Apply parent mouse events to child elements

Question

I am making little Windows Forms Application.
I have PictureBox (parent) and Label (child) in it.

The Parent's Mouse Events are working perfectly, but Mouse events generated by child elements are not reflected on the Parent. The Cursor also changes back to its default (arrow).

Is it possible to pass events generated by child Controls, e.g., the MouseEnter event, to the Parent Control?

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        Card.MouseEnter += new EventHandler(Card_MouseEnter);
        Card.MouseLeave += new EventHandler(Card_MouseLeave);
        Card.MouseDown += new MouseEventHandler(this.Card_MouseDown);
        Card.MouseUp += new MouseEventHandler(this.Card_MouseUp);
    }

    void Card_MouseLeave(object sender, EventArgs e)
    {
        this.Card.BackgroundImage = ((System.Drawing.Image)(Properties.Resources.card_bg));
        this.Rename("Running!");
    }

    void Card_MouseEnter(object sender, EventArgs e)
    {
        this.Card.BackgroundImage = ((System.Drawing.Image)(Properties.Resources.card_hover_bg));
    }

    private void Card_MouseDown(object sender, EventArgs e)
    {
        this.Card.BackgroundImage = ((System.Drawing.Image)(Properties.Resources.card_click_bg));
    }

    private void Card_MouseUp(object sender, EventArgs e)
    {
        this.Card.BackgroundImage = ((System.Drawing.Image)(Properties.Resources.card_hover_bg));
        this.Rename("Please Wait...");
    }

    private void CardName_MouseDown(object sender, MouseEventArgs e)
    {
        
    }

    void Rename(string args)
    {
        this.CardName.Text = args;
    }

    private void CardName_Click(object sender, EventArgs e)
    {

    }
}

         

            This is what I have                       This is what I want to achieve
    

The first animation represents what I have now, the second is what I need to achieve :)

Answer 1

First of all, you should build a UserControl as a container for all your objects: it'd make everything simpler (the one I'm using here is actually a UserControl, modified to comply with your current setup).

When a Control other than the PictureBox is interacted with, you can decide whether you want to trigger a similar action on the main Control or perform a different action based on what event has been generated.

▶ When the Mouse Pointer enters you assembled Control, you want to change the default Cursor: then, when one of the Labels raises the Enter event, call the method of the main Control that handles this. An event handler is a method, you can call it.

▶ When a Label is clicked, you don't want to trigger the related action of the main Control: in this case, there's nothing to do, just handle this event and perform the required action.

▶ The Label should be child of the main Control. You're using a PictureBox, which is not a ContainerControl. You can add child controls to it anyway. You need to do this in code, since - as mentioned - the PictureBox is not designed to host Controls, thus you cannot drop one inside it: the Control you drop will be parented with the Container that hosts the PictureBox (your Form, here).
When you set the parent in code, you need to remember that the Location of the child control is relative to the old Parent, so you have to re-define it's position.

E.g: PictureBox.Bounds = (100, 100, 100, 200) / Label.Bounds = (100, 250, 100, 50)

When the PictureBox becomes Parent of your Label, the Label.Location is still (100, 250): so, now, it will be hidden, since it's outside the visible bounds of its new Parent. You have to reposition it in relation to the new host: its new Location should be (0, 150), to keep the previous relative position.

PictureBox.Control.Add(Label);
//[...]
Label.Location = new Point(Label.Left - PictureBox.Left, Label.Top - PictureBox.Top);
=> Label.Location = (100 - 100, 250 - 100) => (0, 150)

Or, centered horizontally:

Label.Location = new Point((PictureBox.Width - Label.Width) / 2, Label.Top - PictureBox.Top);
=> Label.Location = ((100 - 100) / 2, 250 - 100) => (0, 150) // <- Since both have the same Width

Or, using positions relative to the Screen:

var p = Label.PointToScreen(Point.Empty);  // Relative to the ClientRectangle (Top/Left = (0, 0))
PictureBox.Controls.Add(Label);
Label.Location = PictureBox.PointToClient(p);

In any case, call BringToFront() after, to ensure that the new child Control is brought on top and anchor the Control, so it will keep its position and its Width will be bound to the Parent Width:

Label.BringToFront();
Label.Anchor = AnchorStyles.Left | AnchorStyles.Bottom | AnchorStyles.Right;

Now, assuming you want to change the Cursor to Cursors.Hand when the Mouse enters your combined Control and reset to default when it leaves it:

▶ You want the Cursor to change shape in any case.
▶ You want to generate different actions when the PictureBox is clicked and when one of the Labels is clicked.
▶ Both Labels can have distinct actions when clicked.

