ASP.NET(1):GridView动态绑定控件的处理方式。

1.在Gridview_RowDataBound中根据条件创建控件。

2.测试时发现在回发的时候动态创建的控件没有了。

解决：在回发的时候再动态创建控件

    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
            CreateGridControl();
    }

3.使用过程中发现，绑定二次绑定数据源时，控件没值了

原因：Gridview_RowDataBound绑定时，给控件的赋值都进行了IsPostBack的判断.所以没值

解决：提供绑定时的属性支持

    bool ReRowDataBoundFlag
    {
        get
        {
            if (ViewState["RowDataBoundFlag"] == null)
            {
                ViewState["RowDataBoundFlag"] = true;
            }
            return (bool)ViewState["RowDataBoundFlag"];
        }
        set
        {
            ViewState["RowDataBoundFlag"] = value;
        }
    }

总结：

1.动态绑定的控件的值已经被写入了ViewState了，只要在回发的时候创建控件，就可以正常处理了。

2.动态绑定的控件如果有数据源（例如：DrowDownList），那么数据源需要重新绑定。

3.也许ReRowDataBoundFlag属性可以不要，原因时在DataBind中进行的IsPostBack的判断也许是多余的。（没有经过测试）

4.如果不用的行要根据不同的值创建不同的对象，最好将值用过HiddenField进行保存，这样在创建控件的时候就可以有判断的依据

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections.Generic;
using BLL.PersonnelAction;
using BLL.Sys;
using BLL.RightCenter;
using BLL.EmployeeNS;
using BLL.Model;
using BLL.PersonnelAction.PersonnelActionbusinessClass;

public partial class UC : System.Web.UI.UserControl
{

    public List<PersonnelActionItemBindEntity> GetEntities()
    {
        List<PersonnelActionItemBindEntity> list = new List<PersonnelActionItemBindEntity>();
        foreach (GridViewRow row in gvActionTerm.Rows)
        {
            var hd = (HiddenField)row.FindControl("hfActionItemId");
            int? actionItemId = hd.Value.Trim().Length == 0 ? null : (int?)int.Parse(hd.Value);

            hd = (HiddenField)row.FindControl("hfActionTermId");
            int actionTermId = int.Parse(hd.Value);

            string oldData = ((HiddenField)row.FindControl("hdOldData")).Value;

            DropDownList ddl = row.FindControl("ddlReasonId") as DropDownList;
            int? reasonId = ddl.SelectedValue == Utility.DllShowDefaultValue ? null : (int?)int.Parse(ddl.SelectedValue);

            string newData = null;

            var tb = row.FindControl("tbNewData") as TextBox;
            if (tb != null)
            {
                newData = tb.Text;
            }

            ddl = row.FindControl("ddl_position") as DropDownList;
            if (ddl != null)
            {
                newData = ddl.SelectedValue;
            }

            ddl = row.FindControl("ddlNewData") as DropDownList;
            if (ddl != null)
            {
                newData = ddl.SelectedValue;
            }

            list.Add(new PersonnelActionItemBindEntity(actionTermId, actionItemId, oldData, newData, reasonId));
        }
        return list;
    }

    public void BindEntities(List<PersonnelActionItemBindEntity> list)
    {
        ReRowDataBoundFlag = true;
        gvActionTerm.DataSource = list;
        gvActionTerm.DataBind();
    }

    bool ReRowDataBoundFlag
    {
        get
        {
            if (ViewState["RowDataBoundFlag"] == null)
            {
                ViewState["RowDataBoundFlag"] = true;
            }
            return (bool)ViewState["RowDataBoundFlag"];
        }
        set
        {
            ViewState["RowDataBoundFlag"] = value;
        }
    }

    gvActionTerm_RowDataBound#region gvActionTerm_RowDataBound

    protected void gvActionTerm_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        //创建建各种控件，以及绑定信息
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            var entity = e.Row.DataItem as PersonnelActionItemBindEntity;

