Deverpress笔记之TreeList、Grid.

声明：此笔记仅为方便本人记忆，写的的一些小技巧，因项目工期较紧，代码未来得及整理，也并未全部在项目中采用，不一定适用于您的开发，故仅供参考之用！ 如您在此控件使用过程中遇到类似问题需要解决。欢迎一起讨论。

一、TreeList的GetStateImage事件应用。
方法一：此事件用于在tree之前设置显示的图片，具体使用方法是首先在窗体上放置imagelist,设置好图片，即可在事件中判断后，选择要显示的图片的索引值即可。

  private void treeList_GetStateImage(object sender, DevExpress.XtraTreeList.GetStateImageEventArgs e) 
  {
   CheckState check = GetCheckState(e.Node.Tag);
   if(check == CheckState.Unchecked)
    e.NodeImageIndex = 0;
   else if(check == CheckState.Checked)
    e.NodeImageIndex = 1;
   else e.NodeImageIndex = 2;
  }

方法二：为tree中指定的节点区分现实不同的图片。
事例代码如下：

        private void roleTree_GetStateImage(object sender, DevExpress.XtraTreeList.GetStateImageEventArgs e)
        {
            if(e.Node.Id.ToString() == "0")
            {
                this.roleTree.Nodes[0].RootNode.StateImageIndex = 1;
            }
            else
            {
                e.NodeImageIndex = 0;
            }
        }

二、TreeList中运用MouseDown事件获取所选节点信息。
提取tree中的值所用事件为MouseDown，在事件中填写如下代码

private void roleTree_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if(e.Button == MouseButtons.Left) 
            {
                DevExpress.XtraTreeList.TreeListHitInfo hInfo = roleTree.GetHitInfo(new Point(e.X, e.Y));
                if(hInfo.HitInfoType == DevExpress.XtraTreeList.HitInfoType.StateImage)
                {
//                  this.roleTree.DeleteNode(hInfo.Node);
                    if(MessageBox.Show("你确定要删除"+hInfo.Node[1].ToString()+"角色","提示信息",MessageBoxButtons.YesNo,MessageBoxIcon.Question)==DialogResult.Yes)
                    {
                        TB_Accounts_RolesEntity role = new TB_Accounts_RolesEntity();
                        role.iRoleID = Convert.ToInt32(hInfo.Node[1].ToString());
                        role.Retrieve();
                        role.Delete();
                        InitRoleTree();
                    }
                    else
                    {}
                }
                else if(hInfo.HitInfoType == DevExpress.XtraTreeList.HitInfoType.Cell)
                {
//                    MessageBox.Show(hInfo.Node[1].ToString());    //获取选择的iRoleID
//                    SetCheckedNode(treeList.Nodes[0].Nodes[0]); 

                    //得到指定iRoleID的全部的vDescript的允许的Table
                    string roleID = hInfo.Node[1].ToString();
                    string sqlString="SELECT dbo.TB_Accounts_Permissions.vDescript FROM dbo.TB_Accounts_Permissions INNER JOIN  dbo.TB_Accounts_RolePermissions ON dbo.TB_Accounts_Permissions.iPermissionID = dbo.TB_Accounts_RolePermissions.iPermissionID WHERE 1=1"; //编写SQL语句
                    sqlString +=" and dbo.TB_Accounts_RolePermissions.iRoleID = '"+roleID+"'"; 
                    //执行SQL语句
                    DataTable dt=Query.ProcessSql(sqlString,"EasySales"); 

                    for(int i = 0; i<dt.Rows.Count; i++)
                    {
                        string treeText = treeList.GetNodeByVisibleIndex(i).GetDisplayText(0).ToString();
                        if(treeText == dt.Rows[i]["vDescript"].ToString())
                        {
                            SetCheckedNode(treeList.Nodes[0].Nodes[i]); 
                        }                                
                    }



