图片问题

[dlqycyz]

我在picturebox上打开了一幅图片，并且备份了一附件，我对附件进行操作，当我想关闭该图片（并不关闭窗口）的同时怎样删掉附件？部分程序如下：

accessoryFileName = currentFileName.Insert(aa-4,"~1");
File.Copy(currentFileName,accessoryFileName,true);

Bitmap b = new Bitmap(accessoryFileName);

//bitmap = (Bitmap)b.Clone();
bitmap = b;

／／删掉附件
private void MenuItemFile_Close(object sender, System.EventArgs e)
{
Redo = 0;
this.redo.Enabled = false;
this.undo.Enabled = false;
//this.bitmap.Dispose();
//this.bitmap = null;
//this.pictureBox1.Dispose();
this.Dispose();

File.Delete(accessoryFileName);／／这里好像部队该怎么办？？？

this.Refresh();
}