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  • asp.net自定义控件

      这段时间一直想自己做个控件玩玩,原本准备做一个像repeater差不多 当然最初的设想用起来要比repeater方便,包括在CSS和一些JS,jquery的使用上面

    和repeater进行对比,但是做出来后发现代码绕了好多,控件直接读取数据库的话还要封装好读取数据库的代码,如果不封装在后期的使用过程中会对整个项目都必

    定会有很多的约束。虽然这是个偏离原来目的的控件,但是对于初学者来说 应该还有参考价值。

    下面贴出控件代码:

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Linq;
    using System.Text;
    using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Configuration;
    using System.Drawing.Printing;
    using System.IO;
    using System.Data;
    using System.Data.SqlClient;
    
    [assembly: TagPrefix("XTB_MSList", "XXW")]
    namespace XTB_MSList
    {
        [DefaultProperty("Text")]
        [ToolboxData("<{0}:XTB_MSList runat=server></{0}:XTB_MSList>")]
    
        public class XTB_MMSList : WebControl
        {
            #region Text属性
            [Bindable(true)]
            [Category("Appearance")]
            [DefaultValue("")]
            [Localizable(true)]
            public string Text
            {
                get
                {
                    String s = (String)ViewState["Text"];
                    return ((s == null) ? "[" + this.ID + "]" : s);
                }
                set
                {
                    ViewState["Text"] = value;
                }
            }
            #endregion
    
            #region 读取的表名称
            public string Xtb_Name
            {
                get
                {
                    String s = (String)ViewState["Xtb_Name"];
                    return ((s == null) ? "[" + this.ID + "]" : s);
                }
                set
                {
                    ViewState["Xtb_Name"] = value;
                }
            }
            #endregion
    
            #region 读取的HTML页面地址
            public string Xtb_PathName
            {
                get
                {
                    String s = (String)ViewState["Xtb_PathName"];
                    return ((s == null) ? "[" + this.ID + "]" : s);
                }
                set
                {
                    ViewState["Xtb_PathName"] = value;
                }
            }
            #endregion
    
            #region 读取数据库连接字符串的名称
            public string Xtb_DName
            {
                get
                {
                    String s = (String)ViewState["Xtb_DName"];
                    return ((s == null) ? "[" + this.ID + "]" : s);
                }
                set
                {
                    ViewState["Xtb_DName"] = value;
                }
            }
            #endregion
    
            #region 读取显示的行数
            public string Xtb_Count
            {
                get
                {
                    String s = (String)ViewState["Xtb_Count"];
                    return ((s == null) ? "[" + this.ID + "]" : s);
                }
                set
                {
                    ViewState["Xtb_Count"] = value;
                }
            }
            #endregion
    
            protected override void RenderContents(HtmlTextWriter output)
            {
                if (!DesignMode)
                {
                    string connectString = ConfigurationManager.ConnectionStrings[Xtb_DName].ConnectionString;
                    string htmls = GetInterIDList(Xtb_PathName);
                    string outprint = DataListPrint(connectString, htmls);
                    output.Write(outprint);
                }
                base.RenderContents(output);
            }
            /// <summary>
            /// 读取数据库,显示数据替换字符串输出到页面上
            /// </summary>
            /// <param name="connectString">数据库连接字符串</param>
            /// <param name="htmls">静态页面的内容</param>
            public string DataListPrint(string connectString, string htmls)
            {
                string outprint = "";
                var listName = TableList(htmls);
                char[] sp = { ','};
                string[] listname = listName.Split(sp);
                string listkey = "";
                for (int i = 0; i < listname.Length; i++)
                {
                    listkey = listkey + listname[i].ToString() + ",";
                }
                listkey = listkey.Substring(0, listkey.Length - 1);
                string outhtmls = "";
                if (listkey.Length > 1)
                {
                    DataTable dt = DBHelp.GetDataTable("select top " + Xtb_Count + " " + listkey + " from " + Xtb_Name, connectString);
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        for (int j = 0; j < listname.Length; j++)
                        {
                            if (j==0)
                                outhtmls = htmls.Replace("{XTB_" + listname[j] + "}", dt.Rows[i][listname[j].ToString()].ToString());
                            else
                                outhtmls = outhtmls.Replace("{XTB_" + listname[j] + "}", dt.Rows[i][listname[j].ToString()].ToString());
                        }
                        outprint = outprint + outhtmls ;
                    }
                }
                return outprint;
            }
            /// <summary>
            /// 提取前台要显示的字段名称,并返回LIST
            /// </summary>
            /// <param name="htmls">静态页面内容转化成的字符串</param>
            /// <returns>返回值 查询的字段数组</returns>
            public string TableList(string htmls)
            {
                string ListName = "";
                int i = htmls.IndexOf("{XTB_");
                string s = htmls.Substring(i, htmls.Length - i);
                for (int l = 0; s.IndexOf("{XTB_") != -1; l++)
                {
                    i = s.IndexOf("{XTB_");
                    s = s.Substring(i, s.Length - i);
                    string key = s.Substring(5, s.IndexOf("}") - 5);
                    i = s.IndexOf("{XTB_");
                    s = s.Substring(i + 5, s.Length - i - 5);               
                    ListName += key + ",";
                }        
                ListName = ListName.Substring(0, ListName.Length - 1);
                return ListName;
            }
            /// <summary>
            /// 读取html静态页面
            /// </summary>
            /// <param name="strfile">页面名称或地址路径Xtb_PathName的属性值</param>
            /// <returns>返回值 静态页面内容</returns>
            public string GetInterIDList(string strfile)
            {
                string strout = "";
                if (File.Exists(System.Web.HttpContext.Current.Server.MapPath(strfile)))
                {                
                    StreamReader sr = new StreamReader(System.Web.HttpContext.Current.Server.MapPath(strfile), System.Text.Encoding.Default);
                    String input = sr.ReadToEnd();
                    sr.Close();
                    strout = input;
                }
                return strout;
            }
        }
    }

