复选框。选中的其他表单上的更新

Question

I have 2 forms, UserInterface and Client I'm passing checkbox2.Checked info to Client but it only works however it was at launch. When I tick or untick and close and reopen Client it wont notice the change.

Modifiers is Public on checkbox2 at UserInterface form.

Here is Client code:

public partial class Client : Form
{
    private UserInterface ui1;

    public Client()
    {
        InitializeComponent();
    }
    public void CheckBoxCheck()
    {
        if (ui1.checkBox2.Checked == true)
        {
            MessageBox.Show("true");
        }
        else
        {
            MessageBox.Show("false");
        }
    }
}

If the checkbox is ticked at launch Client will show "true" but if I click it (untick) and run Client it will still show "true".

What do I need to add or modify so checkbox2 will be updated in realtime. Thank you.

Note: I'm pretty new with coding, explanations are appreciated.

Answer 1

Your Forms should be connected. It looks like ui1 is a different instance of UserInterface form.

There are different approaches to pass the data between forms and it depends on your demands.

For instance you could create UserInterface form inside of Client. And use the Show() method to show it.

Answer 2

You should probably be making use of the Checkbox.Checked event inside UserInterface class and then fire a custom event that your Client can subscribe to.

public event EventHandler<EventArgs> CheckboxCheckedChanged;
protected void OnCheckboxCheckedChanged(EventArgs e)
{
    if (CheckboxCheckedChanged != null)
        CheckboxCheckedChanged(this, e);
}

private void checkbox2_CheckedChanged(object sender, EventArgs e)
{
    OnCheckboxCheckedChanged(e);
}

And then in Client:

ui1.CheckboxCheckedChanged += ui1_CheckboxCheckedChanged;
private void ui1_CheckboxCheckedChanged(object sender, CheckBoxEventArgs e)
{
    // Your code here
}

Answer 3

I'll be building on noMad17's answer, you have to subscribe to your CheckBox event in your UserInterface form. But the change is that now we will send the CheckBox that was clicked in the event. So this code is for your UserInterface form:

public event EventHandler SomeEvent;
protected void OnSomeEvent(object sender, EventArgs e)
{
    EventHandler eh = SomeEvent;
    if(eh != null)
    {
        eh(sender, e);
    }
}

private void checkBox2_CheckedChanged(object sender, EventArgs e)
{
    OnSomeEvent(sender, e);
}

Now for the Client, it needs to know what a UserInterface is so we have to pass UserInterface to the Client in the constructor, otherwise it won't initialize. Also here we are gonna work out the CheckBox event that the parent form is gonna give us. And in the end we have to unsubscribe the event. So this code is for your Client:

public partial class Client : Form
{
    private UserInterface ui1;

    public Client(UserInterface ui1)
    {
        InitializeComponent();
        this.ui1 = ui1;
        ui1.SomeEvent += UI1_SomeEvent;
    }

    private void UI1_SomeEvent(object sender, EventArgs e)
    {
        //Your code...
        CheckBox c = sender as CheckBox;
        if(c.Checked == true)
        {
            MessageBox.Show("true");
        }
        else
        {
            MessageBox.Show("false");
        }
    }

    private void Client_FormClosing(object sender, FormClosingEventArgs e)
    {
        ui1.SomeEvent -= UI1_SomeEvent;
    }
}