用模板列VB.net

Question

我嘗試更新，但我得到一個錯誤的DataGrid更新「的索引超出limits.I不應該是負值，應該比集合的大小更小的」這種擔心這條線在調試「暗淡courseId作爲字符串= gridViewCourse.DataKeys（e.RowIndex）.Values（ 「CourseId」）。的ToString（）」

這是我的網格ASP代碼

<asp:GridView ID="gridViewCourse" 
    runat="server" 
    AutoGenerateColumns="False" 
    onrowcancelingedit="gridViewCourse_RowCancelingEdit" 
    onrowdeleting="gridViewCourse_RowDeleting" onrowediting="gridViewCourse_RowEditing" 
    onrowupdating="gridViewCourse_RowUpdating" 
    onrowcommand="gridViewCourse_RowCommand"   
    ShowFooter="True"> 


    <Columns> 
    <asp:TemplateField> 
    <EditItemTemplate> 
    <asp:ImageButton ID="imgbtnUpdate" CommandName="Update" runat="server" ImageUrl="~/Images/update.jpg" ToolTip="Update" Height="20px" Width="20px" /> 
    <asp:ImageButton ID="imgbtnCancel" runat="server" CommandName="Cancel" ImageUrl="~/Images/Cancel.jpg" ToolTip="Cancel" Height="20px" Width="20px" /> 
    </EditItemTemplate> 
    <ItemTemplate> 
     <asp:ImageButton ID="imgbtnEdit" CommandName="Edit" runat="server" ImageUrl="~/Images/Edit.jpg" ToolTip="Edit" Height="20px" Width="20px" /> 
     <asp:ImageButton ID="imgbtnDelete" CommandName="Delete" Text="Edit" runat="server" ImageUrl="~/Images/delete.jpg" ToolTip="Delete" Height="20px" Width="20px" /> 
     </ItemTemplate> 
     <FooterTemplate> 
     <asp:ImageButton ID="imgbtnAdd" runat="server" ImageUrl="~/Images/AddNewitem.jpg" CommandName="AddNew" Width="30px" Height="30px" ToolTip="Add new User" ValidationGroup="validaiton" /> 
    </FooterTemplate> 
    </asp:TemplateField> 

    <asp:TemplateField HeaderText="Id Cours"> 
    <EditItemTemplate> 
    <asp:Label ID="lbleditId" runat="server" Text='<%#Eval("CourseId") %>'/> 
    </EditItemTemplate> 
     <ItemTemplate> 
     <asp:Label ID="lblitemId" runat="server" Text='<%#Eval("CourseId") %>'/> 
     </ItemTemplate> 
     <FooterTemplate> 
      <asp:TextBox ID="txtftrId" runat="server"/> 
      <asp:RequiredFieldValidator ID="rfvId" runat="server" ControlToValidate="txtftrId" Text="*" ValidationGroup="validaiton"/> 
        </FooterTemplate> 
       </asp:TemplateField> 


       <asp:TemplateField HeaderText="Cours"> 
        <EditItemTemplate> 
          <asp:TextBox ID="txtCours" runat="server" Text='<%#Eval("CourseName") %>'/> 
        </EditItemTemplate> 
        <ItemTemplate> 
         <asp:Label ID="lblCours" runat="server" Text='<%#Eval("CourseName") %>'/> 
        </ItemTemplate> 
        <FooterTemplate> 
         <asp:TextBox ID="txtftrCours" runat="server"/> 
        <asp:RequiredFieldValidator ID="rfvCours" runat="server" ControlToValidate="txtftrCours" Text="*" ValidationGroup="validaiton"/> 
        </FooterTemplate> 
       </asp:TemplateField> 


