如何将控件添加到集合的开头？

Question

For example;

panel1.Controls.Add(myControl); add to end of the collection.

Is there a way to add to the beginning of the collection without replacing the one at the beginning?

panel1.Controls.AddAt(0, myControl) replaces the control at 0.

update

actually it seems to work and not replace it. i might have gotten it wrong.

Answer 1

You can use ControlCollection.SetChildIndex method.

Sets the index of the specified child control in the collection to the specified index value.

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When SetChildIndex is called, the Control referred to by the child parameter is moved to the position specified by newIndex and the other Control references in the Control.ControlCollection are reordered to accommodate the move.

Answer 2

try this :

List<Literal> persistControls = new List<Literal>();
protected void Page_Load(object sender, EventArgs e)
{          
     display();           
}

protected void commentButton_Click(object sender, EventArgs e)
{
    Literal myComment = new Literal();
    myComment.Text = "<p>" + commentBox.Text + "</p><br />";
    commentPanel.Controls.Add(myComment);
    persistControls.Insert(0,myComment);
    Session["persistControls"] = persistControls; 
    display();
}
void display()
{
    // if you already have some literal populated
    if (Session["persistControls"] != null)
    {
        // pull them out of the session
        persistControls = (List<Literal>)Session["persistControls"];
        foreach (Literal ltrls in persistControls)
            commentPanel.Controls.Add(ltrls); // and push them back into the page
    }
}