Exchanging data between forms and solutions (added in solution explorer)

Question

Hello I am trying to send data between different forms but nothing has been working, iv tried numerous things for example

    public static class DataContainer
    {
        public static Int32 ValueToShare;
    }

   public void Form1_Method()
    {
        DataContainer.ValueToShare = 10;
    }

    public void Form2_Method()
    {
        MessageBox.Show(DataContainer.ValueToShare.ToString());
    }

anyone know how?

sorry if its a really bad question format im not the best at it

Answer 1

The following is a thread safe singleton done in C#9 or higher

public sealed class DataContainer
{
    private static readonly Lazy<DataContainer> Lazy = new(() => new DataContainer());
    public static DataContainer Instance => Lazy.Value;
    public int ValueToShare { get; set; }
}

Any project in your solution that the above class is in scope can be used as followed

Set

DataContainer.Instance.ValueToShare = 10;

Read

MessageBox.Show($"{DataContainer.Instance.ValueToShare}");

Or perhaps

int total = 9 + DataContainer.Instance.ValueToShare;

If using .NET Framework, you need to modify the int of Lazy to

private static readonly Lazy<DataContainer> Lazy = new Lazy<DataContainer>(() => new DataContainer());

Answer 2

@Alfie Chadd , If you just want to transfer a value from one form to another form, I suggest that you can define the property in the first form and use Application.Openforms method to get the value in the second form.

Here is a code example you could refer to.

Form1:

   private void button1_Click(object sender, EventArgs e)  
        {  
            Form2 form = new Form2();  
            form.Show();  
        }  
        public int ValueToShare { get; set; }  
        private void Form1_Load(object sender, EventArgs e)  
        {  
            ValueToShare = 10;  
        }  

Form2:

 private void button1_Click(object sender, EventArgs e)  
        {  
  
            Form1 form = (Form1)Application.OpenForms["Form1"];  
            MessageBox.Show(form.ValueToShare.ToString());  
        }  

When I click button1 in form1, it will show the form2. After clicking the button1 in form2, it will show the value stored in the form1.

Result:

Best Regards,
Jack

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