DataList分页

容易么我, DataList分页在网上找了N个例子,分了三天,经历了N多挫折,心情从低谷到高山,又从高山到低谷,快弄出精神病了,好在有很多朋友帮忙,总算弄出来了,总结了下,发现N多的挫折竟然都是些很基础的知识,感叹啊,想提高快点真是要一步一个脚印,扎扎实实的.把代码贴出来,给以后要用留点参考.

后台:

 protected void Page_Load(object sender, EventArgs e)
    ...{
        if (!IsPostBack)
        ...{
            panel1.Visible = true;

            this.Session["tid"] = "";

            GetDataBind("select * from land_showimages");

            CurrentPage = 0;
            ViewState["PageIndex"] = 0;
            //计算总共有多少记录
            RecordCount = CalculateRecord("");
            lblRecordCount.Text = RecordCount.ToString();
            //计算总共有多少页

            if (RecordCount % PageSize != 0)
            ...{
                PageCount = RecordCount / PageSize + 1;
            }
            else
            ...{
                PageCount = RecordCount / PageSize;
            }

            lblPageCount.Text = (PageCount).ToString();
            ViewState["PageCount"] = PageCount;
            myDropDownList.Items.Clear();
            DropDown();
        }
    }

    int PageSize = 6, RecordCount, PageCount, CurrentPage;

    private void GetDataBind(string sql)
    ...{
        int StartIndex;
        //设定导入的起终地址
        StartIndex = CurrentPage * PageSize;

        DataSet ds = new DataSet();

        OracleConnection conn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        conn.Open();

        OracleCommand comm = new OracleCommand();
        comm.Connection = conn;
        comm.CommandText = sql;
        comm.CommandType = CommandType.Text;

        OracleDataAdapter myda = new OracleDataAdapter();
        myda.SelectCommand = comm;

        myda.Fill(ds, StartIndex, PageSize, "land_showimages");


        MyDataGrid.DataSource = ds.Tables["land_showimages"].DefaultView;
        MyDataGrid.DataBind();

        lbnFirstPage.Enabled = true;
        lbnNextPage.Enabled = true;
        lbnPrevPage.Enabled = true;
        lbnLastPage.Enabled = true;

        if (CurrentPage == (PageCount - 1))
        ...{
            lbnLastPage.Enabled = false;
            lbnNextPage.Enabled = false;
        }
        if (CurrentPage == 0)
        ...{
            lbnFirstPage.Enabled = false;
            lbnPrevPage.Enabled = false;
        }

        if (PageCount == 1)
        ...{
            lbnFirstPage.Enabled = false;
            lbnNextPage.Enabled = false;
            lbnPrevPage.Enabled = false;
            lbnLastPage.Enabled = false;
        }
        lblCurrentPage.Text = (CurrentPage + 1).ToString();
        ViewState["PageIndex"] = CurrentPage;
    }

    public int CalculateRecord(string tid)
    ...{
        int intCount;

        OraAccess ora = new OraAccess();
        DBParaList para = new DBParaList();

        if (tid == "")
        ...{
            intCount = ora.exeCountSql("land_showimages", new DBParaList());
        }
        else
        ...{
            para.AddPara("typeid", tid);
            intCount = ora.exeCountSql("land_showimages", para);
        }
        ora.close();
        return intCount;
    }

    public void Page_OnClick(Object sender, CommandEventArgs e)  //翻页按钮
    ...{
        CurrentPage = (int)ViewState["PageIndex"];
        PageCount = (int)ViewState["PageCount"];

        string cmd = e.CommandName;
        //判断cmd，以判定翻页方向
        switch (cmd)
        ...{
            case "next":
                if (CurrentPage < (PageCount - 1)) CurrentPage++;
                break;
            case "prev":
                if (CurrentPage > 0) CurrentPage--;
                break;
            case "last":
                CurrentPage = PageCount - 1;
                break;
            default:
                CurrentPage = System.Convert.ToInt32(cmd);
                break;
        }
        ViewState["PageIndex"] = CurrentPage;
        myDropDownList.SelectedIndex = CurrentPage;

        if (this.Session["tid"] == "")
        ...{
            GetDataBind("select * from land_showimages");
        }
        else
        ...{
            GetDataBind("select * from land_showimages where typeid='" + this.Session["tid"] + "'");
        }
        panel1.Visible = true;