       <asp:TemplateField HeaderText="Prix"> 
        <EditItemTemplate> 
         <asp:TextBox ID="txtPrix" runat="server" Text='<%#Eval("Price") %>'/> 
        </EditItemTemplate> 
        <ItemTemplate> 
         <asp:Label ID="lblPrix" runat="server" Text='<%#Eval("Price") %>'/> 
        </ItemTemplate> 
        <FooterTemplate> 
         <asp:TextBox ID="txtftrPrix" runat="server"/> 
        <asp:RequiredFieldValidator ID="rfvPrix" runat="server" ControlToValidate="txtftrPrix" Text="*" ValidationGroup="validaiton"/> 
        </FooterTemplate> 
       </asp:TemplateField> 

       <asp:TemplateField HeaderText="Tuteur"> 
        <EditItemTemplate> 
         <asp:TextBox ID="txtTuteur" runat="server" Text='<%#Eval("Tutor") %>'/> 
        </EditItemTemplate> 
        <ItemTemplate> 
         <asp:Label ID="lblTuteur" runat="server" Text='<%#Eval("Tutor") %>'/> 
        </ItemTemplate> 
        <FooterTemplate> 
         <asp:TextBox ID="txtftrTuteur" runat="server"/> 
        <asp:RequiredFieldValidator ID="rfvTuteur" runat="server" ControlToValidate="txtftrTuteur" Text="*" ValidationGroup="validaiton"/> 
        </FooterTemplate> 
       </asp:TemplateField> 
     </Columns> 
    </asp:GridView> 

這是我的方法來更新

 Protected Sub gridViewCourse_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs) 

    Dim courseId As String = gridViewCourse.DataKeys(e.RowIndex).Values("CourseId").ToString() 
    Dim courseName As TextBox = DirectCast(gridViewCourse.Rows(e.RowIndex).FindControl("CourseName"), TextBox) 
    Dim price As TextBox = DirectCast(gridViewCourse.Rows(e.RowIndex).FindControl("Price"), TextBox) 
    Dim tutor As TextBox = DirectCast(gridViewCourse.Rows(e.RowIndex).FindControl("Tutor"), TextBox) 
    con.Open() 
    Dim cmd As New SqlCommand(("update Courses set CourseName='" + courseName.Text & "',Price='" + price.Text & "',Tutor='") + tutor.Text & "' where CourseID=" & courseid, con) 
    cmd.ExecuteNonQuery() 
    con.Close() 
    lblresult.ForeColor = Color.Green 
    lblresult.Text = " Details Updated successfully" 
    gridViewCourse.EditIndex = -1 
    BindCoursesDetails() 
End Sub 

所以這條線將造成T他的錯誤，我上面

 Dim courseId As String = gridViewCourse.DataKeys(e.RowIndex).Values("CourseId").ToString() 

提到這條線是假設得到CourseId的價值以後用它來更新

感謝弗蘭克

Answer 1

您需要設置DataKeyNamesGridView控制的屬性。

<asp:GridView ID="gridViewCourse" 
    runat="server" 
    AutoGenerateColumns="False" 
    onrowcancelingedit="gridViewCourse_RowCancelingEdit" 
    onrowdeleting="gridViewCourse_RowDeleting" onrowediting="gridViewCourse_RowEditing" 
    onrowupdating="gridViewCourse_RowUpdating" 
    onrowcommand="gridViewCourse_RowCommand" 
    datakeynames="CourseId" 
    ShowFooter="True"> 

編輯：（從評論）

你的更新語句是無效的。

Dim sql="UPDATE Courses set CourseName=@CourseName,Price=@Price,Tutor=@Tutor Where CourseID=@CourseID" 

cmd=New SqlCommand(sql,con) 
cmd.Parameters.Add("@CourseName",SqlDbType.VarChar,30).Value=courseName.Text 
cmd.Parameters.Add("@Price",SqlDbType.VarChar,20).Value=price.Text 
cmd.Parameters.Add("@Tutor",SqlDbType.VarChar,30).Value=tutor.Text 
cmd.Parameters.Add("@CourseID",SqlDbType.VarChar,10).Value=courseid 

con.Open() 
cmd.ExecuteNonQuery() 
cn.Close();