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ADO.net实体回传的GridView数据源

2012-09-01 46 views
1

我试图绑定一个ADO实体查询到GridView，但每个事件的gridview的火灾导致页面回发。每次回发页面，数据源都为空，我必须再次绑定查询。ADO.net实体回传的GridView数据源

所有的代码作品找到用于显示和编辑数据，除了RowUpdating事件。

我的问题在于，当RowUpdating事件触发时，页面不回发，我必须再一次结合松动，我想更新数据库中选择值的数据。如果我不再次绑定数据，数据源为空，我的.findcontrol返回一个ArgumentOutOfRange异常。

我通过测试代码的其余部分在RowUpdating事件：

1）上RowUpdating事件

2中设置断点）点击改变数据在更新超链接

3）使用SQL Server Management Studio中

4）继续执行代码

5）重新执行查询中SQ表大号短信

在此之后在表中的数据进行了更新，旧值

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using HCA_QualityModel; 


public partial class Admin : System.Web.UI.Page 
{ 
    static HCA_QualityEntities database = new HCA_QualityEntities(); 
    static object grvMachinesQuery = (from m in database.Machines 
             from d in database.Workcenters 
             where m.WorkcenterFK == d.id 
             select 
              new { id = m.id, MachineName = m.MachineName, WorkCenterFK = d.WorkCenterName }); 
    protected void Page_Load(object sender, EventArgs e) 
    { 
     //bind the gridview on intial page load 
     if (!Page.IsPostBack) bindGridViewData(); 
    } 
    protected void bindGridViewData() 
    { 
     //Data binds for gridviews and ddl's 

     grvMachines.DataSource = grvMachinesQuery; 
     grvWorkCenters.DataSource = (from w in database.Workcenters select w); 
     grvUsers.DataSource = (from u in database.Users select u); 
     ddlAddDept.DataSource = grvWorkCenters.DataSource; 
     ddlAddDept.DataValueField = "id"; 
     ddlAddDept.DataTextField = "WorkCenterName"; 
     DataBind(); 
    } 
    //Adds new data to the db, then rebinds the griviews to the db 
    #region Submit Buttons 
    protected void btnSubmitMachine_Click(object sender, EventArgs e) 
    { 
     //add new machine to the database 

     Machine temp = new Machine(); 
     temp.MachineName = txtAddMachine.Text; 
     temp.WorkcenterFK = Int32.Parse(ddlAddDept.SelectedValue); 
     database.Machines.AddObject(temp); 
     database.SaveChanges(); 
     bindGridViewData(); 

    } 
    protected void btnSubmitDept_Click(object sender, EventArgs e) 
    { 
     //add new workcenter to database 

     Workcenter temp = new Workcenter(); 
     temp.WorkCenterName = txtAddDept.Text; 
     database.Workcenters.AddObject(temp); 
     database.SaveChanges(); 
     bindGridViewData(); 
    } 
    protected void btnUserSubmit_Click(object sender, EventArgs e) 
    { 
     //add new user to the database 

     HCA_QualityModel.User temp = new User(); 
     temp.Username = txtAddUser.Text; 
     temp.Password = txtAddPassword.Text; 
     database.Users.AddObject(temp); 
     database.SaveChanges(); 
     bindGridViewData(); 
    } 
    #endregion 
    //Handles Updating, editing, and deleting Gridview Controls 
    #region Gridview machines 
    protected void grvMachines_RowDataBound(object sender, GridViewRowEventArgs e) 
    { 

     DropDownList temp = (DropDownList)(e.Row.FindControl("ddlDept")); 
     if (temp != null) 
     { 
      temp.DataSource = (from w in database.Workcenters select w); 
      temp.DataTextField = "WorkCenterName"; 
      temp.DataValueField = "id"; 
      temp.DataBind(); 
     } 

    } 
    protected void grvMachines_RowDeleting(object sender, GridViewDeleteEventArgs e) 
    { 

     int id = Int32.Parse(((Label)grvMachines.Rows[e.RowIndex].FindControl("lblId") as Label).Text); 
     database.Machines.DeleteObject(((Machine)(from m in database.Machines where m.id == id select m).Single())); 
     database.SaveChanges(); 
     bindGridViewData(); 
    } 
    protected void grvMachines_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
    { 

     grvMachines.EditIndex = -1; 
     bindGridViewData(); 
    } 
    protected void grvMachines_RowEditing(object sender, GridViewEditEventArgs e) 
    { 
     grvMachines.EditIndex = e.NewEditIndex; 
     bindGridViewData(); 
    } 
    protected void grvMachines_RowUpdating(object sender, GridViewUpdateEventArgs e) 
    { 


