Javascript 如何使用javascript访问视图状态？
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How to access viewstate using javascript?
提问by Sukhjeevan
I am trying to access view-state in client side but following exception coming :
我正在尝试访问客户端的视图状态，但出现以下异常：
JAVASCRIPT:
爪哇脚本：
<script language="javascript" type="text/javascript">
var vCode = '<%=ViewState("code")%>';
alert(dateView);
</script>
CODE BEHIND:
背后的代码：
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
ViewState("code") = "EE"
End Sub
Anybody suggest me how to do it?
有人建议我怎么做吗？
回答by jerjer
I would suggests to use RegisterHiddenField than mixing server/js codes:
我建议使用 RegisterHiddenField 而不是混合服务器/js 代码：
You may try this sample:
你可以试试这个示例：
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
ViewState("code") = "EE"
Page.ClientScript.RegisterHiddenField("vCode", ViewState("code"))
End Sub
On your javascript:
在您的 javascript 上：
var vCode = document.getElementById("vCode");
alert(vCode);
回答by Oded
You can simply access the hidden form element that holds the viewstate.
您可以简单地访问保存视图状态的隐藏表单元素。
The name of the control is __viewstate.
控件的名称是__viewstate.
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="..." />
var vCode = documents.forms[0]['__VIEWSTATE'].Value;
alert(dateView);
Of course, this will give you the encrypted/encoded/compressed viewstate.
当然，这会给你加密/编码/压缩的视图状态。
If you want specific values from it, you may find it better to record them in hidden fields and access those.
如果您想从中获取特定值，您可能会发现将它们记录在隐藏字段中并访问它们会更好。
回答by Niloofar
The Page.ClientScript.RegisterHiddenField did not work for me and returned null. You can do like this:
Page.ClientScript.RegisterHiddenField 对我不起作用并返回 null。你可以这样做：
1-First solution:define a hidden field and make sure you set runat=server
1-第一个解决方案：定义一个隐藏字段并确保设置 runat=server
<input type="hidden" id="myhiddenField" runat="server" value="" />
then in your code behind assign any value you want to it
然后在你后面的代码中分配你想要的任何值
myhiddenField.Value= ViewState["name"].ToString();// or assign any value you want
in your javascript access it like this:
在您的 javascript 中像这样访问它：
<script type="text/javascript">
function test()
{
var name = document.getElementById('myhiddenField').value;
alert(name)
}
</script>
2-Second solution
2秒解决方案
In case for some reasons you don't want to have a server input control you can put the hidden field in a literal tag
如果出于某些原因您不想拥有服务器输入控件，您可以将隐藏字段放在文字标记中
<asp:literal id="literal1" runat="server"><input type="hidden" id="myhiddenField" value="{0}"/></asp:literal>
and then assign a value to the literal in codebehind like this
然后像这样为代码隐藏中的文字赋值
literal1.Text = string.Format(literal1.Text, "somevalue"); // somevlue can be your ViewState value
then access it in javascript as usual
然后像往常一样在javascript中访问它
var name = document.getElementById('myhiddenField').value;
alert(name)
Note: if you are using update panels put the hiddenfields inside the contenttemplate tag of the updatepanel
注意：如果您使用更新面板，请将隐藏字段放在更新面板的 contenttemplate 标签内
