In the form programming of C, I want to define variables in one phase window and call them in anothe

That's it, this belongs to the parameter transfer between forms, there are many ways!

One of them. a window.

in a: window public string publicstring;

b window. Call a

a a=new a();

Custom becomes two";;

1) In the background generation of form3.

Code 2) In form1, suppose you click button1 to display form3, backend**.

When do you want the textbox in form3 to show the value of the textbox in form1?

Set a variable as a global variable in form A assumes public static string a;

Assign a value to the value change event of the control: a=name of the control. text；

Because a is a static global variable, it can be accessed directly when the b form uses the value of a; As for whether it is an assignment or a substitution operation, it can be obtained.

It's easy.

**As follows: Suppose the definition of the variable in form1 is: public string form1str="form1";

In form2: form1 myform1 = new form1();

string form2str = ;

This will allow you to get a reference to the variable in form1!

However, it is not recommended to use it this way, you can use attributes to do it.

**As follows: in form1: private string form1str;

public string form1strset

** similar in form2: form1 myform1 = new form1();

string form2str = ;

This is in line with the principle of object-oriented encapsulation!

When two windows are related:

from2 f = new from2();

f.variable = variable of f1;

Then you can use it in form2.

Either public static

Define this variable as public static string;

Then use form1 in form2this variable.

OK. The simple method, as the ls2 bit says, is to declare static variables in the first form and then use them directly in the second form.

However, this static is okay if it is less, and it is best to use the commission if there are many things to be saved.

Yes! Define the variable with the public static modifier: public static string txt="";

txt=;

For example, if form A wants to call the value of a textbox in form B, define a public static variable in form B, the type is string, and the variable name is str, which is used to store the value in the textbox, so that in form A, it can be directly used to call the value of its textbox.

Can be in addition to the ground floor method; You can also define a property get, set

Set the modifiers property of control 1 in form 1 to public, and form 2 can access this control, which is private by default.

Yes, you can create a new class file in your project, and then define a static variable in that file, for example, in the class file (.).CS file), I'll take int as an example, public static int i="";Note that you must add public.

Then you can call the assignment in form2, you can assign the value of the global variable after changing the value to i (, and then call i in form1.

The other window must first have a variable that points to the window, and then the variables of the window are used to access the variables under the instance of this window.

Oh, and by the way, the access to the target window variable should be public.

If you need to call it, just add a public method to the form1 window and call it in form2. For example:

public void plusnumber(int number)form2 can be used directly:;

You just need to write a public method in form2 to commit the data, and then call it in form1?

If you call another window's control directly, it can cause thread-safety issues, which is best achieved using a delegate.

1. Define it as a global static variable that can be called directly in other forms, and there is no need to pass the form:

Definition: public static datatable mytable=new datatable("datacurrent");

Call: 2, put it directly into the constructor of the form and pass it to the new form, such as the form2:

Constructor for the new form: public form2(datatable dt).

Get an instance of the new form: form2 form=new form2(mytable);

I hope it helps, and if you have any questions, please ask or hi

Since this variable is local, you need to set it to global in order to call it, outside of the method.

If you want to call the variables in form1 in form2, then you need to pass form1 as an argument when you open form2, and then you can call the global variables in form1

In the click event in form1, write the following **::

private void button1_click(object sender, eventargs e)

in form2.

form1 owner = (form1);

To get mytable through the owner, and importantly, change the access modifier of mytable to protected or public!