javascript更改后返回的值丢失

Question

当用户将鼠标移过时,我正在通过Javascript更改ImageButtons的ImageUrl.在提交时,我想检查ImageUrl属性.但是,更改的属性不会反映在后面的代码中.事实上,我也是通过javascript更新span标签,其更改后的值也没有反映在帖子后面.这些都是静态html元素.我没有动态创建任何这些,也没有在后面的代码中对它们进行任何操作.

HTML:

            <div style="margin: 20px 0 0 0; float: left;">
        <div class="divStars1" style="width: 130px; float: left;">
            <input type="image" name="ctl00$MainContent$ax1" id="MainContent_ax1" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$ax2" id="MainContent_ax2" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$ax3" id="MainContent_ax3" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$ax4" id="MainContent_ax4" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$ax5" id="MainContent_ax5" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />

        </div>
        <div style="margin-top: 3px; width: 600px; float: left;">
            <span>axs</span>
        </div>
    </div>
    <div style="margin: 20px 0 0 0; float: left;">
        <div class="divStars2" style="width: 130px; float: left;">
            <input type="image" name="ctl00$MainContent$bx1" id="MainContent_bx1" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$bx2" id="MainContent_bx2" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$bx3" id="MainContent_bx3" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$bx4" id="MainContent_bx4" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
            <input type="image" name="ctl00$MainContent$bx5" id="MainContent_bx5" class="stars" onmouseover="<code to flip image>" src="style/EmptyStar.png" style="height:20px;width:20px;" />
        </div>
        <div style="margin-top: 3px; width: 600px; float: left;">
            <span>bx blah blah</span>
        </div>
    </div>

使用Javascript:

        $(document).on("mouseover", "input.stars", function () {
        var score = 0;
        $("input.stars").each(function (index, element) {
            // element == this
            if ($(element).attr("src") == "style/FilledStar.png") {
                score = score + 1;
            };
        });
        score = score / 5;
        var n = score.toFixed(2);
        $("#MainContent_lblScore").text(n);
    });

btnSubmit_Click代码:

        For Each ctrl As Control In Me.divSkill1.Controls
        If (TypeOf ctrl Is ImageButton) Then
            Dim imgCtl As ImageButton = TryCast(ctrl, ImageButton)
            Dim x As String = imgCtl.ImageUrl 'HERE'S THE PROBLEM... x always equals original static value!
        End If

    Next

Answer 1

服务器对此类控件的客户端更改一无所知.可能您必须在隐藏字段或隐藏文本框中存储已由javascript更改的值,然后在服务器端收集此值.

希望这可以帮助

编辑:

如果你只想获得var n的值,你可以这样做:

// aspx;

<asp:HiddenField ID="HidScore" runat="server" />

/// javascript

$(document).on("mouseover", "input.stars", function () {
    var hid=$("#<%= HidScore.ClientID %>");


        var score = 0;
        $("input.stars").each(function (index, element) {
            // element == this
            if ($(element).attr("src") == "style/FilledStar.png") {
                score = score + 1;
            };
        });
        score = score / 5;
        var n = score.toFixed(2);
        $("#MainContent_lblScore").text(n);

    hid.val(n);
    });

然后在vb.net中获取值:HidScore.value

Answer 2

客户端对服务器端控件的更改通常将不保留或发布回服务器。

考虑创建一个隐藏的字段<asp:HiddenField />控件，并让您的JavaScript也更新该值。HiddenFields/ <input type="hidden" />将通过PostBack返回到服务器。然后，您的代码将需要检查的HiddenField可能更改或更新，并将这些更改路由回ImageButton ImageUrl属性。