关于数据库动态列呈现的实现方案---创建动态类或为Table添加TableRow

在实际项目中会遇见很多复杂条件查询，返回的数据没有专门的实体类与之对应，也无从对应，有些情况返回的列都是不固定的。这个时候数据的呈现就显得比较麻烦，没关系，这里提供两种解决方案：创建动态类，以arraylist返回，或直接创建tableRow添加到table中

 

创建动态类：

using System; using System.Configuration; 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; using System.Reflection; using System.Reflection.Emit; using System.Collections; using System.Collections.Generic; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { this.GridView2.DataSource = GenDataSource(); this.GridView2.DataBind(); } } private ArrayList GenDataSource() { AppDomain ad = System.Threading.Thread.GetDomain(); AssemblyBuilder assBuilder = ad.DefineDynamicAssembly(this.GetType().Assembly.GetName(), AssemblyBuilderAccess.Run); ModuleBuilder modBuilder = assBuilder.DefineDynamicModule("MyModule"); TypeBuilder typBuilder = modBuilder.DefineType("Student", TypeAttributes.Public | TypeAttributes.Class); Dictionary<string,string> proDatas=new Dictionary<string,string>(); proDatas.Add("id","System.Int32"); proDatas.Add("stuNo","System.String"); proDatas.Add("stuName","System.String"); this.GenProperty(typBuilder, proDatas); Type t=typBuilder.CreateType(); object data1 = Activator.CreateInstance(t); t.InvokeMember("Id", BindingFlags.SetProperty, null, data1, new object[] { 1 }); t.InvokeMember("StuNo", BindingFlags.SetProperty, null, data1, new object[] { "1001" }); t.InvokeMember("StuName", BindingFlags.SetProperty, null, data1, new object[] { "Tom" }); object data2 = Activator.CreateInstance(t); t.InvokeMember("Id", BindingFlags.SetProperty, null, data2, new object[] { 2 }); t.InvokeMember("StuNo", BindingFlags.SetProperty, null, data2, new object[] { "1002" }); t.InvokeMember("StuName", BindingFlags.SetProperty, null, data2, new object[] { "Jack" }); ArrayList al = new ArrayList(); al.Add(data1); al.Add(data2); return al; } private void GenProperty(TypeBuilder myTypeBuilder, Dictionary<string,string> proDatas) { foreach (KeyValuePair<string,string> proData in proDatas) { FieldBuilder fieBuilder = myTypeBuilder.DefineField(proData.Key, Type.GetType(proData.Value), FieldAttributes.Private); //FieldBuilder fieBuilder2 = typBuilder.DefineField("stuNo", Type.GetType("System.String"), FieldAttributes.Private); //FieldBuilder fieBuilder3 = typBuilder.DefineField("stuName", Type.GetType("System.String"), FieldAttributes.Private); string proName = proData.Key.Substring(0, 1).ToUpper() + proData.Key.Substring(1); PropertyBuilder custNamePropBldr = myTypeBuilder.DefineProperty(proName, PropertyAttributes.HasDefault, Type.GetType(proData.Value), null); // The property set and property get methods require a special // set of attributes. MethodAttributes getSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig; // Define the "get" accessor method for CustomerName. MethodBuilder custNameGetPropMthdBldr = myTypeBuilder.DefineMethod("get_" + proName, getSetAttr, Type.GetType(proData.Value), Type.EmptyTypes); ILGenerator custNameGetIL = custNameGetPropMthdBldr.GetILGenerator(); custNameGetIL.Emit(OpCodes.Ldarg_0); custNameGetIL.Emit(OpCodes.Ldfld, fieBuilder); custNameGetIL.Emit(OpCodes.Ret); // Define the "set" accessor method for CustomerName. MethodBuilder custNameSetPropMthdBldr = myTypeBuilder.DefineMethod("set_" + proName, getSetAttr, null, new Type[] { Type.GetType(proData.Value) }); ILGenerator custNameSetIL = custNameSetPropMthdBldr.GetILGenerator(); custNameSetIL.Emit(OpCodes.Ldarg_0); custNameSetIL.Emit(OpCodes.Ldarg_1); custNameSetIL.Emit(OpCodes.Stfld, fieBuilder); custNameSetIL.Emit(OpCodes.Ret); // Last, we must map the two methods created above to our PropertyBuilder to // their corresponding behaviors, "get" and "set" respectively. custNamePropBldr.SetGetMethod(custNameGetPropMthdBldr); custNamePropBldr.SetSetMethod(custNameSetPropMthdBldr); } } }