     //Gridviews have no data on postback from events, rebinding looses the selected values from edit mode. 

     bindGridViewData(); 

     DropDownList dept = (DropDownList)grvMachines.Rows[grvMachines.EditIndex].FindControl("ddlDept"); 
     TextBox name = (TextBox)grvMachines.Rows[grvMachines.EditIndex].FindControl("txtMachine"); 
     Int32 id = (Convert.ToInt32(((Label)grvMachines.Rows[grvMachines.EditIndex].FindControl("lblId")).Text)); 

     //Working Code to update the database, recieving incorrect data from controls due to rebinding 
     HCA_QualityEntities database = new HCA_QualityEntities(); 
     Machine temp = (from m in database.Machines where m.id == id select m).First(); 
     temp.MachineName = (name.Text); 
     temp.WorkcenterFK = Int32.Parse(dept.SelectedValue); 
     database.SaveChanges(); 
     grvMachines.EditIndex = -1; 
     bindGridViewData(); 
    } 
    #endregion 
}

asp代码

<%@ Page Title="" Language="C#" MasterPageFile="~/site.master" AutoEventWireup="true" 
    CodeFile="Admin.aspx.cs" Inherits="Admin" %> 

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server"> 
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server"> 
     <table style="width:800px; vertical-align:top;"> 
     <tr style="width:800px;"> 
      <td style="width:230px; height:90px;"> 
       Add New Machine: 
       <br /> 
       &nbsp;Machine&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Dept 
       <br /> 
       <asp:TextBox ID="txtAddMachine" runat="server" Width="70px"></asp:TextBox> 
       <asp:DropDownList ID="ddlAddDept" runat="server" Width="110px"> 
       </asp:DropDownList> 
       <br /> 
       <asp:Button ID="btnSubmitMachine" runat="server" Text="Submit" 
       onclick="btnSubmitMachine_Click" /> 
      </td> 
      <td style="width:190px; height:90px;"> 
       Add New Dept: 
       <br /> 
       Dept Name 
       <br /> 
       <asp:TextBox ID="txtAddDept" runat="server" Width="100px"></asp:TextBox> 
       <br /> 
       <asp:Button ID="btnSubmitDept" runat="server" Text="Submit" 
       onclick="btnSubmitDept_Click" /> 
      </td> 
      <td style="width:250px; height:90px;"> 
       Add New User: 
       <br /> 
       &nbsp;Username&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Password 
       <br /> 
       <asp:TextBox ID="txtAddUser" runat="server" Width="90px"></asp:TextBox> 
       <asp:TextBox ID="txtAddPassword" runat="server" Width="90px"></asp:TextBox> 
       <br /> 
       <asp:Button ID="btnUserSubmit" runat="server" Text="Submit" 
       onclick="btnUserSubmit_Click" /> 
      </td> 
     </tr> 
     <tr style="width:800px; vertical-align:top;"> 
      <td style="width:230px;"> 
       <asp:GridView ID="grvMachines" runat="server" AutoGenerateColumns="False" 
        Width="230px" onrowdeleting="grvMachines_RowDeleting" 
        onrowediting="grvMachines_RowEditing" 
        onrowcancelingedit="grvMachines_RowCancelingEdit" 
        onrowupdating="grvMachines_RowUpdating" 
        onrowdatabound="grvMachines_RowDataBound" 
        EnableViewState="False"> 
        <Columns> 
         <asp:TemplateField Visible="false"> 
          <ItemTemplate> 
           <asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label> 
          </ItemTemplate> 
          <EditItemTemplate> 
           <asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label> 
          </EditItemTemplate> 
         </asp:TemplateField> 
         <asp:TemplateField HeaderText="Machine"> 
          <ItemTemplate> 
           <asp:Label ID="lblMachine" runat="server" Text='<%# Eval("MachineName") %>'></asp:Label> 
          </ItemTemplate> 
          <EditItemTemplate> 
