I have made the Graph class, and i want to simulate a distribution network. The Graph works 100%. But, i want to use that same struct/class in all my application! For example: I have Form1 that shows the simulation, but i want to insert Nodes (for example) but i want to do it in Form2! Since the data is always in the same class, i could make my Graph instance global but C# does not take global variables. So, how would i solve this? Any ideas? Thank you!
Give the forms a reference to the Graph in their constructor.
Graph g = new Graph();
Form1 f1 = new Form1(g);
Form2 f2 = new Form2(g);
Then both forms are working with the same graph.
Make a static class. The variables that need global access, put them inside that class.
Even better idea would be to use Singleton objects to represent globally accessible objects.
Make your Graph instance a public static member of a static class and for all practical purposes you have your global.
Take a look at the Singleton pattern for one possible approach to having a common object:
C# has static fields for this. You can use SIngleton pattern in conjunction with static field. But don't forget that misusage of application-wide objects can bring down your design.
来源：https://stackoverflow.com/questions/1976066/global-variable-in-visual-c-sharp