/**///////                    //判断treeList的行数和DataTable的行数是否一致
//////                    if(this.treeList.VisibleNodesCount.ToString()==dt.Rows.Count.ToString())
//////                    {
//////
//////                        //循环treeList的全部的vDescript的值
//////                        for(int i = 0; i<Convert.ToInt32(this.treeList.VisibleNodesCount.ToString());i++)
//////                        {
//////                            //判断treeList的vDescript的值和Table的vDescipte的值是否相等
//////                            if(this.treeList.GetNodeByVisibleIndex(i).GetDisplayText(0).ToString() != dt.Rows[i]["vDescript"].ToString())
//////                            {
//////                                MessageBox.Show("得到不同的vDescript");
////////                                Checked();
//////                            }
//////                            else
//////                            {
//////                                MessageBox.Show("得到相同的vDescript");
////////                                UnChecked();
//////                            }
//////                        }
//////                    }
//////                    else
//////                    {
//////                        MessageBox.Show("长度不一致");
//////                    }
                }
            }
        }

三、TreeList前添加CheckBox的选择框，可实现点击父节点相应子节点全部选中的效果。
TreeList中并为提供对应实现此功能的CheckBox自定义列，故必须用上面提到的GetStateImage事件添加三个（全选、部分全选、为选中）CheckBox的图片，具体样式可自己设计，然后放到窗体中的ImageList中去，触发及调用用到下面的代码：

        private CheckState GetCheckState(object obj) 
        {
            if(obj != null) return (CheckState)obj;
            return CheckState.Unchecked;
        }

        private void SetCheckedNode(string treeText)
        {
            CheckState check = new CheckState();
            check = CheckState.Checked;
        }
        private void SetCheckedNode(DevExpress.XtraTreeList.Nodes.TreeListNode node) 
        {
            CheckState check = GetCheckState(node.Tag);
            if(check == CheckState.Indeterminate || check == CheckState.Unchecked) check = CheckState.Checked;
            else check = CheckState.Unchecked;
            treeList.BeginUpdate();
            node.Tag = check;
            SetCheckedChildNodes(node, check);
            SetCheckedParentNodes(node, check);
            treeList.EndUpdate();
        }
        private void SetCheckedChildNodes(DevExpress.XtraTreeList.Nodes.TreeListNode node, CheckState check) 
        {
            for(int i = 0; i < node.Nodes.Count; i++) 
            {
                node.Nodes[i].Tag = check;
                SetCheckedChildNodes(node.Nodes[i], check);
            }
        }
        private void SetCheckedParentNodes(DevExpress.XtraTreeList.Nodes.TreeListNode node, CheckState check) 
        {
            if(node.ParentNode != null) 
            {
                bool b = false;
                for(int i = 0; i < node.ParentNode.Nodes.Count; i++) 
                {
                    if(!check.Equals(node.ParentNode.Nodes[i].Tag)) 
                    {
                        b = !b;
                        break;
                    }
                }
                node.ParentNode.Tag = b ? CheckState.Indeterminate : check; 
                SetCheckedParentNodes(node.ParentNode, check);
            }
        }
        private void treeList_GetStateImage(object sender, DevExpress.XtraTreeList.GetStateImageEventArgs e) 
        {
            CheckState check = GetCheckState(e.Node.Tag);
            if(check == CheckState.Unchecked)
                e.NodeImageIndex = 0;
            else if(check == CheckState.Checked)
                e.NodeImageIndex = 1;
            else e.NodeImageIndex = 2;
        }

        private void treeList_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e) 
        {
            if(e.KeyData == Keys.Space) 
                SetCheckedNode(treeList.FocusedNode);
        }

        private void treeList_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) 
        {
            if(e.Button == MouseButtons.Left) 
            {
                DevExpress.XtraTreeList.TreeListHitInfo hInfo = treeList.GetHitInfo(new Point(e.X, e.Y));
                if(hInfo.HitInfoType == DevExpress.XtraTreeList.HitInfoType.StateImage) 
                    SetCheckedNode(hInfo.Node);
            }
        }

        private void roleTree_GetStateImage(object sender, DevExpress.XtraTreeList.GetStateImageEventArgs e)
        {
            if(e.Node.Id.ToString() == "0")
            {
                this.roleTree.Nodes[0].RootNode.StateImageIndex = 1;
            }
            else
            {
                e.NodeImageIndex = 0;
            }
        }

这样就可实现上述功能。

四、Grid中设置、获取指定Cell的值，用下面的方法：
获取：GridView.GetRowCellValue()
设置：GridView.SetRowCellValue()

更进一步的使用技巧可在软件附带的Demo中学到。