    控件代码就到此结束,下面讲解使用过程:

    需要使用控件时要先把生成的DLL文件引用到项目中去,

    页面使用时需要输入如下代码<XXW:XTB_MMSList runat="server" Xtb_Count="5" Xtb_DName="SQLConnString" Xtb_Name="orders" Xtb_PathName="TEST.html" />

    还有<%@ Register Assembly="XTB_MSList" Namespace="XTB_MSList" TagPrefix="XXW" %>

    然后在Web.config文件中添加数据库连接字符串,连接字符串的name可以随意命名,示例:

        <connectionStrings>
            <add name="SQLConnString" connectionString="Data Source=.;Initial Catalog=Northwind;integrated security=true" providerName="System.Data.SqlClient;Pooling=true;MAX Pool Size=512;Min Pool Size=50;Connection Lifetime=300"/>
        </connectionStrings>

    aspx页面代码示例:

    <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2"%>
    
    <%@ Register Assembly="XTB_MSList" Namespace="XTB_MSList" TagPrefix="XXW" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
        <title></title>
    </head>
    <body>
        <form id="form1" runat="server">
        <div>
        <XXW:XTB_MMSList  runat="server" Xtb_Count="5" Xtb_DName="SQLConnString" Xtb_Name="orders" Xtb_PathName="TEST.html" />
        </div>
        </form>
    </body>
    </html>

    根据aspx页面中自定义控件的Xtb_PathName="TEST.html" 在项目或相应的位置处添加文件test.html,在这里也可以设置成test.txt。只需要文件存在就

    可以读取然后显示在页面上,也可以在这里设置好CSS,显示的时候会直接输出在页面上;

    下面贴出test.html的代码:

    <div>
        {XTB_CustomerID}
    </div>
    <div>
        {XTB_OrderDate}
    </div>
    <div>
        {XTB_ShippedDate}
    </div>

    下面贴出我的测试页面输出后显示的代码如下:

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head><title>
    
    </title></head>
    <body>
        <form method="post" action="Default2.aspx" id="form1">
    <div class="aspNetHidden">
    <input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwUKLTYyNzE4MTUzN2RkJXbGr7tDft0VFyhd4U01D5uCJLGK9q/ycTM2X8SWPnw=" />
    </div>
    
        <div>
        <span><div>
        VINET
    </div>
    <div>
        1996-7-4 0:00:00
    </div>
    <div>
        1996-7-16 0:00:00
    </div>
    <br><div>
        TOMSP
    </div>
    <div>
        1996-7-5 0:00:00
    </div>
    <div>
        1996-7-10 0:00:00
    </div>
    <br><div>
        HANAR
    </div>
    <div>
        1996-7-8 0:00:00
    </div>
    <div>
        1996-7-12 0:00:00
    </div>
    <br><div>
        VICTE
    </div>
    <div>
        1996-7-8 0:00:00
    </div>
    <div>
        1996-7-15 0:00:00
    </div>
    <br><div>
        SUPRD
    </div>
    <div>
        1996-7-9 0:00:00
    </div>
    <div>
        1996-7-11 0:00:00
    </div>
    <br></span>
        </div>
        </form>
    </body>
    </html>

    从代码可以看到控件的标签已经不存在,全部转化为要读取的数据显示在页面上。所以可以看做这个控件归根究底就是一种字符的替换,替换了原先的字符显示在

    页面上。只是省去了中间的代码,当然 ,替换的代码也已经都封装在控件中。

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  • 原文地址:https://www.cnblogs.com/xuxw/p/3416619.html
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