repeater控件，大侠们进来看看啊

Question

用repeater控件还原学生的答题，例如考试时学生选择的是B,然后从数据库中取学生答案，显示在repeater中，现在完成的代码如下：     <asp:Repeater ID="rpSingle" runat="server" >
    <HeaderTemplate><strong>一、单选题</strong></HeaderTemplate>
        <ItemTemplate>
            <ul>
                <li>
                    <%#(Container.ItemIndex+1)%>.&nbsp<asp:Label ID="lblSingleQ" runat="server" Text='<%#Eval("question") %>'></asp:Label>
                    <asp:Label
                        ID="lblQid" runat="server" Text='<%#Eval("question_id") %>' Visible="false"></asp:Label>
                </li>
                <li>
                    <asp:RadioButton ID="rbA" runat="server" GroupName="s1" Text='<%#Eval("a") %>' />
                </li>
                <li>
                    <asp:RadioButton ID="rbB" runat="server" GroupName="s1" Text='<%#Eval("b") %>' />
                    </li>
                <li>
                    <asp:RadioButton ID="rbC" runat="server" GroupName="s1" Text='<%#Eval("c") %>' />
                </li>
                <li>
                    <asp:RadioButton ID="rbD" runat="server" GroupName="s1" Text='<%#Eval("d") %>' />
                </li>
                <br />                <li>
                    <asp:Label ID="lblSingleStuPlay" runat="server" ForeColor="Blue" Text="学生答案是："></asp:Label><asp:Label ID="lblStuAnswer" ForeColor="Blue" runat="server" Text='<%#Eval("student_answer")%>'></asp:Label>
                   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <asp:Label ID="lblSinglePlay" runat="server" ForeColor="Blue" Text=" 正确答案是:" ></asp:Label> <asp:Label ID="lblAnswer" ForeColor="Blue" runat="server" Text='<%#Eval("answer") %>'></asp:Label>
                </li>
            </ul>
        </ItemTemplate>
    </asp:Repeater>实现图：
，就是radiobutton根据数据库的答案呈现选中状态求解答
也可以不用repeater实现

Answer 1

<asp:RadioButton ID="rbD" runat="server" GroupName="s1" Text='<%#Eval("d") %>' Selected=<%#questionanswer=d?"true":"false"#>/>

Answer 2

如果这种方法可行的话那岂不是在每一个选项绑定后边都得这样写？
你这个selected好像不行，测试没过

Answer 3

这是前台的用法，后台方法加入
 onitemdatabound="Repeater1_ItemDataBound" //事件代码    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        Label lb = (Label)e.Item.FindControl("lblAnswer");
        RadioButton rbSelected = null;
        switch (lb.Text.ToLower())
        {
            case "a":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "b":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "c":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            default:
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
        }
        rbSelected.Checked = true;
    }

Answer 4

这是前台的用法，后台方法加入
 onitemdatabound="Repeater1_ItemDataBound" //事件代码    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        Label lb = (Label)e.Item.FindControl("lblAnswer");
        RadioButton rbSelected = null;
        switch (lb.Text.ToLower())
        {
            case "a":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "b":
                rbSelected = (RadioButton)e.Item.FindControl("rbB");
                break;
            case "c":
                rbSelected = (RadioButton)e.Item.FindControl("rbC");
                break;
            default:
                rbSelected = (RadioButton)e.Item.FindControl("rbD");
                break;
        }
        rbSelected.Checked = true;
    }

注意

Answer 5

这是前台的用法，后台方法加入
 onitemdatabound="Repeater1_ItemDataBound" //事件代码    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        Label lb = (Label)e.Item.FindControl("lblAnswer");
        RadioButton rbSelected = null;
        switch (lb.Text.ToLower())
        {
            case "a":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "b":
                rbSelected = (RadioButton)e.Item.FindControl("rbB");
                break;
            case "c":
                rbSelected = (RadioButton)e.Item.FindControl("rbC");
                break;
            default:
                rbSelected = (RadioButton)e.Item.FindControl("rbD");
                break;
        }
        rbSelected.Checked = true;
    }

