C# 我如何学习在另一个 Class 中调用我的方法的 Class

Question

public class Form1:Form
{

     public Form1()
     {

     }
     Form1_Load(object Sender,EventArgs e)
     {
           SampleClass Sample=new SampleClass();
           Sample.MyMethod();
     }
}

this is first class in my project and second is

Hi All

public class SampleClass
   {
       public void MyMethod()
       {
          //When Form1 or another class call this Method
          //I want to know it for example

         Caller.Title="Deneme";
          //
         //Unless send parametr.How Can I learn Caller class and i change it items?

       }
   }

Answer 1

The caller will have to pass a reference to itself into the method.

   public void MyMethod(Form caller)
   {
     caller.Title="Deneme";
   }

Or if you don't want the SampleClass to have a strong link to the Form class - it may be in a separate assembly that doesnt reference Windows form, you could pass in an Action that gets called with the correct string passed in.

 Form1_Load(object Sender,EventArgs e)
 {
       SampleClass Sample=new SampleClass();
       Sample.MyMethod( title => this.Title = title );
 }

and

   public void MyMethod(Action<string> setTitle )
   {
     setTitle ("Deneme");
   }

---

Edit to explain delegates

The Action parameter

The Action parameter on MyMethod is essentially a variable that contains code that can be run. (It does take a little head twisting to fully understand the concept.) The <string> part of the type says that we can pass in a string to this code that is going to be run.

Then the line that goes

 setTitle ("Deneme");

is calling this code and passing it the text "Deneme". This is the text that you want to set the Windows title to be. Now, the MyMethod method actually doesnt know that it is going to be setting the Windows title to be this text. This has become the responsibility of the caller. (If you want MyMethod to be absolutely certain that it is setting the Title of a Form, then the first solution is the one that you want.)

Calling

The caller of the method calls

MyMethod( title => this.Title = title );

The parameter to MyMethod is:

title => this.Title = title

This is the code that you are passing to the Action variable. The title to the left of the => is the variable that will have the String that is passed to it when the code is invoked, and the stuff to the right of the => is the code that gets called.

So when the form calls MyMethod, it is saying I want that string and I'm going to set my title to it.

The beauty of this is that MyMethod doesn't know about the form. If you want to reuse your class when you write a Console application, you may call:

MyMethod ( title => Console.WriteLine (title) );

MyMethod doesn't need to be touched at all!

Answer 2

You could try:

public class SampleClass
{
    public void MyMethod(Form sender)
    {
        sender.Text = "title";
    }
}