CODEWITHSUNDEEP
c#panelwindows-forms-designer
Annonymous177
Annonymous177

Reputation: 563

How to make my panel stop flickering

Hi i am trying to make a panel that will show some text when it hovered over a picture and i want it to follow the cursor so i 

System.Windows.Forms.Panel pan = new System.Windows.Forms.Panel();
    public Form1()
    {
        InitializeComponent();
        Product p = new Product();
        p.SetValues();
        this.pictureBox1.Image = (Image)Properties.Resources.ResourceManager.GetObject("pictureName");

    }

    private void pictureBox1_MouseEnter(object sender, EventArgs e)
    {
        pan.Height = 200;
        pan.Width = 100;
        pan.BackColor = Color.Blue;
        this.Controls.Add(pan);
        pan.BringToFront();
        //pan.Location = PointToClient(Cursor.Position);
    }

    private void pictureBox1_MouseLeave(object sender, EventArgs e)
    {
        Controls.Remove(pan);
    }

    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        pan.Location = PointToClient(Cursor.Position);  
    }

I tried adding this.doublebuffered = true; but it just make it look like there are after image of the panel when i move my mouse

when i hover over my picture it shows the panel but it flickers like crazy is this normal or is there a fix for this or this is my computers problem

Upvotes: 0

Views: 4927

Answers (1)

TaW
TaW

Reputation: 54453

Adding this.DoubleDuffered = true; to the Form does only affect the Form, not the Panel.

So use a doubleBuffered Panel subclass:

class DrawPanel : Panel
{
    public DrawPanel ()
    {
      this.DoubleBuffered = true;
    }
}

However moving large things around will take its toll. Btw, the PictureBox class is already doubleBuffered. Also it seems more logical to add the Panel to the PictureBox, not the Form: pictureBox1.Controls.Add(pan); And adding a pictureBox1.Refresh(); to the MouseMove.

Update: As you don't draw on the Panel and also need to it to overlap the PictureBox the above ideas do not really apply; using the subclass is not necessary, although it may come handy at some point. And yes, the Panel needs to be added to the Form's Controls collection!

This code works just fine here:

public Form1()
{
    InitializeComponent();

    // your other init code here

    Controls.Add(pan);  // add only once
    pan.BringToFront();
    pan.Hide();         // and hide or show
    this.DoubleDuffered = true  // !!
}

private void pictureBox1_MouseLeave(object sender, EventArgs e)
{
    pan.Hide();         // hide or show
}

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
    pan.Location = pictureBox1.PointToClient(Cursor.Position);
    pictureBox1.Refresh();  // !!
    Refresh();              // !!
}

private void pictureBox1_MouseEnter(object sender, EventArgs e)
{
    pan.Height = 200;
    pan.Width = 100;
    pan.BackColor = Color.Blue;
    pan.Location = pictureBox1.PointToClient(Cursor.Position);
    pan.Show();        // and hide or show
}

Looks like you were missing the right combination of doublebuffering the Form and refreshing both, the Form and the PictureBox.

Upvotes: 3

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