How to access controls on hosted form in a user control WinForm

Question

In visual studio how do you access a control on a form hosting a user control? For example, when text changes in a text-box in a user control, I want text in another text-box in another user control to change. Both these user controls are hosted on the same form. Thanks in advance!

Palfrey

Raise an event from your userControl, have the form or other UC subscribe to the event. Begs the question if they are that closely related, why are they on different controls? – Napier

Can you be more specific? Why you need such integration between 2 controls at design time? – Mcgrew

Plutonix, they are on separate controls because the user is able to decide which user control that want to display on the form. It could be either one or both. If both are displaying at the same time, the text needs to match. – Palfrey

Reza, it is a SOAP client application that gives the user two different ways to enter data to make a request. – Palfrey

If I need different UI for data entry, I prefer to have 2 controls with different UI, but I will use a single data source for them and handle the scenario using data-binding. If you bind both controls to a single data source, while you can have different UI, you have a single data and both controls data are sync. I shared a solution for your question :) – Mcgrew

Answer 1

If you need different UI for data entry, I prefer to have 2 controls with different UI, but I will use a single data source for them and handle the scenario using data-binding.

If you bind both controls to a single data source, while you can have different UI, you have a single data and both controls data are sync.

The answer to your question:

You can define a property in each control which set Text of TextBox. Then you can handle TextChanged event of the TextBox and then find the other control and set the text property:

Control1

public partial class MyControl1 : UserControl
{
    public MyControl1() { InitializeComponent(); }

    public string TextBox1Text
    {
        get { return this.textBox1.Text; }
        set { this.textBox1.Text = value; }
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        if (Parent != null)
        {
            var control1 = Parent.Controls.OfType<MyControl2>().FirstOrDefault();
            if (control1 != null && control1.TextBox1Text != this.textBox1.Text)
                control1.TextBox1Text = this.textBox1.Text;
        }
    }
}

Control2

public partial class MyControl2 : UserControl
{
    public MyControl2() { InitializeComponent(); }

    public string TextBox1Text
    {
        get { return this.textBox1.Text; }
        set { this.textBox1.Text = value; }
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        if (Parent != null)
        {
            var control1 = Parent.Controls.OfType<MyControl1>().FirstOrDefault();
            if (control1 != null)
                control1.TextBox1Text = this.textBox1.Text;
        }
    }
}

Mcgrew

Thanks so much! Works perfectly. – Palfrey