.Substring(0, indexOfPeriod);
                string fExt = fNameAndExt.Substring(indexOfPeriod + 1);

                textBox1.Text += "file name: \t\t" + fName + Environment.NewLine;
                textBox1.Text += "extention: \t\t" + fExt + Environment.NewLine;

                string fNameNewExt = fName + ".foo";
                textBox1.Text += "fileName with new extention: \t" + fNameNewExt;

            }
            saveFileDialog1.Dispose();
        }

---

Please get back to me to let me know if this does or doesn't make sense.

good luck!

/Pete

Oh... right ^^' i didnt know the one in the "if" actually called it..

Quote:

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Originally Posted by Petes123

To play with file names and extentions, create a large multiline textbox on your form (here called textBox1), and a button that does this:

Code:

Code:

---

        private void button3_Click(object sender, EventArgs e)
        {
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                string fNameAndExt = saveFileDialog1.FileName;
                textBox1.Text = "file & ext name: \t\t" + fNameAndExt + Environment.NewLine;

                int indexOfPeriod = fNameAndExt.IndexOf('.');
                string fName = fNameAndExt.Substring(0, indexOfPeriod);
                string fExt = fNameAndExt.Substring(indexOfPeriod + 1);

                textBox1.Text += "file name: \t\t" + fName + Environment.NewLine;
                textBox1.Text += "extention: \t\t" + fExt + Environment.NewLine;

                string fNameNewExt = fName + ".foo";
                textBox1.Text += "fileName with new extention: \t" + fNameNewExt;

            }
            saveFileDialog1.Dispose();
        }

---

Please get back to me to let me know if this does or doesn't make sense.

good luck!

/Pete

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Um... what? =S

Quote:

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Originally Posted by JonnyPoet

Thats very interesting. When it doesnt backgroundcompilation how it detects so much errors during I'm typing, like missisng commas braces and lots of other things ?

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That's syntactical analysis, probably from building an abstract syntax tree (part of the process of compilation)
It is very different to semantic analysis, which looks at the meaning of things

As an example, see this sentence:

"You one those of got have."

All words are spelled correctly, the sentence starts with a capital letter and finishes witha full stop. It is syntactially correct and I could ask a person who doesnt know any english at all, to verify that this sentence is correct according to rules

Now give the sentence to an english person and they will say it doesnt make sense, because it doesnt.. The words are in the wrong order.. It's semantically incorrect

FYI: The other feature of language (that doesnt crop up in programming much) is pragmatics - the meaning within a context. The correct sentence "You have got one of those" can be taken two ways depending on the stress:
"YOU HAVE got one of those" -acknowledgement that you've seen e.g. a bag in a shop, that the person you are with already owns.. i.e. "Hey, that's the same bag as you own"
"You have GOT one of those" - telling the third person off for looking at something they already have i.e. "You already have one of those, youre not having another"

Heh, so, brief English lesson over.. C# checks your syntax, not your semantics.

Quote:

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In fact I dont know how it is working but when I begin typing a line I feel very comfortable, because intellisense shows me lots of things like the fields I have defined, enumerations e.g when an enumarator is needed in an code like

Code:

---

if (myEnumField ==  MyEnum.AnyNumber)

---

I'm starting to type if(myEnumField and it shows me MyEnum in the Intellisense.
Very practicable. Less Typos, less typing :D

Jonny Poet

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Intellisense is very different to syntax checking or background compilation. UltraEdit32 for example, is just a text editor, with a word list. It knows nothing of languages or objects. ALl it knows is that when you type someKeyWord. then it has to show a menu of members of someKeyWord.. As noted this doesnt require any compilation, and such an index can be constructed entirely from the documentation

Quote:

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Originally Posted by cjard

That's syntactical analysis, ...

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very good explanation also for those who doesn't have english as mothertounge like me. ;)

i am having trouble accessing some stuff again. i cant get to the lbl where ever i put it. "The name "lbl" does not exist in the current context"

Code:

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using System;
using System.Drawing;
using System.Windows.Forms;

class cDialog: Form
{
        static void Main()
        {
                Application.Run(new cDialog());
        }
       
        cDialog()
        {
                this.Text                =        "Calculator";
                this.Size                =        new Size(200,200);
               
                Button b1                =        new Button();
                b1.Size                        =        new Size(35,25);
                b1.Parent                =        this;
                b1.Text                        =        "Text";
                b1.Location                =        new Point(10, 10);
                b1.Click          +=        new EventHandler(click_b1);
               
                label();
        }
       
        void label()
        {
                Label lbl                =        new Label();
                lbl.Text                =        "You clicked the button =P";
                lbl.Location        =        new Point(10,40);
        }
       
        public void click_b1(object sender, EventArgs e)
        {
                cDialog:label(lbl.Parent = this);
        }
}

---

Quote:

---

Originally Posted by dahwan

i am having trouble accessing some stuff again. i cant get to the lbl where ever i put it. "The name "lbl" does not exist in the current context"

Code:

---

using System;
using System.Drawing;
using System.Windows.Forms;
 
class cDialog: Form
{
   static void Main()
        {
                Application.Run(new cDialog());
        }
  private Label lbl = null;
        cDialog()
        {
                this.Text                =        "Calculator";
                this.Size                =        new Size(200,200);
 
                Button b1                =        new Button();
                b1.Size                        =        new Size(35,25);
                b1.Parent                =        this;
                b1.Text                        =        "Text";
                b1.Location                =        new Point(10, 10);
                b1.Click        +=        new EventHandler(click_b1);
 
          //label();
        }
 
        void label()
        {
                Label lbl                =        new Label();
                lbl.Text                =        "You clicked the button =P";
          lbl.AutoSize  = true;
                lbl.Location        =        new Point(50,50);
                this.Controls.Add(lbl);
        }
 
        public void click_b1(object sender, EventArgs e)
        {
                //cDialog:label(lbl.Parent = this);
          label();
        }
}

---

---

I'm Sorry I have never seen the Main Function within the form class, it works but normally I would use program.cs to start the application. Open a new Project and create it automatically with the wizzard as a standard windows Application and you will see how this normally is done.
You need to have lbl as a private member of the form or you cannot access it in the way you wanted it. When you only have a local variable in a function 'label' then this is created on the stack and destroyed when leaving the function. So you got the compiler error.
You need to have Autosize or to define the size of the label otherwise its maybe deformatted. Also you need to add the lbl to the forms Controls, or you cannot see it on the form.

I'm missing the dispose methode for this form too !
Do a Dummy Application as i told you and look wht the designer is creating for you also look into the form1.designer.cs

Take a good book like MS Visual C#2005 Step by step and read it. It will help you on your fist steps a lot.

i dont use VS, and i dont want to use it. i want to be able to create my own programs, not someone to do it for me.
But you didnt tell my why that program wont work. Thats kind of the problem here...