C#: «How i can do it» for English-speaking visitors

This is little a «Questions-Answer» node for my international visitors. Hope you find your answer here…

P.s. Sorry for my English =)

Question: How to stop thread?
Answer: There are two way to stop thread. First is aborting.

Thread t = new Thread(function);
t.Start();
t.Abort(); //Stoping the thread

Second way — using some flag. Example:

bool flag = false;
void function() {
 while (!flag) {
   MessageBox.Show("Message!"); 
   Thread.Sleep(2000);
 }
}

If you set variable ‘flag’ to ‘true’ — the thread will be exit.

Question: How to convert string to int?
Answer:

string s = "123";
int i = Int32.Parse(s);

Question: How to create file or folder?
Answer:

//Directory
System.IO.Directory.CreateDirectory("MyDirName");
//File
////Work with bytes
System.IO.FileStream fs = System.IO.File.Create("FileName");
////Work with text
///////Read
System.IO.StreamReader sr = System.IO.StreamReader("FileName");
///////Write
System.IO.StreamWriter sw = System.IO.StreamWriter("FileName");

Question: What is ‘get’ and ‘set’ keywords?
Answer: You can use keywords ‘get’ and ‘set’ to protect element of your class. You can disable modification of class element, or disable reading element. Example:

class Test {
   private int _a = 5;
   private int _b = 5;
   private int _c = 5;
   public int d = 5;

   public int a { get { return this._a; } }
   public int b { set { this._b = value; } }
   public int c { set { this._c = value; } get { return this._c; } }
}
///
Test t = new Test();
t.a = 1; //error
int temp = t.a; //ok
t.b = 1; //ok
temp = t.b; //error
t.c = 1; //ok
temp = t.c; //ok
t.d = 1; //ok
temp = t.d; //ok

Question: How to clone object?
Answer:

Button b = new Button();
Button clone = (Button)b.Clone();

Question: How create event?
Answer: Events — it’s functions. To create event in your class you can use this code:

class T
{
   int A = 1;
   public delegate void _AChangeEvent();
   public event _AChangeEvent AChangeEvent;

   public void setA(int A)
   {
     this.A = A;
     this.AChangeEvent();
   }
}
/////in main class, onLoad event
T t = new T();
t.AChangeEvent += new T._AChangeEvent(t_AChangeEvent);
t.setA(2);
/////in main class
void t_AChangeEvent()
{
   //Show message when function 't.setA' was call 
   MessageBox.Show("'A' was changed!");
}

Question: How to change current directory (location)?
Answer: To change current directory use class ‘Environment’.

Environment.CurrentDirectory = "C:\\";

Question: How to read file line by line?
Answer: To read all file by line you need use ‘while’ loop.

System.IO.StreamReader sr = new System.IO.StreamReader("filename");
string line = String.Empty;
while ((line = sr.ReadLine()) != null)
{
  MessageBox.Show("Current line: " + line);
}

Question: How show form modal?
Answer: You need create new windows form class to your project (for example with name ‘Form2’) and use this code:

Form2 f2 = new Form2();
f2.Show(); //Show not modal form
f2.ShowDialog(); //Show modal form

Question: How do something every second?
Answer: If you need do some code with some interval use this code:

System.Windows.Forms.Timer t = new System.Windows.Forms.Timer();
t.Interval = 2 * 1000; //every two seconds
t.Tick += new EventHandler(t_Tick);
//t.Enabled = false; //Stop timer
t.Enabled = true; //Start timer
//////////
void t_Tick(object sender, EventArgs e)
{
  MessageBox.Show("This message show every two seconds!");
}

Also… You can use ‘google tranclate’ to view my site in your language and try find more answers on questions. Same if you have a question, feel free to contact me. I try to help you. Thanks!