增强 GridView 控件的功能

还记得雅虎的XX（不好意思，忘记姓甚名谁了）有一篇演讲，其中一个字就是“懒”。咱写代码的，不懒点儿还真是吃不消，尤其是现在这样要命的天气~~。

相信大家都多少有抱怨GridView控件的功能吧，咱在这就不多说了，贴出代码是最重要的。



该类增强了微软的GridView的功能，增加了“首页”、“上页”、“下页”、“尾页”按钮，方便大家使用，翻页事件也已经添加好，在相关页面只要添加以下代码就可以了：

    protected void Page_Init(object sender, EventArgs e) {
        Lyout.Web.Extension.GridView.RegisterEvents(listTable, new Lyout.Web.Extension.GridViewDataBind(BindData));
    }

记住必须在 Page_Init 里面。其中 listTable 为GridView控件的ID，BindData是自己绑定数据的方法的名称。

using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Lyout.Web.Extension {
    /**//// <summary>
    /// GridView 数据绑定委托
    /// </summary>
    public delegate void GridViewDataBind();

    /**//// <summary>
    /// 增强 GridView 的功能
    /// </summary>
    public sealed class GridView {
        /**//// <summary>
        /// 给指定的GridView控件添加RowCommand、RowCreated、PageIndexChanged事件
        /// </summary>
        /// <param name="gridView">需要注册事件的GridView控件</param>
        public static void RegisterEvents(System.Web.UI.WebControls.GridView gridView) {
            RegisterEvents(gridView, null, true);
        }

        /**//// <summary>
        /// 给指定的GridView控件添加RowCommand、RowCreated、PageIndexChanged事件
        /// </summary>
        /// <param name="gridView">需要注册事件的GridView控件</param>
        /// <param name="dataBind">数据绑定方法</param>
        public static void RegisterEvents(System.Web.UI.WebControls.GridView gridView, GridViewDataBind dataBind) {
            RegisterEvents(gridView, dataBind, true);
        }

        /**//// <summary>
        /// 给指定的GridView控件添加RowCommand、RowCreated、PageIndexChanged事件
        /// </summary>
        /// <param name="gridView">需要注册事件的GridView控件</param>
        /// <param name="dataBind">数据绑定方法</param>
        /// <param name="pageText">翻页按钮上的文字</param>
        public static void RegisterEvents(System.Web.UI.WebControls.GridView gridView, GridViewDataBind dataBind, string[] pageText) {
            RegisterEvents(gridView, dataBind, pageText, true);
        }

        /**//// <summary>
        /// 给指定的GridView控件添加RowCommand、RowCreated、PageIndexChanged事件
        /// </summary>
        /// <param name="gridView">需要注册事件的GridView控件</param>
        /// <param name="dataBind">数据绑定方法</param>
        /// <param name="autoChangePage">是否自动添加点击页码的相应事件</param>
        public static void RegisterEvents(System.Web.UI.WebControls.GridView gridView, GridViewDataBind dataBind, bool autoChangePage) {
            RegisterEvents(gridView, dataBind, null, autoChangePage);
        }

        /**//// <summary>
        /// 给指定的GridView控件添加RowCommand、RowCreated、PageIndexChanged事件
        /// </summary>
        /// <param name="gridView">需要注册事件的GridView控件</param>
        /// <param name="dataBind">数据绑定方法</param>
        /// <param name="pageText">翻页按钮上的文字</param>
        /// <param name="autoChangePage">是否自动添加点击页码的相应事件</param>
        public static void RegisterEvents(System.Web.UI.WebControls.GridView gridView, GridViewDataBind dataBind, string[] pageText, bool autoChangePage) {
            gridView.RowCommand += delegate(object sender, GridViewCommandEventArgs e) {
                RowCommand(sender, e, dataBind);
            };
            gridView.RowCreated += delegate(object sender, GridViewRowEventArgs e) {
                RowCreated(sender, e, pageText);
            };
            if (autoChangePage) {
                gridView.PageIndexChanging += delegate(object sender, GridViewPageEventArgs e) {
                    gridView.PageIndex = e.NewPageIndex;
                    if (dataBind != null) {
                        dataBind();
                    } else {
                        gridView.DataBind();
                    }
                };
            }
        }