注意
注意什么？？？如果我的题是多选题呢？后台怎么办？不能把所有情况都列出来吧？用前台那个方法？可是不会用啊，求赐教

Answer 6

注意这个，
多选题就把单选框换多选框，
    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        //获取标准答案 例如多选 a,b,c  或 a,b
        Label lb = (Label)e.Item.FindControl("lblAnswer");        CheckBox rbSelected = null;        //将标准答案转化成数组
        string[] answers = lb.Text.Split(',');        //循环标准答案设置控件选中
        foreach (string i in answers)
        {
            rbSelected = (CheckBox)e.Item.FindControl("rb" + answers.ToString().ToUpper());
            rbSelected.Checked = true;
        }    }

Answer 7

这是前台的用法，后台方法加入
 onitemdatabound="Repeater1_ItemDataBound" //事件代码    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        Label lb = (Label)e.Item.FindControl("lblAnswer");
        RadioButton rbSelected = null;
        switch (lb.Text.ToLower())
        {
            case "a":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "b":
                rbSelected = (RadioButton)e.Item.FindControl("rbB");
                break;
            case "c":
                rbSelected = (RadioButton)e.Item.FindControl("rbC");
                break;
            default:
                rbSelected = (RadioButton)e.Item.FindControl("rbD");
                break;
        }
        rbSelected.Checked = true;
    }

注意

我用你的方法试了一遍，在
  switch (lb.Text.ToLower()) 这一行它提示未将对象引用到对象的实例，我用断点看了一下，lb的值为null,然后我自己改了一下

  foreach (RepeaterItem item in rpSingle.Items)
        {
            Label lb = (Label)item.FindControl("lblStuAnswer");
            RadioButton rbSelected = null;
            switch (lb.Text.ToUpper())
            {
                case "A":
                    rbSelected = (RadioButton)item.FindControl("rbA");
                    break;
                case "B":
                    rbSelected = (RadioButton)item.FindControl("rbB");
                    break;
                case "C":
                    rbSelected = (RadioButton)item.FindControl("rbC");
                    break;
                default:
                    rbSelected = (RadioButton)item.FindControl("rbD");
                    break;
                //case "D":
                //    rbSelected = (RadioButton)e.Item.FindControl("rbD");
                //    break;            }
            rbSelected.Checked = true;
        }
这次可以取到lb的值了，其余的都好了，但是最后一个却没有变，这是为什么呢？还请大侠帮我看一下

Answer 8

这是前台的用法，后台方法加入
 onitemdatabound="Repeater1_ItemDataBound" //事件代码    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        Label lb = (Label)e.Item.FindControl("lblAnswer");
        RadioButton rbSelected = null;
        switch (lb.Text.ToLower())
        {
            case "a":
                rbSelected = (RadioButton)e.Item.FindControl("rbA");
                break;
            case "b":
                rbSelected = (RadioButton)e.Item.FindControl("rbB");
                break;
            case "c":
                rbSelected = (RadioButton)e.Item.FindControl("rbC");
                break;
            default:
                rbSelected = (RadioButton)e.Item.FindControl("rbD");
                break;
        }
        rbSelected.Checked = true;
    }

注意

我用你的方法试了一遍，在
  switch (lb.Text.ToLower()) 这一行它提示未将对象引用到对象的实例，我用断点看了一下，lb的值为null,然后我自己改了一下

  foreach (RepeaterItem item in rpSingle.Items)
        {
            Label lb = (Label)item.FindControl("lblStuAnswer");
            RadioButton rbSelected = null;
            switch (lb.Text.ToUpper())
            {
                case "A":
                    rbSelected = (RadioButton)item.FindControl("rbA");
                    break;
                case "B":
                    rbSelected = (RadioButton)item.FindControl("rbB");
                    break;
                case "C":
                    rbSelected = (RadioButton)item.FindControl("rbC");
                    break;
                default:
                    rbSelected = (RadioButton)item.FindControl("rbD");
                    break;
                //case "D":
                //    rbSelected = (RadioButton)e.Item.FindControl("rbD");
                //    break;            }
            rbSelected.Checked = true;
        }
这次可以取到lb的值了，其余的都好了，但是最后一个却没有变，这是为什么呢？还请大侠帮我看一下最后一个不能选的图是这样的：

