关于asp.net DataGrid 重新封装代码？

Question

 不好意思，代码如下：
 public class HVDDataGrid : DataGrid, INamingContainer
{        private System.Web.UI.WebControls.DataGrid datagrid = new DataGrid();
/// <summary> 
/// 将此控件呈现给指定的输出参数。
/// </summary>
/// <param name="output"> 要写出到的 HTML 编写器 </param>
protected override void Render(HtmlTextWriter writer)
{
AddAttributesToRender(writer);
           
LiteralControl l = new LiteralControl("");
l.RenderControl(writer);
            for (int ii = 0; ii < thecel().Length; ii++)
            {
                BoundColumn tm = new BoundColumn();
                tm.HeaderText = thecel()[ii];
                tm.DataField = thecel()[ii];
                datagrid.Columns.Add(tm);
                DataBind();
            }
            datagrid.RenderControl(writer);
}
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
        }
        public override void DataBind()
        {
            datagrid.DataBind();
        }                public override object DataSource
        {
            get
            {
                return this.datagrid.DataSource;
            }
            set
            {
                this.datagrid.DataSource = value;
            }        }
       
        public override DataGridColumnCollection  Columns
        {
            get 
            { 
             return base.Columns;
            }
        }
      
        public override bool AutoGenerateColumns
        {
            get
            {
                return datagrid.AutoGenerateColumns;
            }
            set
            {
                datagrid.AutoGenerateColumns = value;
                
            }
        }        public string[] thecel()
        {
            return cells.Split(',');
        }        private string _cells="";
        public String cells
        {
            get { return _cells; }
            set { _cells = value; }
        }   
        
}

Answer 1

private string _cells=""; 
        public String cells 
        { 
            get { return _cells; } 
            set { _cells = value; } 
        }  
===============
       
 public String cells 
        { 
            get { return ViewState["cells"]!=null?ViewState["cells"]:String.Empty; } 
            set { ViewState["cells"]= value; } 
        }  ==========
自定义属性建议用视图状态，不然你的属性状态怎么保存？

Answer 2

还有就是楼主既然继承了DataGrid，为什么还要实例化一个DataGrid？
private System.Web.UI.WebControls.DataGrid datagrid = new DataGrid(); 

Answer 3

复合控件的做法，应该是重载CreateChildControls，然后在里面进行实例化，然后设置ChildControlsCreated 属性为true避免重复生成控件，提高性能，使用的时候，先用EnsureChildControls方法检测控件是否生成
=====================using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;namespace CustomControls
{
    public class HVDDataGrid : DataGrid, INamingContainer
    {        private System.Web.UI.WebControls.DataGrid datagrid ;
        /// <summary> 
        /// 将此控件呈现给指定的输出参数。 
        /// </summary> 
        /// <param name="output"> 要写出到的 HTML 编写器 </param> 
        protected override void Render(HtmlTextWriter writer)
        {
            EnsureChildControls();//使用控件前，先检测控件是否已经生成，避免“未将对象设置引用对象的实例”的错误
            AddAttributesToRender(writer);            LiteralControl l = new LiteralControl("");
            l.RenderControl(writer);
            for (int ii = 0; ii < thecel().Length; ii++)
            {
                BoundColumn tm = new BoundColumn();
                tm.HeaderText = thecel()[ii];
                tm.DataField = thecel()[ii];
                datagrid.Columns.Add(tm);
                DataBind();
            }
            datagrid.RenderControl(writer);
        }
        protected override void CreateChildControls()
        {
            datagrid = new DataGrid();
            this.Controls.Add(datagrid);
              base.CreateChildControls();
            ChildControlsCreated = true;//避免重复生成控件        }
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
        }
        public override void DataBind()
        {
            datagrid.DataBind();
        }        public override object DataSource
        {
            get
            {
                return this.datagrid.DataSource;
            }
            set
            {
                this.datagrid.DataSource = value;
            }        }        public override DataGridColumnCollection Columns
        {
            get
            {
                return base.Columns;
            }
        }        public override bool AutoGenerateColumns
        {
            get
            {
                return datagrid.AutoGenerateColumns;
            }
            set
            {
                datagrid.AutoGenerateColumns = value;            }
        }        public string[] thecel()
        {
            return cells.Split(',');
        }        public String cells
        {
            get { return ViewState["cells"] != null ? (string)ViewState["cells"] : String.Empty; }
            set { ViewState["cells"] = value; } 
        }    }
}

