DevExpress的GridControl的實時加載數據解決方案（取代分頁）

http://blog.csdn.net/educast/article/details/4769457

evExpress是一套第三方控件

其中有類似DataGridView的控件

今天把針對DevExpress.XtraGrid.GridControl實時加載數據的功能開發出來了

分享給大家

歡迎討論

Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using DevExpress.XtraGrid;
using DevExpress.XtraGrid.Views.Grid;
namespace Life365.CallCenter
{
public class GridCreator<T> where T: new()
    {
//一頁有多少條數據
private int page_size = 30;
public int PageSize
        {
get { return page_size; }
        }
/// <summary>
/// 過濾條件
/// </summary>
public string Filter
        {
get;
set;
        }
/// <summary>
/// 排序條件
/// </summary>
public string OrderBy
        {
get;
set;
        }
/// <summary>
/// 數據訪問類
/// </summary>
public BaseProxy Proxy
        {
get;
set;
        }
private int row_count;
/// <summary>
/// 總行數
/// </summary>
public int RowCount
        {
get {return row_count;}
        }
private int page_num = 1;
/// <summary>
/// 當前的數據頁
/// </summary>
public int PageNum
        {
get { return page_num; }
        }
//緩存的數據
private List<T> data_list = new List<T>();
private GridCreator()
        { 
        }
/// <summary>
/// 構造函數
/// </summary>
public GridCreator(GridControl grid,BaseProxy proxy)
        {
            ((GridView)grid.MainView).TopRowChanged += new EventHandler(grid_TopRowChanged);
this.Proxy = proxy;
            grid.DataSource = data_list;
        }
/// <summary>
/// 獲取前兩頁數據
/// </summary>
private void GetTwoPageData()
        {
            data_list.InsertRange(0, GetData());
            page_num++;
            data_list.InsertRange(page_size, GetData());
        }        
/// <summary>
/// grid下拉事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void grid_TopRowChanged(object sender, EventArgs e)
        {
            GridView grid = sender as GridView;
if (grid.TopRowIndex >= (page_num - 1) * page_size)
            {
//當看完一頁數據的時候開始取數據
                page_num++;
                List<T> test = GetData();
                data_list.InsertRange((page_num - 1)* page_size, test);
            }
        }
/// <summary>
/// 實時的加載數據函數
/// </summary>
/// <returns></returns>
public List<T> GetData()
        {
return Proxy.GetDataList(this.Filter, this.OrderBy, this.page_size,this.page_num, ref this.row_count) as List<T>;
        }
    }
}

T泛型約束是需要加載數據的類型

BaseProxy是訪問數據庫的基類，其中包含GetDataList的虛方法

繼承自BaseProxy的GetDataList為

Code
public override object GetDataList(string filter, string order_by, int page_size, int page_num, ref int count)
        {
            count = 1000;
            List<RegionEntity> regions = new List<RegionEntity>();
for (int i = 0; i < page_size; i++)
            {
                regions.Add(new RegionEntity() { SR_RegionName = ((page_num-1)*page_size+i).ToString() });
            }
return regions;
        }

這里的RegionEntity就是前面提到的某一種類型的T

數據提供程序是模擬出來的（測試驅動開發，哈哈）

你可以在這個函數里寫數據庫訪問方法

具體調用方法如下

Code
GridCreator<RegionEntity> creator = new GridCreator<RegionEntity>(gridShop,new UtilsProxy());

UtilsProxy類繼承自BaseProxy並重寫了GetDataList方法

gridShop就是當前窗體的DevExpress.XtraGrid.GridControl控件

RegionEntity針對泛型類型

用起來還是蠻方便的