检测对MDI子项的更改

Question

Is there a way to detect changes to MDI child when one of the child is closed?

I'm trying to create a dynamic dropdown menu item in the toolstrip menu item that can be add or remove programatically from the MDI child.

Because of the instance is dispose when the child is close,i couldn't cross check with the toolstrip menu item.The adding part is successful but the removing part is a problem.

            ToolStripMenuItem temp = new ToolStripMenuItem();
            if(form.Visible == true)
            {
                this.SuspendLayout();
                temp.Name = form.Text;
                temp.Size = new System.Drawing.Size(112, 22);
                temp.Text = form.Text;

                this.windowsToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { temp });
                this.ResumeLayout();
            }

Answer 1

You should use FormClosing event. It executes before disposing the instance of the form. FormClosed event fires after disposing of the form's instance.