CODEWITHSUNDEEP
c#winforms
cce1911
cce1911

Reputation: 353

User control event handler subscription

I have a windows forms app with a user control. I'm trying to get the UC to call a function on the main form, but when I add the UC, the main form can't see the public event.

My UC looks like this:

public partial class uctlLogin: UserControl
{
    public delegate void ButtonClickedEventHandler(object sender, EventArgs e);
    public event ButtonClickedEventHandler OnUserControlButtonClicked;

    public uctlLogin()
    {
        InitializeComponent();
        btnLogin.Click += new EventHandler(OnButtonClicked);
    }

    private void OnButtonClicked(object sender, EventArgs e)
    {
        if (OnUserControlButtonClicked != null)
            OnUserControlButtonClicked(this, e);
    }
}

My form code is:

public partial class frmMain : Form
{
    UserControl uctlLogin1 = new TabletUserControls.uctlLogin();

    public frmMain()
    {
        InitializeComponent();
        uctlLogin1.OnUserControlButtonClicked += new EventHandler(OnUCButtonClicked);
    }

    private void OnUCButtonClicked(object sender, EventArgs e)
    {
        MessageBox.Show("Horray!");
    }

    private void frmMain_Load(object sender, EventArgs e)
    {
        this.Controls.Add(uctlLogin1);

    }
}

The problem is in this line:

uctlLogin1.OnUserControlButtonClicked += new EventHandler(OnUCButtonClicked);

Generates the following message:

'System.Windows.Forms.UserControl' does not contain a definition for 'OnUserControlButtonClicked' and no extension method 'OnUserControlButtonClicked' accepting a first argument of type 'System.Windows.Forms.UserControl' could be found (are you missing a using directive or an assembly reference?)

I've tried putting the UC in the same project and creating the UC in a separate project, then adding a reference to it. After Googling for hours, I'm stuck. Any idea what I'm missing here?

BTW, I'm using VS2012 targeting the .Net Framework 4.5.

Upvotes: 0

Views: 662

Answers (1)

Thomas Levesque
Thomas Levesque

Reputation: 292345

That's because in your frmMain, you declared uctlLogin1 as UserControl, rather than uctlLogin. The type UserControl doesn't have a OnUserControlButtonClicked event, and the compiler doesn't know that uctlLogin1 is an instance of uctlLogin, since you declared it as UserControl. Just specify the actual type of uctlLogin1 and it will work fine.

Upvotes: 3

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