Answer 9

我试着只弄了一个题，没有选中，我断点看了一下foreach (RepeaterItem item in rpSingle.Items)这句它不进去，所以就跑不到后台语句了.......到底这是怎么了

Answer 10

  for (int i=0;i<rpSingle.Items.Count;i++)
        {
            Label lb = (Label)rpSingle.Items[i].FindControl("lblStuAnswer");
            RadioButton rbSelected = null;
            switch (lb.Text.ToUpper())
            {
                case "A":
                    rbSelected = (RadioButton)rpSingle.Items[i].FindControl("rbA");
                    break;
                case "B":
                    rbSelected = (RadioButton)rpSingle.Items[i].FindControl("rbB");
                    break;
                case "C":
                    rbSelected = (RadioButton)rpSingle.Items[i].FindControl("rbC");
                    break;
                default:
                    rbSelected = (RadioButton)rpSingle.Items[i].FindControl("rbD");
                    break;
                //case "D":
                //    rbSelected = (RadioButton)e.rpSingle.Items[i].FindControl("rbD");
                //    break;            }
            rbSelected.Checked = true;
        }修改循环

Answer 11

悲催的是还是不可以，还是最后一个选不中，如果只有一个的话也选不中，我插断点发现在i=0时，rpSingle.Items.Count的值为0，所以进不去，为什么会是零呢？不是20这个总体数？？然后这个rpSingle.Items.Count运行一次就加一个。好吧，既然这样我给rpSingle.Items.Count  +1，它就报错了，明明有一个item，怎么会没有呢？

Answer 12

前台，只是单选题
   <div id="paper">
       <asp:Repeater ID="rpSingle" runat="server" 
           onitemdatabound="rpSingle_ItemDataBound" >
           <HeaderTemplate>
               <strong>一、单选题</strong></HeaderTemplate>
           <ItemTemplate>
               <ul>
                   <li>
                       <%#(Container.ItemIndex+1)%>.&nbsp<asp:Label ID="lblSingleQ" runat="server" Text='<%#Eval("question") %>'></asp:Label>
                       <asp:Label ID="lblQid" runat="server" Text='<%#Eval("question_id") %>' Visible="false"></asp:Label>
                   </li>
                   <li>
                       <asp:RadioButton ID="rbA" runat="server" GroupName="s1" Text='<%#Eval("a") %>' />
                   </li>
                   <li>
                       <asp:RadioButton ID="rbB" runat="server" GroupName="s1" Text='<%#Eval("b") %>' />
                   </li>
                   <li>
                       <asp:RadioButton ID="rbC" runat="server" GroupName="s1" Text='<%#Eval("c") %>' />
                   </li>
                   <li>
                       <asp:RadioButton ID="rbD" runat="server" GroupName="s1" Text='<%#Eval("d") %>' />
                   </li>
                   <br />
                   <li>
                       <asp:Label ID="lblSingleStuPlay" runat="server" ForeColor="Blue" Text="学生答案是："></asp:Label><asp:Label
                           ID="lblStuAnswer" ForeColor="Blue" runat="server" Text='<%#Eval("student_answer")%>'></asp:Label>
                       &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                       <asp:Label ID="lblSinglePlay" runat="server" ForeColor="Blue" Text=" 正确答案是:"></asp:Label>
                       <asp:Label ID="lblAnswer" ForeColor="Blue" runat="server" Text='<%#Eval("answer") %>'></asp:Label>
                   </li>
               </ul>
           </ItemTemplate>
       </asp:Repeater>
        <hr />后台数据绑定：
 DataTable Singledt = OnLineBLL.Paper.GetStuPaper(Convert.ToInt32(Request.QueryString["courseid"]), lblStudentID.Text, 1);
            rpSingle.DataSource = Singledt;
            rpSingle.DataBind();
然后就是ItemDataBound事件的代码了