删除C＃中flowlayoutpanel中的所有控件

Question

I'm building a flow layout panel whose each control represents for a room. I want to reload all room by removing all controls in the panel and adding new controls.

I used:

foreach(Control control in flowLayoutPanel.Controls) 
{
    flowLayoutPanel.Controls.Remove(control);
    control.Dispose(); 
}

but some of controls couldn't be removed.

I tried to find a solution on the internet but found nowhere.

Could any body help?

Answer 1

That's because you are removing the controls from the same list you are iterating. Try something like this

List<Control> listControls = flowLayoutPanel.Controls.ToList();

foreach (Control control in listControls)
{
    flowLayoutPanel.Controls.Remove(control);
    control.Dispose();
}

Maybe not like that, but you get the idea. Get them in a list, then remove them.

Answer 2

According to MSDN, you can clear all controls from a ControlCollection (such as a FlowLayoutPanel ) by calling the Clear() method . For example:

flowLayoutPanel1.Controls.Clear();

Be aware: just because the items are removed from the collections does not mean the handlers are gone and must be disposed of properly less you face memory leaks.

Answer 3

Note: this is a working solution based on the previous comment, so credits to that person :)

This worked for me:

List<Control> listControls = new List<Control>();

foreach (Control control in flowLayoutPanel1.Controls)
{
     listControls.Add(control);
}

foreach (Control control in listControls)
{
     flowLayoutPanel1.Controls.Remove(control);
     control.Dispose();
}

There is probably a better/cleaner way of doing it, but it works.

Answer 4

If you are looking for an easy and quick solution. Here it is.

while (flowLayoutPanel.Controls.Count > 0) flowLayoutPanel.Controls.RemoveAt(0);