In 91

，我的Windows Live Writer又在鬧脾氣了，怎麼發佈都沒有錯誤訊息，文章卻沒上來。只好手動貼了。

今天要介紹的，是怎麼在GridView裡面增加自訂的Pager。

請原諒我是個樣式白癡，我只能提供功能跟作法，樣式就請自行設計對應的css吧。

這邊舉的例子，是新增一個可以自行輸入頁碼的TextBox。有需要增加其他的Control，請照樣造句即可。

Download Source Code：GridViewPager.rar

Step1：

一樣新增一個類別庫叫做Joey，接著新增一個類別叫做JoeyGridView.cs並繼承GridView，

這邊我偷懶匯入了Microsoft.VisualBasic NameSpace，因為裡面有需要用到判斷數字，實在懶得自己寫function，就直接用VB內建的IsNumeric()了。

如果不想匯入VB的話，可以參考mis2000Lab大大的文章，[C#]以前在VB語法裡面用慣的 IsNumeric，在C#不見了？？，主要還是使用Double.Tryparse()的function，

如果不是double，就自己選用適用的型別吧。

using ...System;
using System.Collections.Generic;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.VisualBasic;
namespace Joey
...{
    public class JoeyGridView: GridView
    ...{
    }
}

Step2：

接著要覆寫的是OnRowCreated()，當e.row為Pager的時候，我們要插入自訂的Pager。

        Override Method#region Override Method
        /**//// <summary>
        /// 引發 <see cref="E:System.Web.UI.WebControls.GridView.RowCreated"/> 事件，並加入自訂的pager。
        /// </summary>
        /// <param name="e"><see cref="T:System.Web.UI.WebControls.GridViewRowEventArgs"/> 包含事件資料。</param>
        protected override void OnRowCreated(GridViewRowEventArgs e)
        ...{
            base.OnRowCreated(e);
            if (e.Row.RowType == DataControlRowType.Pager)
            ...{ SettingPager(e.Row); }

        }
        #endregion

Step3：

再來就是精髓所在了，我們自訂Pager，要用TableRow的方式，插入原本的Pager裡。

並自訂新增Control的相關事件出來。

Private method:CreatePager#region Private method:CreatePager
        /**//// <summary>
        /// Settings the pager.
        /// </summary>
        /// <param name="gridRow">The grid row.</param>
        private void SettingPager(GridViewRow gridRow)
        ...{
            TableCell newCell = new TableCell();
            TableRow tableRow = new TableRow();
            newCell = CreatePagerTextBox();
            tableRow = GetPagerTableRow(gridRow.Cells[0]);
            tableRow.Cells.Add(newCell);
        }

        /**//// <summary>
        /// Gets the pager's tablerow.
        /// </summary>
        /// <param name="gridRowCell">The grid row cell.</param>
        /// <returns></returns>
        private TableRow GetPagerTableRow(Control gridRowCell)
        ...{
            TableRow row = null;
            while (gridRowCell.Controls.Count > 0)
            ...{
                row = gridRowCell as TableRow;
                if (row != null)
                ...{
                    break;
                }
                gridRowCell = gridRowCell.Controls[0];
            }
            return row;
        }

        /**//// <summary>
        /// Creates text box in Grid pager .
        /// </summary>
        /// <returns></returns>
        private TableCell CreatePagerTextBox()
        ...{
            TextBox sel = new TextBox();
            sel.ID = "PageSizeSelector3";
            sel.Text = Convert.ToString(this.PageIndex + 1);
            sel.AutoPostBack = true;
            sel.EnableViewState = true;
            sel.Width = new Unit(30, UnitType.Pixel);

            sel.TextChanged += new EventHandler(PageChangeSelectorByTextBox_Clicked);

            TableCell newCell = new TableCell();
            newCell.HorizontalAlign = HorizontalAlign.Right;
            newCell.Controls.Add(sel);
            return newCell;
        }
        #endregion