        /**//// <summary>
        /// 点击每行触发的命令，自动绑定。用于自定义数据绑定方法写在if(!Page.IsPostBack){}外。
        /// </summary>
        public static void RowCommand(object sender, GridViewCommandEventArgs e) {
            RowCommand(sender, e, null);
        }

        /**//// <summary>
        /// 点击每行触发的命令，需提供数据绑定方法。用于自定义数据绑定方法写在if(!Page.IsPostBack){}内。
        /// </summary>
        /// <param name="function">数据绑定方法</param>
        public static void RowCommand(object sender, GridViewCommandEventArgs e, GridViewDataBind dataBind) {
            System.Web.UI.WebControls.GridView _grid = (System.Web.UI.WebControls.GridView)sender;
            SetPageIndex(_grid, e.CommandName);
            if (dataBind != null) {
                dataBind();
            } else {
                _grid.DataBind();
            }
        }

        /**//// <summary>
        /// 增加首页、上页、下页、尾页按钮
        /// </summary>
        public static void RowCreated(object sender, GridViewRowEventArgs e) {
            RowCreated(sender, e, null);
        }

        /**//// <summary>
        /// 增加首页、上页、下页、尾页按钮
        /// </summary>
        /// <param name="buttonText">按钮上的文字。索引：0 首页 1 上页 2 下页 3 尾页</param>
        public static void RowCreated(object sender, GridViewRowEventArgs e,string[] buttonText) {
            if(e.Row.RowType == DataControlRowType.Pager) {
                System.Web.UI.WebControls.GridView _grid = (System.Web.UI.WebControls.GridView)sender;
                if(_grid.PagerTemplate == null) {
                    _grid.PagerSettings.Mode = PagerButtons.Numeric;

                    int pageIndex = _grid.PageIndex;
                    int pageCount = _grid.PageCount;

                    TableRow objRow = (TableRow)e.Row.Cells[0].Controls[0].Controls[0];
                    TableCell objCell;

                    string[] button = {"首页","上页","下页","尾页"};
                    if(buttonText != null) {
                        for(int i = 0; i < buttonText.Length; i++) {
                            button[i] = buttonText[i];
                        }
                    }

                    bool enabled = true;

                    enabled = pageIndex > 0 ? true : false;

                    // 增加首页、上一页按钮
                    objCell = new TableCell();
                    objCell.Controls.Add(LinkButton(button[0], "Page$First", "", enabled));
                    objRow.Cells.AddAt(0, objCell);

                    objCell = new TableCell();
                    objCell.Controls.Add(LinkButton(button[1], "Page$Prev", "", enabled));
                    objRow.Cells.AddAt(1, objCell);

                    enabled = pageIndex < (pageCount - 1) ? true : false;

                    // 增加尾页、下一页按钮
                    objCell = new TableCell();
                    objCell.Controls.Add(LinkButton(button[2], "Page$Next", "", enabled));
                    objRow.Cells.Add(objCell);

                    objCell = new TableCell();
                    objCell.Controls.Add(LinkButton(button[3], "Page$Last", "", enabled));
                    objRow.Cells.Add(objCell);
                }
            }
        }

        /**//// <summary>
        /// 设置GridView的页索引
        /// </summary>
        /// <param name="command">被单击的按钮的命令</param>
        private static void SetPageIndex(System.Web.UI.WebControls.GridView gridView, string command) {
            switch(command) {
                case "Page$First":
                    gridView.PageIndex = 0;
                    break;
                case "Page$Prev":
                    if(gridView.PageIndex > 0)
                        gridView.PageIndex -= 1;
                    break;
                case "Page$Next":
                    if(gridView.PageIndex < (gridView.PageCount - 1))
                        gridView.PageIndex += 1;
                    break;
                case "Page$Last":
                    gridView.PageIndex = gridView.PageCount - 1;
                    break;
                default:
                    return;
            }
        }

        /**//// <summary>
        /// 一个新的LinkButton对象
        /// </summary>
        /// <param name="text">文本</param>
        /// <param name="cmd">相应命令</param>
        /// <param name="css">Css风格</param>
        /// <param name="enabled">可用</param>
        /// <returns>LinkButton</returns>
        private static LinkButton LinkButton(string text, string cmd, string css, bool enabled) {
            LinkButton button = new LinkButton();
            button.Text = text;
            button.CommandName = cmd;
            button.CssClass = css;
            button.Enabled = enabled;
            button.CausesValidation = false;
            return button;
        }
    }
}