    }

    private void DropDown()
    ...{
        for (int u = 0; u < PageCount; u++)
        ...{
            myDropDownList.Items.Add(new ListItem("第" + (u + 1).ToString() + "页", Convert.ToString(u)));
        }
    }

    public void listchanged(object sender, System.EventArgs e) //页数下拉框
    ...{
        CurrentPage = myDropDownList.SelectedIndex;

        GetDataBind("select * from land_showimages where typeid='" + this.Session["tid"] + "'");
        panel1.Visible = true;

    }

    public void ddltype_OnSelectedIndexchanged(object sender, System.EventArgs e)  //类别下拉框
    ...{
        string sql;
       
        if (ddltype.SelectedValue == "-1")
        ...{
             sql = string.Format("select * from land_showimages");
             this.Session["tid"] = "";
        }
        else
        ...{
            sql = string.Format("select * from land_showimages where typeid={0}", ddltype.SelectedValue);
            this.Session["tid"] = ddltype.SelectedValue;

        }
  
        GetDataBind(sql);

        panel1.Visible = true;
        CurrentPage = 0;
        ViewState["PageIndex"] = 0;
        //计算总共有多少记录
        RecordCount = CalculateRecord(this.Session["tid"].ToString());
        lblRecordCount.Text = RecordCount.ToString();
        //计算总共有多少页

        if (RecordCount % PageSize != 0)
        ...{
             PageCount = RecordCount / PageSize +1;
        }
        else
        ...{
            PageCount = RecordCount / PageSize;
        }

         lblPageCount.Text = (PageCount).ToString();
        ViewState["PageCount"] = PageCount;
        myDropDownList.Items.Clear();
        DropDown();
    }

前台:

<div style="background-color: #ffffff">
            <asp:DropDownList ID="ddltype" runat="server" AppendDataBoundItems="true" DataSourceID="SDSTYPE"
                AutoPostBack="true" DataTextField="typename" DataValueField="id" Width="105px"
                OnSelectedIndexChanged="ddltype_OnSelectedIndexchanged">
                <asp:ListItem Text="--请选择类别--" Value="-1"></asp:ListItem>
            </asp:DropDownList>
            <asp:SqlDataSource ID="SDSTYPE" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
                ProviderName="<%$ ConnectionStrings:ConnectionString.ProviderName %>" SelectCommand='SELECT "ID", "TYPENAME" FROM "LAND_IMAGETYPE" ORDER BY "TYPENAME"'>
            </asp:SqlDataSource>
            <br />
            <asp:DataList ID="MyDataGrid" runat="server" Width="100%" ItemStyle-VerticalAlign="Top"
                CaptionAlign="Bottom" RepeatColumns="3" Height="320px" RepeatDirection="Horizontal">
                <ItemTemplate>
                    <table width="100%">
                        <tr>
                            <td align="center">
                                <a href="imagesDetail.aspx?id=<%#Eval("id") %>" target="_blank">
                                    <asp:Image ID="Image1" runat="server" ImageUrl='<%# Eval("purl") %>' Width="100"
                                        Height="60" /></a>
                                <br />
                                <asp:Label ID="Label1" runat="server" Text='<%# Eval("imagename") %>' Font-Size="12px"></asp:Label>
                            </td>
                        </tr>
                    </table>
                </ItemTemplate>
            </asp:DataList>
            &nbsp; &nbsp; &nbsp; &nbsp;<asp:Panel ID="panel1" runat="server" Visible="true">
                共有<asp:Label ID="lblRecordCount" ForeColor="red" runat="server" />条记录&nbsp; 当前为<asp:Label
                    ID="lblCurrentPage" ForeColor="red" runat="server" />/
                <asp:Label ID="lblPageCount" ForeColor="red" runat="server" />页&nbsp;
                <asp:LinkButton ID="lbnFirstPage" Text="首 页" CommandName="0" OnCommand="Page_OnClick"
                    runat="server" />
                <asp:LinkButton ID="lbnPrevPage" Text="上一页" CommandName="prev" OnCommand="Page_OnClick"
                    runat="server" />
                <asp:LinkButton ID="lbnNextPage" Text="下一页" CommandName="next" OnCommand="Page_OnClick"
                    runat="server" />
                <asp:LinkButton ID="lbnLastPage" Text="末 页" CommandName="last" OnCommand="Page_OnClick"
                    runat="server" />
                <asp:DropDownList ID="myDropDownList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="listchanged">
                </asp:DropDownList></asp:Panel>
        </div>