Answer 4

楼主，我给你改好了，设计时支持也有了，AutoGenerateColumns的属性的错误也解决了，记得给分^_^
=============using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;namespace CustomControls
{
    public class HVDDataGrid : DataGrid, INamingContainer
    {        private System.Web.UI.WebControls.DataGrid datagrid ;
        /// <summary> 
        /// 将此控件呈现给指定的输出参数。 
        /// </summary> 
        /// <param name="output"> 要写出到的 HTML 编写器 </param> 
        protected override void Render(HtmlTextWriter writer)
        {
            EnsureChildControls();//使用控件前，先检测控件是否已经生成，避免“未将对象设置引用对象的实例”的错误
            AddAttributesToRender(writer);            LiteralControl l = new LiteralControl("");
            l.RenderControl(writer);
            for (int ii = 0; ii < thecel().Length; ii++)
            {
                BoundColumn tm = new BoundColumn();
                tm.HeaderText = thecel()[ii];
                tm.DataField = thecel()[ii];
                datagrid.Columns.Add(tm);
                DataBind();
            }
            datagrid.RenderControl(writer);
        }
        protected override void CreateChildControls()
        {
            datagrid = new DataGrid();
            this.Controls.Add(datagrid);
            ChildControlsCreated = true;//避免重复生成控件
            base.CreateChildControls();
        }
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
        }
        public override void DataBind()
        {
            datagrid.DataBind();
        }        public override object DataSource
        {
            get
            {
                return this.datagrid.DataSource;
            }
            set
            {
                this.datagrid.DataSource = value;
            }        }        public override DataGridColumnCollection Columns
        {
            get
            {
                return base.Columns;
            }
        }        public override bool AutoGenerateColumns
        {
            get
            {
                EnsureChildControls();
                return datagrid.AutoGenerateColumns;
            }
            set
            {
                EnsureChildControls();
                datagrid.AutoGenerateColumns = value;            }
        }        public string[] thecel()
        {
            return cells.Split(',');
        }        public String cells
        {
            get { return ViewState["cells"] != null ? (string)ViewState["cells"] : String.Empty; }
            set { ViewState["cells"] = value; } 
        }    }
}

Answer 5

使用示例：<FW:HVDDataGrid ID="HVDDataGrid1" runat="server" AutoGenerateColumns="false" cells="UserID,UserName">
        <Columns>
        <asp:TemplateColumn>
        <ItemTemplate>
        <%#DataBinder.Eval(Container.DataItem,"UserID") %>
        
</ItemTemplate>
        </asp:TemplateColumn>
        <asp:TemplateColumn>
        <ItemTemplate>
        <%#DataBinder.Eval(Container.DataItem,"UserID") %>
        
</ItemTemplate>
        </asp:TemplateColumn>
        </Columns>
        </FW:HVDDataGrid>
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;
using System.Data.SqlClient;
public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindGrid();
        }
    }    private void BindGrid()
    {
        DataTable dt = new DataTable();
        DataColumn dc1 = new DataColumn("UserID", Type.GetType("System.Int32"));
        DataColumn dc2 = new DataColumn("UserName", Type.GetType("System.String"));
        dt.Columns.Add(dc1);
        dt.Columns.Add(dc2);
        for (int i = 0; i < 10; i++)
        {
            DataRow dr = dt.NewRow();
            dr["UserID"] = 1;
            dr["UserName"] = "user" + i;
            dt.Rows.Add(dr);
        }
        HVDDataGrid1.DataSource = dt;
        HVDDataGrid1.DataBind();
    }
}

Answer 6

呵呵呵，谢谢了，但是，在使用该控件时，加上 this.HVDDataGrid1.AutoGenerateColumns = false;数据还是出不来了。