wpf - Making instances of forms public C# -

i attempting pass information child form parent. have been using following code found on forum me:

form1.cs

using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.text; using system.windows.forms;  namespace childform { public partial class form1 : form {     public form1()     {         initializecomponent();     }      private void button1_click(object sender, eventargs e)     {         form2 tempdialog = new form2(this);         tempdialog.showdialog();     }      public void msgme()     {         messagebox.show("parent function called");     }  } } 

form2.cs

using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.text; using system.windows.forms;  namespace childform { public partial class form2 : form {     private form1 m_parent;      public form2(form1 frm1)     {         initializecomponent();         m_parent = frm1;     }      private void button1_click(object sender, eventargs e)     {         m_parent.msgme();     } } } 

which works , , good. trouble is, program requires me set variables within tempdialog, form 1, in methods other button1_click. but, these cannot find instance of tempdialog because in button1_click.

also, cannot move out of method (say, class) because 'this' modifier not reference form1...

any ideas how can reference form1 form2 , vice versa? using code or otherwise?

thanks

i'm not sure mean last comment this. make field references form2 , initialize in constructor. can reference _form2 in other methods of form1.

public partial class form1 : form {     private form2 _form2;     public form1()     {         initializecomponent();         _form2 = new form2(this);     }      private void button1_click(object sender, eventargs e)     {         _form2.showdialog();     }  } 

this sort of thing can difficult follow, when complexity increases. better way might make form1 , form2 have references common object can both manipulate.