Summary of passing values between Windows Forms

After passing values between Windows Forms, I have summarized four methods: global variables, attributes, form constructors, and delegate. The first global variable: This is the simplest. You only need to describe the variable as static. In form2, you can directly reference the variable form1,CodeAs follows: Define a static variable in form1Public StaticIntI = 9; The buttons in form2 are as follows: Private Void button#click (ObjectSender, system. eventargs E) { Textbox1.text = form1. I. tostring (); }   The second method is to use attributes. For details, see my blog: Http://blog.csdn.net/tjvictor/archive/2006/06/04/772711.aspx   The third method is to use constructor: The button of form1 is written as follows: Private Void button#click (ObjectSender, system. eventargs E) { Form2 temp =NewForm2 (9 ); Temp. Show (); }   The form2 constructor is written as follows: PublicForm2 (Int I) { Initializecomponent (); Textbox1.text = I. tostring (); }   The fourth method is to useThe delegate code is as follows: Form2 first defines a delegate Public DelegateVoidReturnvalue (IntI ); PublicReturnvalue; The code for the button in form2 is as follows: Private Void button#click (ObjectSender, system. eventargs E) { If(Returnvalue! =Null) Returnvalue (8 ); }   The buttons in form1 are as follows: Private Void button#click (ObjectSender, system. eventargs E) { Form2 temp =NewForm2 (); Temp. returnvalue =NewTemp. form2.returnvalue (showvalue ); Temp. Show (); }   Private Void showvalue (IntI) { Textbox1.text = I. tostring (); }   ClickFor button of form2, the value in textbox of form1 changes accordingly.   In the four methods, The first one is bidirectional value transfer, that is,Form1 and form2 change the I value, and the other side will also be affected. The second method can be unidirectional or bidirectional value transfer. The third method isForm1-> form2. The fourth method isForm2-> form1 one-way value transfer.   I will add a new method in the future. Another method is to useEvent, which is similar to delegate, is not mentioned here.