            //属性名称
            string temp_PropertyName;
            string temp_TermName;

            if (IsPostBack && !ReRowDataBoundFlag)
            {
                temp_PropertyName = ((HiddenField)e.Row.FindControl("hfPropertyName")).Value;
                temp_TermName = ((Label)e.Row.FindControl("lbTermName")).Text;
            }
            else
            {

                var temp_pat = PAT.GetPersonnerActionTerm(entity.ActionTermId);

                temp_PropertyName = temp_pat.PropertyName;
                temp_TermName = temp_pat.Name;
            }

            if (!IsPostBack || ReRowDataBoundFlag)
            {
                //One Column

                ((HiddenField)e.Row.FindControl("hfActionItemId")).Value = (entity.ActionItemId == null ? "" : entity.ActionItemId.ToString());
                ((HiddenField)e.Row.FindControl("hfActionTermId")).Value = entity.ActionTermId.ToString();
                ((HiddenField)e.Row.FindControl("hfPropertyName")).Value = temp_PropertyName;
                ((Label)e.Row.FindControl("lbTermName")).Text = temp_TermName;


                //Two Column
                string str_two = "";
                switch (temp_PropertyName)
                {
                    case PersonnelActionItemConst.PersonnelActionSalary: 
                        str_two = entity.OldData;
                        break;
                    case PersonnelActionItemConst.PersonnelActionGrade:
                    case PersonnelActionItemConst.PersonnelActionPosition:
                    case PersonnelActionItemConst.PersonnelActionSalaryGrade:
                    case PersonnelActionItemConst.PersonnelActionCategory:
                        str_two = PersonnelActionBLL.GetNameByNo(temp_PropertyName, entity.OldData);
                       
                        break;
                    default:
                        break;
                }
                ((HiddenField)e.Row.FindControl("hdOldData")).Value = entity.OldData;

                ((Label)e.Row.FindControl("lbOldData")).Text = str_two;
            }

            //Threee Column

            switch (temp_PropertyName)
            {
                case PersonnelActionItemConst.PersonnelActionSalary:
                    var tb = new TextBox();
                    tb.ID = "tbNewData";
                    tb.CssClass = "ShortText";
                    if (!IsPostBack || ReRowDataBoundFlag)
                        tb.Text = entity.NewData;
                    e.Row.Cells[2].Controls.Add(tb);
                    break;
                case PersonnelActionItemConst.PersonnelActionPosition:
                    DropDownList ddl_position = new DropDownList();
                    ddl_position.ID = "ddl_position";
                    if (!IsPostBack || ReRowDataBoundFlag)
                    {
                        PersonnelActionBLL.BindDropDownListByType(ddl_position, temp_PropertyName, entity.NewData, GetPageLoginInfo());
                        ddl_position.SelectedValue = entity.NewData;
                    }
                    DropDownList ddl_depart = new DropDownList();
                    ddl_depart.ID = "ddl_depart";
                    if (!IsPostBack || ReRowDataBoundFlag)
                    {
                        Utility.InitDDLDepartment(ddl_depart, GetPageLoginInfo());
                        if (!string.IsNullOrEmpty(entity.NewData))
                        {
                            var departobj = (new Position()).GetPositionInfo(Convert.ToInt32(entity.NewData));
                            if (departobj != null)
                            {
                                int departid = departobj.DepartmentID;
                                ddl_depart.SelectedValue = departid.ToString();
                            }
                        }
                    }
                    ddl_depart.Width = 100;
                    ddl_position.Width = 100;
                    ddl_depart.AutoPostBack = true;
                    ddl_depart.SelectedIndexChanged += new EventHandler(ddl_depart_SelectedIndexChanged);
                    e.Row.Cells[2].Controls.Add(ddl_depart);
                    e.Row.Cells[2].Controls.AddAt(1, ddl_position);
                    break;
                case PersonnelActionItemConst.PersonnelActionGrade:
                case PersonnelActionItemConst.PersonnelActionSalaryGrade:
                case PersonnelActionItemConst.PersonnelActionCategory:
                    DropDownList ddl = new DropDownList();
                    ddl.ID = "ddlNewData";
                    if (!IsPostBack || ReRowDataBoundFlag)
                    {
                        PersonnelActionBLL.BindDropDownListByType(ddl, temp_PropertyName, entity.NewData, GetPageLoginInfo());
                        ddl.SelectedValue = entity.NewData;
                    }
                    e.Row.Cells[2].Controls.Add(ddl);
                    break;
                default:
                    break;
            }