→ _{In the visual sample, the Label above the PictureBox is named lblTitle, the Label inside the PictureBox, at the bottom, is named lblFooter}.
→ _{The PictureBox is named ImageView}.

Setup the handlers:

NOTE: With a UserControl, the events handling, e.g., in relation to MouseEnter, changes in:

// The Parent's MouseEnter calls OnMouseEnter
protected override void OnMouseEnter(EventArgs e)
{
    base.OnMouseEnter(e);
    this.Cursor = Cursors.Hand;
}

// Child Controls just call the same method
private void Labels_MouseEnter(object sender, EventArgs e) => OnMouseEnter(e);

---

public Form1()
{
    InitializeComponent();

        Point p = lblFooter.PointToScreen(Point.Empty); 
        ImageView.Controls.Add(lblFooter);
        lblFooter.Location = ImageView.PointToClient(p);

        ImageView_MouseEnter += ImageView_MouseEnter;
        ImageView_MouseLeave += ImageView_MouseLeave;
        // Not added in the code here, do whatever is needed with this handler
        ImageView_Click += ImageView_Click;

        lblFooter.MouseEnter += Labels_MouseEnter;
        lblFooter.MouseLeave += Labels_MouseLeave;
        lblFooter.MouseClick += lblFooter_MouseClick;

        lblTitle.MouseEnter += Labels_MouseEnter;
        lblTitle.MouseLeave += Labels_MouseLeave;
        lblTitle.MouseDown += lblTitle_MouseDown;
        lblTitle.MouseUp += lblTitle_MouseUp;
}

private void ImageView_MouseEnter(object sender, EventArgs e) => this.Cursor = Cursors.Hand;

private void ImageView_MouseLeave(object sender, EventArgs e) => this.Cursor = Cursors.Default;

private void Labels_MouseEnter(object sender, EventArgs e)
{
    ImageView_MouseEnter(ImageView, e);
    // [...]
    // Do stuff related to the Labels Enter event
}

private void Labels_MouseLeave(object sender, EventArgs e) {
    ImageView_MouseLeave(ImageView, e);
}

private void lblTitle_MouseDown(object sender, MouseEventArgs e) {
    // Perform actions when the Mouse button is held down lblTitle
}

private void lblTitle_MouseUp(object sender, MouseEventArgs e) {
    // Perform actions when the Mouse button is released
}

private void lblFooter_MouseClick(object sender, MouseEventArgs e) {
    // Perform actions on a Mouse Click event on lblFooter
}

Answer 2

When I'm making pictureBox1.Controls.Add(label1) label1 is disappearing and I tried bring to front and change color but couldn't do it. Please if you will have any idea show me in provided code by me to be understandable for me. Thank you all again and again :)

You'd use code like this, maybe in the Load() event of the Form:

private void Form1_Load(object sender, EventArgs e)
{
    Point pt = CardName.Parent.PointToScreen(CardName.Location);
    Card.Controls.Add(CardName);
    CardName.Location = Card.PointToClient(pt);
}

This keeps the label in the same position as it was, but makes the picturebox the parent.

Not sure where you're going wrong. Here's an example showing it in action. Both the PictureBox (Card) and Label (CardName) are inside a Panel (panel1). Clicking on button2 toggles the visibility of the Card. Clicking on button1 makes Card the Parent of CardName. You can see that at first, only the Card toggles visibility, but after clicking on button1 and setting the Parent, both toggle visibility together since CardName is a Child of Card (it also changes its BackColor to match that of its new Parent):

Code:

public partial class Form1 : Form
{

    private void button1_Click(object sender, EventArgs e)
    {
        Point pt = CardName.Parent.PointToScreen(CardName.Location);
        Card.Controls.Add(CardName);
        CardName.Location = Card.PointToClient(pt);
    }

    private void button2_Click(object sender, EventArgs e)
    {
        Card.Visible = !Card.Visible;
    }

}

When I move mouse over label, panel thinks mouse left it and rises MouseLeave event

Here is how you can tell if the cursor has actually left the BOUNDS of the Panel, as opposed to simply enter a child control within the Panel:

private void panel1_MouseEnter(object sender, EventArgs e)
{
    panel1.BackColor = Color.Red;
}

private void panel1_MouseLeave(object sender, EventArgs e)
{
    Point pt = panel1.PointToClient(Cursor.Position);
    if (!panel1.ClientRectangle.Contains(pt))
    {
        // we only get in here when the cursor leaves the BOUNDS of panel1
        panel1.BackColor = Control.DefaultBackColor;
    }            
}