Move image (Picturebox) in form

Question

How to move an image in a windows form.

I used the following code:

private void button1_Click(object sender, EventArgs e)
{
    int tamanhoFundo = picFundo.Width;
    int x = myPic.Location.X;
    int y = myPic.Location.Y;
    while (x < tamanhoFundo)
    {
        int pos = x += 5;
        myPic.Location = new Point(pos, myPic.Location.Y);
        Thread.Sleep(500);
    }
}

It even moves the image, only there’s a trace:

How to prevent this?

Answer 1

If the image is above the picFundo, before calling the Thred.Sleep give a Refresh() in the background. Look at the code below:

private void button1_Click(object sender, EventArgs e)
{
    int tamanhoFundo = picFundo.Width;
    int x = myPic.Location.X;
    int y = myPic.Location.Y;
    while (x < tamanhoFundo)
    {
        int pos = x += 5;
        myPic.Location = new Point(pos, myPic.Location.Y);
        picFundo.Refresh();
        Thread.Sleep(500);
    }
}

Answer 2

This occurs in a purposeful form of self System.Windows.Forms, because of increasing the performance of window rendering. But you can disable this with the method Refresh() and Update(), the two are great to render your window. see the example based on your code:

private void button1_Click(object sender, EventArgs e)
{
  int tamanhoFundo = picFundo.Width;
  int x = myPic.Location.X;
  int y = myPic.Location.Y;
  while (x < tamanhoFundo)
  {
     int pos = x += 5;
     myPic.Location = new Point(pos, myPic.Location.Y);
     myPic.Refresh(); myPic.Update();
     Thread.Sleep(250); // Também é bom reduzir o tempo de Sleep, pois os métodos Refresh() e Update() consomem um pouco de memória para re-criar o componente, então, de 500 vamos colocar 250.
  }
}