           <asp:TextBox ID="txtMachine" runat="server" Text='<%# Eval("MachineName") %>'></asp:TextBox> 
          </EditItemTemplate> 
          <ControlStyle Width="50px" /> 
         </asp:TemplateField> 
         <asp:TemplateField HeaderText="Dept"> 
          <ItemTemplate> 
           <asp:Label ID="lblDept" runat="server" Text='<%# Eval("WorkcenterFK") %>'></asp:Label> 
          </ItemTemplate> 
          <EditItemTemplate> 
           <asp:DropDownList ID="ddldept" runat="server"> 
           </asp:DropDownList> 
          </EditItemTemplate> 
          <ControlStyle Width="120px" /> 
         </asp:TemplateField> 
         <asp:CommandField HeaderText="Actions" ShowEditButton="true" ShowDeleteButton="True" 
          ControlStyle-Width="50px" CausesValidation="False" > 
         </asp:CommandField> 
        </Columns> 
       </asp:GridView> 
      </td> 
      <td style="width:170px;"> 
       <asp:GridView ID="grvWorkCenters" runat="server" AutoGenerateColumns="False" 
        Width="170px"> 
        <Columns> 
         <asp:TemplateField HeaderText="id" Visible="false"> 
          <ItemTemplate> 
           <asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label> 
          </ItemTemplate> 
          <EditItemTemplate> 
           <asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label> 
          </EditItemTemplate> 
         </asp:TemplateField> 
         <asp:TemplateField HeaderText="WorkCenter"> 
          <ItemTemplate> 
           <asp:Label ID="lblWorkcenter" runat="server" Text='<%# Eval("WorkCenterName") %>'></asp:Label> 
          </ItemTemplate> 
          <EditItemTemplate> 
           <asp:TextBox ID="txtWorkcenter" runat="server" Text='<%# Eval("WorkCenterName") %>'></asp:TextBox> 
          </EditItemTemplate> 
          <ControlStyle Width="75px" /> 
         </asp:TemplateField> 
         <asp:CommandField HeaderText="Actions" ShowEditButton="true" ShowDeleteButton="true" 
          ControlStyle-Width="50px" CausesValidation="False" /> 
        </Columns> 
       </asp:GridView> 
      </td> 
      <td style="width:290px;"> 
       <asp:GridView ID="grvUsers" runat="server" AutoGenerateColumns="False" 
        Width="290px"> 
       <Columns> 
        <asp:TemplateField HeaderText="id" Visible="false"> 
         <ItemTemplate> 
          <asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label> 
         </ItemTemplate> 
         <EditItemTemplate> 
          <asp:TextBox ID="txtId" runat="server" Text='<%# Eval("id") %>'></asp:TextBox> 
         </EditItemTemplate> 
        </asp:TemplateField> 
        <asp:TemplateField HeaderText="User"> 
         <ItemTemplate> 
          <asp:Label ID="lblUser" runat="server" Text='<%# Eval("Username") %>'></asp:Label> 
         </ItemTemplate> 
         <EditItemTemplate> 
          <asp:TextBox ID="txtUser" runat="server" Text='<%# Eval("Username") %>'></asp:TextBox> 
         </EditItemTemplate> 
         <ControlStyle Width="120px" /> 
        </asp:TemplateField> 
        <asp:TemplateField HeaderText="Password"> 
         <ItemTemplate> 
          <asp:Label ID="lblPassword" runat="server" Text='<%# Eval("Password") %>'></asp:Label> 
         </ItemTemplate> 
         <EditItemTemplate> 
          <asp:TextBox ID="txtPassword" runat="server" Text='<%# Eval("Password") %>'></asp:TextBox> 
         </EditItemTemplate> 
         <ControlStyle Width="120px" /> 
        </asp:TemplateField> 
        <asp:CommandField HeaderText="Actions" ShowEditButton="true" ShowDeleteButton="true" 
         ControlStyle-Width="50px" CausesValidation="false" /> 
       </Columns> 
      </asp:GridView> 
      </td> 
     </tr> 
     </table> 