这里只是一个创建的示例，当然，有朋友肯定会问到，那对于操作列（编辑，删除，查看等）如何处理，关于这个问题，在以前的文章中已经做了解决，请参考：http://blog.youkuaiyun.com/Rock870210/archive/2009/11/26/4880533.aspx    关于Gridview自动生成列后，手动设定的模板列位置问题解决方案

这个是关于创建动态类的示例，下面再看看使用tablerow的示例：

aspx页面：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!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>无标题页</title> </head> <body> <form id="form1" runat="server"> <div class="mainDiv"> <asp:Table ID="Table1" runat="server"> </asp:Table> <asp:Button ID="Button1" runat="server" Text="Button" /> </div> </form> </body> </html>

这里只是放入一个服务器控件Table

在看看后台代码：

using System; using System.Data; using System.Configuration; 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; using SySoft.BusinessLogicLayer; using SySoft.Models; using System.Collections.Generic; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { BindStudents(); } private void BindStudents() { List<StudentInfo> students = StudentManager.SelectAll(); #region 添加标题行 TableRow titleRow = new TableRow(); TableCell idTitleCell = new TableCell(); idTitleCell.CssClass = "title"; idTitleCell.Text = "编号"; idTitleCell.Width = Unit.Pixel(100); titleRow.Cells.Add(idTitleCell); TableCell nameTitleCell = new TableCell(); nameTitleCell.CssClass = "title"; nameTitleCell.Text = "姓名"; nameTitleCell.Width = Unit.Pixel(100); titleRow.Cells.Add(nameTitleCell); List<PropertyInfo> properties = PropertyManager.SelectAll(); int titileCellWidth = 300 / (properties.Count + 1); foreach (PropertyInfo property in properties) { TableCell titleCell = new TableCell(); titleCell.CssClass = "title"; titleCell.Text = property.Pro_Name; titleCell.Width = Unit.Pixel(titileCellWidth); titleRow.Cells.Add(titleCell); } TableCell optCell = new TableCell(); optCell.CssClass = "title"; optCell.Text = "操作"; optCell.Width = Unit.Pixel(100); titleRow.Cells.Add(optCell); this.Table1.Rows.Add(titleRow); #endregion #region 添加数据行 List<Student_DataInfo> datas = Student_DataManager.SelectAll(); foreach (StudentInfo student in students) { TableRow row = new TableRow(); TableCell idCell = new TableCell(); idCell.Text = student.Stu_Id.ToString(); row.Cells.Add(idCell); TableCell nameCell = new TableCell(); nameCell.Text = student.Stu_Name; row.Cells.Add(nameCell); foreach (PropertyInfo property in properties) { TableCell cell = new TableCell(); stu_id = student.Stu_Id; pro_id = property.Pro_Id; Student_DataInfo selectedData = datas.Find(this.FindStudentData); if (selectedData == null) continue; cell.Text = selectedData.Data; row.Cells.Add(cell); } optCell = new TableCell(); HyperLink hl = new HyperLink(); hl.Text = "编辑"; hl.NavigateUrl = "StudentDetails.aspx?stuid=" + student.Stu_Id.ToString(); optCell.Controls.Add(hl); row.Cells.Add(optCell); this.Table1.Rows.Add(row); } #endregion } int stu_id; int pro_id; private bool FindStudentData(Student_DataInfo item) { return item.Stu_Id == stu_id && item.Pro_Id == pro_id; } }

当然有人会说List<StudentInfo> students = StudentManager.SelectAll();
这里的实体类都不确定，怎么用List<>集合啊？当然，这只是个例子，数据可以使用dataset返回，使用dataset后修改的代码就不用我再写了吧！

 

早就说把这个帖子发上来，一直拖到今天，嘿嘿！希望对大家有帮助！