private void btnEdit_Click(object sender, EventArgs e)
        {
            ListViewItem item = this.listView1.SelectedItems[0];
            frmLayerInfo info = new frmLayerInfo
            {
                LayerName = item.Text,
                MinScale  = double.Parse(item.SubItems[1].Text),
                MaxScale  = double.Parse(item.SubItems[2].Text)
            };

            if (info.ShowDialog() == DialogResult.OK)
            {
                string[] strArray = new string[3];
                strArray[0] = info.LayerName;
                if ((strArray[0] != item.Text) && this.LayerNameIsExist(strArray[0]))
                {
                    MessageBox.Show("图层已存在");
                }
                else
                {
                    strArray[1]           = info.MinScale.ToString();
                    strArray[2]           = info.MaxScale.ToString();
                    item.Text             = strArray[0];
                    item.SubItems[1].Text = strArray[1];
                    item.SubItems[2].Text = strArray[2];
                    XmlNode tag = item.Tag as XmlNode;
                    for (int i = 0; i < tag.Attributes.Count; i++)
                    {
                        XmlAttribute attribute = tag.Attributes[i];
                        if (attribute.Name.ToLower() == "name")
                        {
                            attribute.Value = strArray[0];
                        }
                        else if (attribute.Name.ToLower() == "minscale")
                        {
                            attribute.Value = strArray[1];
                        }
                        else if (attribute.Name.ToLower() == "maxscale")
                        {
                            attribute.Value = strArray[2];
                        }
                    }
                }
            }
        }
        private void btnAdd_Click(object sender, EventArgs e)
        {
            frmLayerInfo info = new frmLayerInfo();

            if (info.ShowDialog() == DialogResult.OK)
            {
                string[] items = new string[] { info.LayerName, info.MinScale.ToString(), info.MaxScale.ToString() };
                if (this.LayerNameIsExist(items[0]))
                {
                    MessageBox.Show("图层已存在");
                }
                else
                {
                    ListViewItem item = new ListViewItem(items);
                    this.listView1.Items.Add(item);
                    XmlNode newChild = this.CreateLayerNode(items[0], items[1], items[2]);
                    item.Tag = newChild;
                    this.m_pLayerSettingsNode.ChildNodes[0].AppendChild(newChild);
                }
            }
        }