            //Four Column 
            DropDownList actionReason = e.Row.FindControl("ddlReasonId") as DropDownList;
            if (!IsPostBack || ReRowDataBoundFlag)
            {
                Utility.InitActionReason(actionReason, entity.ActionTermId);
                actionReason.SelectedValue = entity.ReasonId.HasValue ? entity.ReasonId.ToString() : "";
            }
        }
    }

    #endregion

    ddl_depart_SelectedIndexChanged#region ddl_depart_SelectedIndexChanged

    void ddl_depart_SelectedIndexChanged(object sender, EventArgs e)
    {
        
        var ddl_depart = (DropDownList)sender;
        int departmentId = int.Parse(ddl_depart.SelectedValue);
        var ddl_position = ddl_depart.Parent.Parent.FindControl("ddl_position") as DropDownList;
        Utility.InitPosition(departmentId, ddl_position);
    }

    #endregion

    PersonnelActionTerm pAT;

  
    PersonnelActionTerm PAT
    {
        get
        {
            if (pAT == null)
                pAT = new PersonnelActionTerm();
            return pAT;
        }
    }

    
    public LoginInfo GetPageLoginInfo()
    {
        return ((BasePage)this.Page).loginInfo;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
            CreateGridControl();
    }

    CreateGridControl#region CreateGridControl

    /**//// <summary>
    /// 回发时创建Grid变动列控件
    /// </summary>
    void CreateGridControl()
    {
        //创建建各种控件，以及绑定信息
        foreach (GridViewRow row in gvActionTerm.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                //属性名称
                string temp_PropertyName;
                string temp_TermName;

                temp_PropertyName = ((HiddenField)row.FindControl("hfPropertyName")).Value;
                temp_TermName = ((Label)row.FindControl("lbTermName")).Text;

                //Threee Column

                switch (temp_PropertyName)
                {
                    case PersonnelActionItemConst.PersonnelActionSalary:
                        var tb = new TextBox();
                        tb.ID = "tbNewData";
                        tb.CssClass = "ShortText";
                        row.Cells[2].Controls.Add(tb);
                        break;
                   
                    case PersonnelActionItemConst.PersonnelActionPosition:
                        DropDownList ddl_position = new DropDownList();
                        ddl_position.ID = "ddl_position";
                        DropDownList ddl_depart = new DropDownList();
                        ddl_depart.ID = "ddl_depart";

                        ddl_depart.Width = 100;
                        ddl_position.Width = 100;
                        ddl_depart.AutoPostBack = true;
                        Utility.InitDDLDepartment(ddl_depart, GetPageLoginInfo());
                        ddl_depart.SelectedIndexChanged += new EventHandler(ddl_depart_SelectedIndexChanged);
                        row.Cells[2].Controls.Add(ddl_depart);
                        row.Cells[2].Controls.AddAt(1, ddl_position);

                       
                        break;
                    case PersonnelActionItemConst.PersonnelActionGrade:
                    case PersonnelActionItemConst.PersonnelActionSalaryGrade:
                    case PersonnelActionItemConst.PersonnelActionCategory:
                        DropDownList ddl = new DropDownList();
                        ddl.ID = "ddlNewData";
                        PersonnelActionBLL.BindDropDownListByType(ddl, temp_PropertyName, "", GetPageLoginInfo());
                        row.Cells[2].Controls.Add(ddl);
                        break;
                    default:
                        break;
                }
            }
        }

    #endregion

    }

}