sharing values between forms

Question

I am a begining C# programmer using Visual Studio 2005 Beta and have the following question.

How can I access values from common controls, like a ComboBox, or variables within Form1 (the parent) from Form2 (a dialog) and vice versa?

Scenario:
In Form 1 the User enters form data.
In Form 2 the input data is processed and the results are displayed in a new form
with readonly textboxes.

An explanation plus a code snipplet would be apreciated.

Nschan · Answer

In windows programming it is ok for a parent window to access a child/secondary window. But typically having the child/secondary window access the parent directly is not a good idea. It creates a double dependency (class 1 depends on class 2 and class 2 depends on class 1) that makes it hard to reuse the child/secondary window in other situations. Below is a simple example of a parent form that opens up a secondary results dialog: class ParentForm { ... private void showResults_Click(object sender EventArgs e) { // 1. Create an instance of the results dialog. ResultsForm dlg = new ResultsForm(); // 2. Copy necessary input data TO the results dialog. dlg.InputValue = Int32.Parse(this.inputValueTextBox.Text); // 3. Show the results dialog. if ( dlg.ShowDialog() == DialogResult.OK ) { // 4. Optionally copy back any modified values FROM the results dialog. this.outputValueTextBox.Text = dlg.OutputValue.ToString(); } } }