</asp:Content>

来源

2012-09-01 Kevin Howe

回答

1

我已经重构你的源代码，现在它应该工作。

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using HCA_QualityModel; 


public partial class Admin : System.Web.UI.Page 
{ 
static HCA_QualityEntities database = new HCA_QualityEntities(); 
    protected void Page_Load(object sender, EventArgs e) 
{ 
    //bind the gridview on intial page load 
    if (!Page.IsPostBack) bindGridViewData(); 
} 
protected void bindGridViewData() 
{ 

static object grvMachinesQuery = (from m in database.Machines 
            from d in database.Workcenters 
            where m.WorkcenterFK == d.id 
            select 
             new { id = m.id, MachineName = m.MachineName, WorkCenterFK = d.WorkCenterName }); 

    //Data binds for gridviews and ddl's 

    grvMachines.DataSource = grvMachinesQuery; 
    grvWorkCenters.DataSource = (from w in database.Workcenters select w); 
    grvUsers.DataSource = (from u in database.Users select u); 
    ddlAddDept.DataSource = grvWorkCenters.DataSource; 
    ddlAddDept.DataValueField = "id"; 
    ddlAddDept.DataTextField = "WorkCenterName"; 
    DataBind(); 
} 

//Adds new data to the db, then rebinds the griviews to the db 
#region Submit Buttons 
protected void btnSubmitMachine_Click(object sender, EventArgs e) 
{ 
    //add new machine to the database 

    Machine temp = new Machine(); 
    temp.MachineName = txtAddMachine.Text; 
    temp.WorkcenterFK = Int32.Parse(ddlAddDept.SelectedValue); 
    database.Machines.AddObject(temp); 
    database.SaveChanges(); 
    bindGridViewData(); 

} 
protected void btnSubmitDept_Click(object sender, EventArgs e) 
{ 
    //add new workcenter to database 

    Workcenter temp = new Workcenter(); 
    temp.WorkCenterName = txtAddDept.Text; 
    database.Workcenters.AddObject(temp); 
    database.SaveChanges(); 
    bindGridViewData(); 
} 
protected void btnUserSubmit_Click(object sender, EventArgs e) 
{ 
    //add new user to the database 

    HCA_QualityModel.User temp = new User(); 
    temp.Username = txtAddUser.Text; 
    temp.Password = txtAddPassword.Text; 
    database.Users.AddObject(temp); 
    database.SaveChanges(); 
    bindGridViewData(); 
} 
#endregion 
//Handles Updating, editing, and deleting Gridview Controls 
#region Gridview machines 
protected void grvMachines_RowDataBound(object sender, GridViewRowEventArgs e) 
{ 

    DropDownList temp = (DropDownList)(e.Row.FindControl("ddlDept")); 
    if (temp != null) 
    { 
     temp.DataSource = (from w in database.Workcenters select w); 
     temp.DataTextField = "WorkCenterName"; 
     temp.DataValueField = "id"; 
     temp.DataBind(); 
    } 

} 
protected void grvMachines_RowDeleting(object sender, GridViewDeleteEventArgs e) 
{ 

    int id = Int32.Parse(((Label)grvMachines.Rows[e.RowIndex].FindControl("lblId") as Label).Text); 
    database.Machines.DeleteObject(((Machine)(from m in database.Machines where m.id == id select m).Single())); 
    database.SaveChanges(); 
    bindGridViewData(); 
} 
protected void grvMachines_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
{ 

    grvMachines.EditIndex = -1; 
    bindGridViewData(); 
} 
protected void grvMachines_RowEditing(object sender, GridViewEditEventArgs e) 
{ 
    grvMachines.EditIndex = e.NewEditIndex; 
    bindGridViewData(); 
} 
protected void grvMachines_RowUpdating(object sender, GridViewUpdateEventArgs e) 
{ 


    //Gridviews have no data on postback from events, rebinding looses the selected values from edit mode. 

    bindGridViewData(); 

    DropDownList dept = (DropDownList)grvMachines.Rows[grvMachines.EditIndex].FindControl("ddlDept"); 
    TextBox name = (TextBox)grvMachines.Rows[grvMachines.EditIndex].FindControl("txtMachine"); 
    Int32 id = (Convert.ToInt32(((Label)grvMachines.Rows[grvMachines.EditIndex].FindControl("lblId")).Text)); 

    //Working Code to update the database, recieving incorrect data from controls due to rebinding 
    HCA_QualityEntities database = new HCA_QualityEntities(); 
    Machine temp = (from m in database.Machines where m.id == id select m).First(); 
    temp.MachineName = (name.Text); 
    temp.WorkcenterFK = Int32.Parse(dept.SelectedValue); 
    database.SaveChanges(); 
    grvMachines.EditIndex = -1; 
    bindGridViewData(); 
} 
#endregion

}

来源

2012-09-02 00:41:33

+0

谢谢你的回复，但恐怕重构并没有帮助。 我stll必须调用bindgridviewdata（）在RowUpdating事件，然后与不是那些用户在编辑模式下改变了旧的价值观念更新数据库的开始。如果我在rowupdating事件的开始时没有调用bindgridviewdata（），我会继续使用argumentofrange异常。 –

1

你能暂时断开事件处理程序？

myGridView.rowUpdating -= myGridView_rowUpdating; 
//code to populate 
myGridView.rowUpdating += myGridView_rowupdating;

或者C# Disable Event Handler Problem

我有一个靠不住的验证模块，我试图重构为在我的数据绑定被刷新的时候我没有他们想要一份工作，使他们重新绑定，然后再重新绑定我结束了这个递归的y汤。我只有一个实例，所以我只是将事件处理程序关闭并重新打开。

来源

2012-09-02 13:47:27 Bmo

+0

不知道往哪里放这个， 的问题是不是在GridView随机刷新我的databinds，我手动刷新他们，因为没有数据源访问RowUpdating事件触发时。 –

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