如何在主细节GridView和DetailsView中隐藏和显示DetailsView？

Question

我试图遵循并利用有关Quiz Engine的ASP.NET网站中的解释示例。 我在结果页面中有一个Master-Details，当用户在GridView中选择他所回答的问题之一时，该问题的详细信息将显示在GridView下方的DetailsView中。 一切正常。 我现在要隐藏的是DetailsView（这是已回答问题的详细信息），除非用户选择已回答问题之一。 那么该怎么做呢？

我将DetailsView的可见性设置为false，但是我不知道如何基于用户单击SELECT选项来隐藏/显示。

我的ASP.NET代码：

<tr>
                <td>
                    <asp:GridView ID="resultGrid" runat="server" DataKeyNames="QuestionID" SelectedIndex="0" 
                    AutoGenerateColumns="False" CellPadding="4" ForeColor="#333333" GridLines="None" AutoGenerateSelectButton="True" OnSelectedIndexChanged="resultGrid_SelectedIndexChanged" Width="555px">
                        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                        <RowStyle BackColor="#F7F6F3" ForeColor="#333333" CssClass="generaltext" HorizontalAlign="Center" />
                        <Columns>
                            <asp:BoundField DataField="QuestionID" HeaderText="Question" />
                            <%--<asp:BoundField DataField="CorrectAnswer" HeaderText="Correct Answer" />--%>
                            <asp:BoundField DataField="UserAnswer" HeaderText="Your Answer" />
                            <asp:BoundField DataField="Result" HeaderText="Result" />
                        </Columns>
                        <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                        <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                        <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" CssClass="boldtext" />
                        <EditRowStyle BackColor="#999999" />
                        <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                    </asp:GridView>

                    <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:testConnectionString %>"
                        SelectCommand="SELECT [Question], [Answer1], [Answer2], [Answer3], [QuestionID], [QuestionOrder], [Answer4], [CorrectAnswer], [AnswerExplanation], [QuizID] FROM [Question] WHERE ([QuizID] = @QuizID) ORDER BY [QuestionOrder]">
                        <SelectParameters>
                            <asp:SessionParameter Name="QuizID" SessionField="QuizID" Type="Int32" />
                        </SelectParameters>
                    </asp:SqlDataSource>                
                </td>
            </tr>
            <tr>
                <td>
                    <asp:DetailsView ID="answerDetails" runat="server" CellPadding="4" ForeColor="#333333"
                        GridLines="None" Height="45px" Width="552px" DataSourceID="SqlDataSource1" 
                        AutoGenerateRows="False" DataKeyNames="QuestionID" Visible="false">

                        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                        <CommandRowStyle BackColor="#E2DED6" Font-Bold="True" />
                        <RowStyle BackColor="#F7F6F3" ForeColor="#333333" CssClass="generaltext" />
                        <FieldHeaderStyle BackColor="#E9ECF1" Font-Bold="True" CssClass="boldtext" Width="100px" />
                        <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                        <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                        <EditRowStyle BackColor="#999999" />
                        <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                        <Fields>
                            <asp:BoundField DataField="Question" HeaderText="Question" 
                                SortExpression="Question" />
                            <asp:BoundField DataField="Answer1" HeaderText="A" 
                                SortExpression="Answer1" />
                            <asp:BoundField DataField="Answer2" HeaderText="B" 
                                SortExpression="Answer2" />
                            <asp:BoundField DataField="Answer3" HeaderText="C" 
                                SortExpression="Answer3" />
                            <asp:BoundField DataField="Answer4" HeaderText="D" 
                                SortExpression="Answer4" />
                            <asp:BoundField DataField="CorrectAnswer" HeaderText="Correct Answer" 
                                SortExpression="CorrectAnswer" HeaderStyle-BackColor="lightgreen" />
                            <asp:BoundField DataField="AnswerExplanation" HeaderText="Explanation" 
                                SortExpression="AnswerExplanation" HeaderStyle-BackColor="lightgreen" />
                        </Fields>
                    </asp:DetailsView>                
                </td>
            </tr>

后台代码：

public partial class Results : System.Web.UI.Page
{
    Object bShowDetailsView;
    protected void Page_Load(object sender, EventArgs e)
    {
       bShowDetailsView = false;

        ArrayList al = (ArrayList)Session["AnswerList"];

        if (al == null)
        {
            Response.Redirect("default.aspx");
        }

        resultGrid.DataSource = al;
        resultGrid.DataBind();

        // Save the results into the database.
        if (IsPostBack == false)
        {
            // Calculate score
            double questions = al.Count;
            double correct = 0.0;


            for (int i = 0; i < al.Count; i++)
            {
                Answer a = (Answer)al[i];
                if (a.Result == Answer.ResultValue.Correct)
                    correct++;
            }

            double score = (correct / questions) * 100;
            string username = HttpContext.Current.User.Identity.Name.ToString().Replace("ARAMCO\\", "");
            SqlDataSource userQuizDataSource = new SqlDataSource();
            userQuizDataSource.ConnectionString = ConfigurationManager.ConnectionStrings["testConnectionString"].ToString();
            userQuizDataSource.InsertCommand = "INSERT INTO [UserQuiz] ([QuizID], [DateTimeComplete], [Score], [Username]) VALUES (@QuizID, @DateTimeComplete, @Score, @Username)";

            userQuizDataSource.InsertParameters.Add("QuizID", Session["QuizID"].ToString());
            userQuizDataSource.InsertParameters.Add("DateTimeComplete", DateTime.Now.ToString());

            // "N4" is for displaying four decimal places, regardless of what the value is 
            userQuizDataSource.InsertParameters.Add("Score", score.ToString("N4"));

            userQuizDataSource.InsertParameters.Add("Username", username);

            int rowsAffected = userQuizDataSource.Insert();
            if (rowsAffected == 0)
            {
                // Let's just notify that the insertion didn't
                // work, but let' s continue on ...
                errorLabel.Text = "There was a problem saving your quiz results into our database.  Therefore, the results from this quiz will not be displayed on the list on the main menu.";
            }

        }


    }


    protected void resultGrid_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlDataSource1.FilterExpression = "QuestionOrder=" + resultGrid.SelectedValue;
        bShowDetailsView = true;
        answerDetails.Visible = bShowDetailsView;
    }



}

Answer 1

为什么不默认选择resultGrid中的第一条记录，因为您处理的事件是SelectedIndexChanged而不是Selected / Unselected（我不知道这些是否存在）