C# – User control in windows forms application

cwinforms

I have a simple user control with a text box and label in it. I created public properties to access the text in the textbox when I use the user control in another form.

My problem is the property is returning null value when I call it in the form. Am i missing anything?

My property is as follows::

 public partial class UserControl1 : UserControl
 {
        public UserControl1()
        {
            InitializeComponent();
        }

        public string rtnTxtMake
        {  
            get 
            { 
                return txtMake.Text; 
            }
            set 
            { 
                txtMake.Text = value; 
            } 
        }
 }

and in the next forms button click event i call the property as follows

        UserControl1 Usc = new UserControl1();
        string Make = Usc.rtnTxtMake;

        MessageBox.Show(Make)

Best Answer

UserControl1 Usc = new UserControl1();
string Make = Usc.rtnTxtMake;

If your user control has by default an empty textbox field, then it seems correct that the above two lines of code would return either null or String.Empty (check via String.IsNullOrEmpty), since you explicitly create a new instance of your user control.

I suppose what you really want is this:

  • You have inserted a user control into a form in the Designer. Let's call this user control instance ctlUser.

  • You have a button with a Click event handler. The last few lines of code in your question are from that handler method.

  • In the handler, you wouldn't create a new instance of your user control (Usc) but refer to the one that you previously inserted into your form, ctlUser. Then things should work as expected.

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