Step4：

最後是對Pager自訂事件的處理，這裡我們做三件事。

• 當輸入的值非數字時，維持原pageindex。
• 當輸入值>PageCount時，移至最後頁。
• 當輸入值比0小時，移至第一頁。

        Custom Event#region Custom Event
        public event EventHandler PageIndexByTextChanged;
        /**//// <summary>
        /// Handles the Clicked event of the PageChangeSelectorByTextBox control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
        /// <remarks>當輸入的值非數字時，維持原pageindex。
        /// 當輸入值>PageCount時，移至最後頁。
        /// 當輸入值比0小時，移至第一頁</remarks>
        private void PageChangeSelectorByTextBox_Clicked(object sender, System.EventArgs e)
        ...{
            if (PageIndexByTextChanged != null)
            ...{
                TextBox ddl = (TextBox)sender;
                string requestedPageSize = ddl.Text;
                GridView grid = this;
                try
                ...{
                    if (Information.IsNumeric(requestedPageSize) & requestedPageSize.IndexOf(".") == -1)
                    ...{
                        int intrequestedPageSize = Convert.ToInt32(requestedPageSize);
                        if (intrequestedPageSize == 0)
                        ...{
                            ddl.Text = Convert.ToString(grid.PageIndex + 1);
                        }
                        else if (intrequestedPageSize <= grid.PageCount && intrequestedPageSize > 0)
                        ...{

                            grid.PageIndex = intrequestedPageSize - 1;
                        }
                        else if (intrequestedPageSize > grid.PageCount)
                        ...{

                            grid.PageIndex = grid.PageCount - 1;
                            ddl.Text = Convert.ToString(grid.PageCount);
                        }
                        if (PageIndexByTextChanged != null)
                        ...{
                            PageIndexByTextChanged(sender, e);
                        }
                    }
                    else
                    ...{
                        ddl.Text = Convert.ToString(grid.PageIndex + 1);
                    }
                }
                catch (Exception ex)
                ...{
                    ddl.Text = Convert.ToString(grid.PageIndex + 1);
                }
            }
        }
        #endregion      

    }

Step5：

就這樣，大功告成。當然這樣的Code還是有美中不足的地方。

就是在TextChanged事件觸發的部分，還是需要額外自己寫Code去做Grid.DataBind()的動作。(跟原生的GridView.PageIndexChanging一樣)

如果有大大可以指導一下怎麼連那一段Code都省下來，小弟在這感激不盡！

建置一下類別庫，產生Joey.dll，加進網站參考裡，在頁面上拉一個JoeyGridView進來。

餵資料給GridView之後，還需額外撰寫事件重bind Grid的資料。（這邊樣式是套GridView的智慧標籤）

aspx：

cs：資料我就隨便塞了，請原諒我的懶惰。

using ...System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class JoeyGridViewTest : System.Web.UI.Page
...{
    private DataTable _dtDt = new DataTable();
    protected void Page_Load(object sender, EventArgs e)
    ...{
        _dtDt.Columns.Add("Text");
        _dtDt.Columns.Add("Value");
        _dtDt.Columns.Add("CreatedDate");


        _dtDt.Rows.Add(new string[] ...{ "萬華區", "萬華", "2003/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "中正區", "中正", "2003/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "大同區", "大同", "2005/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "台中市", "台中", "2005/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "大甲鎮", "大甲", "2007/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "台南市", "台南", "2007/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "台北市", "北", "2007/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "台中縣", "中", "2007/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "台南縣", "南", "2010/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "萬華區", "萬華", "2010/01/01" });
        _dtDt.Rows.Add(new string[] ...{ "中正區", "中正", "2010/01/01" });

        if (!IsPostBack)
        ...{
            this.ViewState["source"] = _dtDt;
            this.JoeyGridView1.DataSource = _dtDt;
            this.JoeyGridView1.DataBind();
        }
    }
    protected void JoeyGridView1_PageIndexByTextChanged(object sender, EventArgs e)
    ...{
        this.JoeyGridView1.DataSource = this.ViewState["source"];
        string pageindex= ((TextBox)sender).Text;
        this.JoeyGridView1.PageIndex = Convert.ToInt32(pageindex) - 1;
        this.JoeyGridView1.DataBind();
    }

    protected void JoeyGridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    ...{
        this.JoeyGridView1.DataSource = this.ViewState["source"];
        this.JoeyGridView1.PageIndex = e.NewPageIndex;
        this.JoeyGridView1.DataBind();
    }
}

(忘記插上結果畫面…真的老了)

最後感謝mis2000lab大大的判斷C#自訂IsNumeric的文章。

我相信我這個自訂Pager的作法一定還有很大的改進空間，希望拋磚引玉一下，能有高手或其他大大們給予更多的建議。

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